Modern Day Mosasaurs
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Transcript of Modern Day Mosasaurs
Mosasaurs (clade Mosasauridae) evolved during the late Mesozoic when a group of monitorlike lizards entered the ocean. These toothy, serpentine
predators might have seemed chunky and illmade when compared to the other marine predators of the time. However, while the ichthyosaurs went extinct
before the end of the Cretaceous and the plesiosaurs soon after, the mosasaurs have gone on to become one of the largest and most diverse clades of marine
vertebrates.
Most presentday mosasaurs are quite unlike their serpentine forebears. Whatever environmental catastrophe that mauled the archaeocetaceans in our world
almost had the same effect on the Late Eocene mosasaurs. Gone were the huge, 15m long tylosaurine seaserpents and their kin, never to return.
ANGUILLACERTIDAE (TiLung)
Years after specbiologists had concluded that none of the ancestral, longbodied mosasaurs
survived to the present day, the illustrious Tiina Aumala proved the existence of Anguillacerta
sinensis, the tilung.
(fig. 1) Yangtze mosasaur, Anguillacerta sinensis (Central and southern Asia)
Anguillacerta possesses nostrils placed above the eyes, as in the saurocetes, but its body is long, the tail is laterally flattened and possesses no fluke, and the
hind limbs are missing altogether. This cryptic piscivore is clearly a mosasaur, but is only distantly related to the saurocetes and is loosely allied with the
archaic forms that supposedly died out at the end of the Eocene.
ARCHAEOSAUROCETACIDAE (Apeps)
The earlyEocene radiation that produced the eellike river mosasaurs also resulted in the birth of the saurocetes, the most common of the extant mosasaur
groups. The first saurocetes, from the Eocene, are similar to modern forms, but fossil impressions show that they did not possess the paired tailfluke of the
advanced lizardwhales. Only a single species remains of this once mighty group.
The apep is a piscivorous aquatic lizard that today seems to be restricted to the
river Nile. Apeps can reach the length of 4.5 meters, though such venerable
individuals are rarely seen, and 23 meter long mosasaurs are more common.
(fig. 2) Apep, Apep aegypianus (Northern Africa)
Though at first the apep seems to resemble the serpentine longbodied yangtze mosasaur, it is acutally the last remaining archaeosaurocetid, or ansestral
saurocete, closely resembling fossil species such as Balaenanguis. Based on the patchy fossil record, genus Apep seems to date back at least to the
Oligocene (and possibly the Eocene) and has barely changed at all after it first appeared.
GIGANTOSERPENTIDAE (Leviathans)
The first evidence of one of Spec's most enigmatic seagiants washed up on a stony beach in eastern Africa after a particularly stormy night. The discoverer,
a certain Calvin Hobb, was apparently walking dangerously near the choppy shore when a sudden, violent surge practically dumped the specimen at his feet.
It was a cylindrical mass of rotting flesh over twelve metres in length. Within one end of the carcass, researchers recovered the twometre long skull minus the
lower jaw, the vertebral column up to the 17th dorsal and parts of right forepaddle. An examination of the bones made it clear that the carcass, now dubbed
"Hobb's Leviathan" represented a new species of mosasaur, but of what kind? Popular initial reports claimed that it represented a "living fossil", an archaic
longbodied mosasaurid that had escaped the Eocene extinction. More cautious researchers noted apparent similarities with the needlelike teeth and gracile
bodyform of the Yangtze mosasaur, suggesting a relationship with anguillacertids. Regardless of where it fitted amongst the Mosasauria, the skull and
vertebrae were sufficient cause to warrant it's description as a new species Gigantoserpens microdon, "the teenytoothed gigantic serpent"
(fig. 3) Early reconstruction of Hobb's Leviathan done prior to its description. Illustration by Tiina Aumala
Despite the incompleteness of the remains, the idea of a giant seaserpent was irresistable and a number of popular reconstructions depicted the
animal as an vast eellike creature with a stated length of over 25 metres. Soon sightings of giant killer serpents began cropping up everywhere
from the Caribbean to the bottom of Tiina's beer stein. Hoaxes pertaining to leviathanrelated fatalities at sea soon led to much hysteria. Nothing
more was heard from the real Gigantoserpens for over three years until a vessel surveying the west coast of South America produced blurry
photographs of a huge sea creature near San Ambrosio. They appeared to show nothing less than a supposedly extinct longnecked plesiosaur,
an animal that seemed to possess a small head, longneck and a bulbous, flippered body. An expedition to learn more of this creature was
hastily dispatched and it was soon ascertained that these "plesiosaurs" were in fact the real Hobb's leviathans.
The true appearance of these giant mosasaurs was completely
unexpected and nothing like the snakelike hypothetical
reconstructions. Instead of a vicious predator, the real leviathan
proved to be a sluggish, passive hunter of small prey. Rather than a
relic of the Eocene or some giant oceangoing rivermosasaur,
Gigantoserpens turned out to be a highly aberrant truesaurocetean
although different enough to be placed, along with subsequently
discovered Pliocene fossil forms, into a new clade the
Gigantoserpentidae.
(fig. 4)A living Gigantoserpens photographed off the west coast of South America. At "only" 11 metres in length, this is a relatively small individual.
HOBB'S LEVIATHAN DESCRIBED
(fig. 5)Skeletal silhouette of Hobb's leviathan alongside the incomplete holotype specimen and a human diver (diver courtesy Tiina Aumala)
Gigantoserpens is a bizarre saurocetacean that can reach a length of 21 metres and weigh in at an estimated 60 tonnes making it by far the
largest known squamate. The head is comparatively small and flat, sitting on a very short neck behind which sprout a pair of small flippers.
These are often held against the neck and can be difficult to discern from a distance.
The anterior dorsal vertebrae are lightweight while the associated ribs are greatly reduced in size. Thus in life, the forequarters of the animal
appear slender and snakelike, creating the illusion of an elongated neck. Further down the trunk the vertebrae become drastically larger and
more robust while the length and girth of the ribs increases causing the body to balloon out. The pelvic girdle and hindflippers are incredibly
large by mosasaur standards whilst the tail is exceptionally long and deep with prominant lateral keels, terminating in a huge caudalfin. A low,
triangular dorsal fin is located midway along the tail.
The dentition consists of numerous fine needlelike teeth and the lower jaw is loosely attached to the skull
allowing for a very wide gape. The interior of the mouth contains a series of rugosities called gnathochromes
which are infested with growths of luminescent bacteria that are clearly visible when the jaws are opened.
(fig. 6) (left) Frontal view of open mouth showing gnathochromes rugosities on which grow clusters of luminescent bacteria. The pterygoid teeth have been reduced to a
small row of nodules that are not externally visible on large adults. (right) Appearance of glowing gnathochromes in dark water. The precise arrangement varies between
individuals.
(fig. 7)Near the Azores, a Hobb's leviathan disappears in a great cloud of poo.
One unusual internal feature is a large sac on the lower intestine that can be filled with over 90 litres of reddishbrown syrupy faecal matter. When threatened
by a large carnivore, this liquid is expelled in a great, dense cloud that confuses or repels the attacker and gives the slowmoving leviathan the chance of
escape. A similar strategy is used (on a much smaller scale) by the HomeEarth pygmy sperm whales of the family Kogiidae.
The leviathan is primarily a mesopelagic predator that has been characterised as a "mosasaur trying to be an elasmosaur". Based on the stomach contents of
stranded individuals, it mostly feeds on nonshelly pelagic prey of up to a metre in length. It is not a choosy feeder and takes whatever happens to be
abundant in the area. While it has yet to be witnessed, it's feeding strategy probably involves cruising through the inky blackness with it's jaws agape. The
twinkling bacterial colonies in it's mouth give the impression of a swarm of bioluminescent plankton attracting shoals of fish, shrimp and squid to within easy
striking distance. The slender forequarters can curl and dart around with great speed, allowing it to snap up fasterswimming prey. The presence of injested
echinoderms and small skates suggest it also forages on the benthos, perhaps while gathering stones for ballast. One particularly scarred individual that was
recently stranded on New Caledonia was found to have a belly full of piranhakeets. The giant hindflippers are used for stability and steering, effectively filling
the role of pectoral fins on a more conventional sea creature. The stubby forepaddles seem to act as canard foreplanes, conferring a degree of hydrodynamic
stability to the anterior of the animal when on the move. While feeding, they are probably held conformally to avoid drag as the neck sweeps around.
Alternatively the forelimbs might play a role in sheperding prey although they seem a little too far from the mouth for this. Strandings and sightings indicate a
cosmopolitan species of deep offshore tropical to warm temperate seas. Although sparsely distributed, they are sometimes found in large feeding
concentrations and appear to have a habitat requirement for deep slope waters with steep depth gradients. Except for infrequent forays to the surface for air,
they follow the vertical migration of their prey, cruising at depths of over 900m during the day before rising to within 100m of the surface at night. Much
remains to be discovered about these remarkable giants and as yet we know nothing of their seasonal migrations, reproduction and development.
SAUROCETACIDAE (Mosarks and lizardwhales)
(fig. 8) A sampling of saurocetacidae (with apep)
1. Prownose lizardwhale
2. Apep
3. Zahn
4. Mosapoise
5. Mosark
6. Sawsnout lizardwhale
7. Longtailed lizardwhale
8. Sakhala
Currently the most highly specialized of marine reptiles, saurocetes do not bear much resemblance to their seaserpent ancestors, and rather resemble the
dolphins and whales of RL. Like the Jurassic ichthyosaurs before them and the odontocetaceans of our Earth, the ancestors of these creatures were long
bodied serpentine inshore predators (see above) that developed an increasingly fishlike body for a pelagic existence.
Saurocetes are fishlike marine squamates ranging from 1.5 to 15 metres in length. They are broadly analogous with our world's odontocetes but have not
produced a biggame carnivore in the same league as the orca. The scales have been completely lost and have been replaced with a smooth, leathery hide.
The paired nostrils are positioned at the top of the head. Propulsion is by strokes of a fishlike tail bearing 2 vertical flukes. All saurocetes are viviparous.
The precursors of the saurocetaceans were the huge predatory mosasaurs, marine squamates that evolved in the Cretaceous and were amongst the top
ocean predators from the Santonian to the Eocene. The decline of inland seas in the Maastrichtian put pressure on the mosasaurs to more fully exploit the
open oceans. One lineage abandoned the serpentine mosasaurbody, becoming more fishlike with a large falcate caudal fin replacing the simple spatulate
form.
While the Late Eocene disaster decimated their longbodied kin, the early saurocetaceans flourished, developing ever larger and larger forms. Today over 40
species ply the tropical to warm temperate oceans of the world, feeding mainly on cephalopods and small fish. However, they have been unable to venture
into the cooler sea. Those rich, polar killing grounds are the domains of warmblooded predators: birds like seaguins and penguins, and mammals like
walduks.
While HomeEarth's cetaceans cover a wide range of body types (from dolphins to whales), sarurocetes do not display so wide a diversity. There are no
filterfeeding mosasaurs, and the disparity between large and small species is relatively minimal. However, clear distinctions within Saurocetacidae do exist.
The carcharosaurines, or mosarks, are powerfullybuilt predators. Some, like the zahn, are truly enormous.
The mosark, cousin of the sakhala and zahn, is a 810 m long
predator of temperate oceans around the world. A mediumsized
pelagic predator, the mosark gained its name mainly from its shark
like appearance and behaviour, and many of its relatives are also often
unofficially referred to as mosarks for the same reason.
(fig. 9) Mosark, Pristrix monstrum (worldwide)
This lizardwhale is in many respects similiar to the zahn, though smaller and swifter. Though their diet mostly consists of cephalopods and fish, mosarks are
also known to attack small lizardwhales and other marine vertebrates.
The zahn is one of the largest lizardwhales. This 14 m
long solitary predator is large enough to swallow small
wingsquid whole and tear fully grown mantasquid into
pieces. Zhans attack just about anything big enough to
fit between their enormous jaws, including seabirds,
rays, sharks, swimming or wading dinosaurs, other
lizardwhales and inflatable boats filled with marine
biologists. There have been at least two unfortunate
incidents where Spec scientists have nearly ended up
in a zahn's bellythey were apparently saved only by
the foul taste of the boat. After that, small rubber
boats haven't been used in zahninfested waters.
(fig. 10) Zahn, Carcharosaurus atrox (Equatorial)
(fig. 11) Chubby mosark, Carcharosaurus crassus (Western Atlantic)
Warmed by the Gulf Stream, the waters off the coast of eastern North America are home to many predators, from walduks to sharks, but the most feared of
all is the chubby mosark. These odd little mosasaurs dart around the shallows from Florida to Newfoundland, snatching up anything that moves.
Despite its common name, the chubby mosark is only distantly related to the true mosarks (genus Pristrix). These creatures, are, in fact, close kin to the
zahns, massive, orcalike predators that hunt upper levels of the deep ocean. The chubby mosark, on the other hand, is one of several Carcharosaurus
lineages that have adapted for a life hunting the nutrientrich shallows of the continental shelves. These hunters are small, and rely upon their sensitive
Jacobson's organs to taste the water and home in on prey, rather than the easily confused eye. As a result, the eyes of the chubby mosark are rather small
and not very sensitive, while their chemical sense is superb.
Another way in which the chubby mosarks distinguish themselves is in their geographical range, which extends further north than any other marine mosasaur.
Although they winter in the warm waters off the coast of Florida, chubby mosasaurs spend the summer months rearing their pups in the Gulf of St. Lawrence.
This behavior is quite useful, since the habitat is devoid of competing mosasaurs, and the native pods of selkies make a tasty snack for the larger reptiles.
However, the northern water, although made bearable by the Gulf Stream, are still frigid to the coldblooded mosasaurs, and so chubby mosarks must
produce internal "coats" of insulating blubber, the source of their name.
(fig. 12) Sakhala, Carcharosaurus velox (Great Barrier Reef)
The Sakhala is a small (3 m long) and swift sharklike mosasaur that lives in the Great Barrier Reef. Though it mainly eats small fish and cephalopods, it may
attack anything smaller than a meter across if it looks edible.
(fig. 13) Nodens, Nodens incredibilis (Great Barrier Reef)
Ironically the largest known saurocete was not first discovered in the sea, but on dry land. During the first years of spexploration, some of the spexplorers
studying seaside ecosystems came across a gargantuan rotting hulk that had been washed ashore. It 18 meters long and was easily recognized as a
lizardwhale, but as the spexplorers lacked the appropriate equipment to transport that tonnage of meat, and the carcass was in such an advanced state of
decomposition that a further analysis was impossible to make at the time. The remains were hastily measured and photographed, and later some of the
skeletal remains were retrieved. These fragments became the holotype specimen of Nodens incredibilis.
Later, several other Nodens skeletons were discovered, and the largest of these, consisting of little more than a skull measuring over 4 meters long, lead to an
estimate of the adult size of Nodens, some 20 meters long, making it longest known marine vertebrate on Spec. It still took some time before the first verified
eyewitness sighting of a living specimen, but through a lucky coincidence, a group of marine biologists happened to be near a Nodens mating area, and
managed to film the animals both above and under water.
The film revealed that much of the forequarters of the giant lizardwhales were covered in curious looking scars, some resembling those left by giant squid
tentacles on sperm whales and others more unusual in appearance. It was deduced that the main diet of Nodens consisted of giant cephalopods, but the
peculiar scars lead to some dispute over what had caused them. Some claimed the lesions were bitemarks of some kind, while others blamed the infamous
great ktulu, which was reported as having feeding tentacles ending in handlike extensions covered in wicked hooks. A photograph of a large Nodens
individual with a severed end of a tentacle ending in just such fingerlike extensions still stuck on its skin only helped to fuel the controversy.
While the actual hunting and feeding of Nodens is yet to be observed, we do know that they are solitary most of the year and find their prey in the murky
depths of the ocean teeming with myriads of exotic cephalopod species. These saurocetes seem to fill the niche of HE sperm whales, although we can only
speculate at the differences in their hunting strategies. Despite having eyes not much larger than a human head, they are known to have a keen vision
especially in the dark. It is worth noting that Nodens are much more likely to move close to the surface at night than during the day.
While Nodens seemingly has a lot in common with mosarks, the latest analysis places it closest to nauticratisaurs. Though reports of Nodens individuals
longer than 20,5 meters are unverified, it still holds the record of the largest known mosasaur, being more massive (though not quite as long) as the leviathan.
Longtailed lizardwhales are a common species that form large schools off the western
coast of North America. They feed on a variety of small fish and cephalopods.
(fig. 13) Longtailed lizardwhale Naucratisaurus gracilis (Pacific)
A
close relative of the longtailed lizardwhale, the 45 meter long
azure lizardwhale forms large pods off the in the warm waters of the
Gulf Stream.
(fig. 14) Azure lizardwhale Naucratisaurus atlanticus (Atlantic)
The saurocetacines, on the other hand, are the more streamlined lizardwhales. Some possess long snouts and closely resemble the ichthyosaurs of Earth's
past and the dolphins of our home timeline.
One of the larger saurocetaceans, the prownose lizardwhale usually lives
alone but feeding aggregations of over 50 have been sighted. There are no
teeth in the upper jaw while 1214 conical teeth of each side of the dentary.
The prownose lizardwhale feeds primarily on cehalopods, including huge
barrelfish.
(fig. 15) Prownose lizardwhale Saurocetaceus pelagios (worldwide)
This cephalopodhunting saurocetacean lives in the Indian
ocean. Though closely related to the prownose lizardwhale,
Choo's lizardwhales rarely grow larger than 7 meters long.
These animals greatly resemble the Mesozoic ichtyosaurs,
which at first caused some confusion among the first
explorers of Spec.
(fig. 16) Choo's lizardwhale Saurocetaceus brianchooi (Indian Ocean)
(fig. 17) Mosapoise, Phocoenalacerta nigra (Equatorial Pacific)
The mosapoise is a 3.5 meters long saurocete specialized mostly on ammonoids, crabs, shellfishes and other hardshelled marine invertebrates it crushes with
its impressive battery of teeth.
The sawsnout lizardwhale, while clearly a saurocete, does not fit in with either the mosarks or the mosapoises. Some have allied this odd creature to apep,
the Nile mosasaur, but further studies are necessary to prove such a theory.
The sawsnout lizardwhale is undoubtedly one of the weirdest mosasaurs
in existence. Its upper jaw is disproportionally long and armed with
sharp outwardspointing teeth. Sawsnout lizardwhales use this weapon
to stun fastmoving prey and to rake out buried prey from the bottom.
(fig. 18) Sawsnout lizardwhale, Pristisaurus peculiaris(Caribbean)
Brian Choo, Daniel Bensen, and Tiina Aumala
,=Anguillacertidae=Anguillacerta sinensis (Yangtze mosasaur)
=Mosasauridae=|
| ,=Archaeosaurocetacidae=Apep aegyptianus (Nile Mosasaur)
`=|
| ,=Gigantoserpentidae=Gigantoserpens microdon (Hobb's leviathan)
| |
| | ,=Pristrix monstrum Mosark
| | ,=|
| | | | ,=C. atrox (Zahn)
| | | `=Carcharosaurus=|
| | | | ,=C. crassus (Chubby mosark)
| | | `=|
| | | `=C. velox (Sakhala)
| | ,=|
| | | |=? Nodens incredibilis (Nodens)
| | | |
| | | | ,=N. gracilis (Longtailed lizardwhale)
| | | `=Naucratisaurus=|
| | | `=N. atlanticus (Azure lizardwhale)
| | ,=|
| | | | ,=S. pelagios (Prownose lizardwhale)
| | | | ,=Saurocetaceus=|
| | | | | `=S. brianchooi (Choo's lizardwhale)
| | | `=|
| | | `=Phocoenalacerta nigra (Mosapoise)
`=Saurocetaciodea=| |
`=Saurocetacidae=|
`=Pristisaurus peculiaris (Sawsnout lizardwhale)
Back
Mosasaurs (clade Mosasauridae) evolved during the late Mesozoic when a group of monitorlike lizards entered the ocean. These toothy, serpentine
predators might have seemed chunky and illmade when compared to the other marine predators of the time. However, while the ichthyosaurs went extinct
before the end of the Cretaceous and the plesiosaurs soon after, the mosasaurs have gone on to become one of the largest and most diverse clades of marine
vertebrates.
Most presentday mosasaurs are quite unlike their serpentine forebears. Whatever environmental catastrophe that mauled the archaeocetaceans in our world
almost had the same effect on the Late Eocene mosasaurs. Gone were the huge, 15m long tylosaurine seaserpents and their kin, never to return.
ANGUILLACERTIDAE (TiLung)
Years after specbiologists had concluded that none of the ancestral, longbodied mosasaurs
survived to the present day, the illustrious Tiina Aumala proved the existence of Anguillacerta
sinensis, the tilung.
(fig. 1) Yangtze mosasaur, Anguillacerta sinensis (Central and southern Asia)
Anguillacerta possesses nostrils placed above the eyes, as in the saurocetes, but its body is long, the tail is laterally flattened and possesses no fluke, and the
hind limbs are missing altogether. This cryptic piscivore is clearly a mosasaur, but is only distantly related to the saurocetes and is loosely allied with the
archaic forms that supposedly died out at the end of the Eocene.
ARCHAEOSAUROCETACIDAE (Apeps)
The earlyEocene radiation that produced the eellike river mosasaurs also resulted in the birth of the saurocetes, the most common of the extant mosasaur
groups. The first saurocetes, from the Eocene, are similar to modern forms, but fossil impressions show that they did not possess the paired tailfluke of the
advanced lizardwhales. Only a single species remains of this once mighty group.
The apep is a piscivorous aquatic lizard that today seems to be restricted to the
river Nile. Apeps can reach the length of 4.5 meters, though such venerable
individuals are rarely seen, and 23 meter long mosasaurs are more common.
(fig. 2) Apep, Apep aegypianus (Northern Africa)
Though at first the apep seems to resemble the serpentine longbodied yangtze mosasaur, it is acutally the last remaining archaeosaurocetid, or ansestral
saurocete, closely resembling fossil species such as Balaenanguis. Based on the patchy fossil record, genus Apep seems to date back at least to the
Oligocene (and possibly the Eocene) and has barely changed at all after it first appeared.
GIGANTOSERPENTIDAE (Leviathans)
The first evidence of one of Spec's most enigmatic seagiants washed up on a stony beach in eastern Africa after a particularly stormy night. The discoverer,
a certain Calvin Hobb, was apparently walking dangerously near the choppy shore when a sudden, violent surge practically dumped the specimen at his feet.
It was a cylindrical mass of rotting flesh over twelve metres in length. Within one end of the carcass, researchers recovered the twometre long skull minus the
lower jaw, the vertebral column up to the 17th dorsal and parts of right forepaddle. An examination of the bones made it clear that the carcass, now dubbed
"Hobb's Leviathan" represented a new species of mosasaur, but of what kind? Popular initial reports claimed that it represented a "living fossil", an archaic
longbodied mosasaurid that had escaped the Eocene extinction. More cautious researchers noted apparent similarities with the needlelike teeth and gracile
bodyform of the Yangtze mosasaur, suggesting a relationship with anguillacertids. Regardless of where it fitted amongst the Mosasauria, the skull and
vertebrae were sufficient cause to warrant it's description as a new species Gigantoserpens microdon, "the teenytoothed gigantic serpent"
(fig. 3) Early reconstruction of Hobb's Leviathan done prior to its description. Illustration by Tiina Aumala
Despite the incompleteness of the remains, the idea of a giant seaserpent was irresistable and a number of popular reconstructions depicted the
animal as an vast eellike creature with a stated length of over 25 metres. Soon sightings of giant killer serpents began cropping up everywhere
from the Caribbean to the bottom of Tiina's beer stein. Hoaxes pertaining to leviathanrelated fatalities at sea soon led to much hysteria. Nothing
more was heard from the real Gigantoserpens for over three years until a vessel surveying the west coast of South America produced blurry
photographs of a huge sea creature near San Ambrosio. They appeared to show nothing less than a supposedly extinct longnecked plesiosaur,
an animal that seemed to possess a small head, longneck and a bulbous, flippered body. An expedition to learn more of this creature was
hastily dispatched and it was soon ascertained that these "plesiosaurs" were in fact the real Hobb's leviathans.
The true appearance of these giant mosasaurs was completely
unexpected and nothing like the snakelike hypothetical
reconstructions. Instead of a vicious predator, the real leviathan
proved to be a sluggish, passive hunter of small prey. Rather than a
relic of the Eocene or some giant oceangoing rivermosasaur,
Gigantoserpens turned out to be a highly aberrant truesaurocetean
although different enough to be placed, along with subsequently
discovered Pliocene fossil forms, into a new clade the
Gigantoserpentidae.
(fig. 4)A living Gigantoserpens photographed off the west coast of South America. At "only" 11 metres in length, this is a relatively small individual.
HOBB'S LEVIATHAN DESCRIBED
(fig. 5)Skeletal silhouette of Hobb's leviathan alongside the incomplete holotype specimen and a human diver (diver courtesy Tiina Aumala)
Gigantoserpens is a bizarre saurocetacean that can reach a length of 21 metres and weigh in at an estimated 60 tonnes making it by far the
largest known squamate. The head is comparatively small and flat, sitting on a very short neck behind which sprout a pair of small flippers.
These are often held against the neck and can be difficult to discern from a distance.
The anterior dorsal vertebrae are lightweight while the associated ribs are greatly reduced in size. Thus in life, the forequarters of the animal
appear slender and snakelike, creating the illusion of an elongated neck. Further down the trunk the vertebrae become drastically larger and
more robust while the length and girth of the ribs increases causing the body to balloon out. The pelvic girdle and hindflippers are incredibly
large by mosasaur standards whilst the tail is exceptionally long and deep with prominant lateral keels, terminating in a huge caudalfin. A low,
triangular dorsal fin is located midway along the tail.
The dentition consists of numerous fine needlelike teeth and the lower jaw is loosely attached to the skull
allowing for a very wide gape. The interior of the mouth contains a series of rugosities called gnathochromes
which are infested with growths of luminescent bacteria that are clearly visible when the jaws are opened.
(fig. 6) (left) Frontal view of open mouth showing gnathochromes rugosities on which grow clusters of luminescent bacteria. The pterygoid teeth have been reduced to a
small row of nodules that are not externally visible on large adults. (right) Appearance of glowing gnathochromes in dark water. The precise arrangement varies between
individuals.
(fig. 7)Near the Azores, a Hobb's leviathan disappears in a great cloud of poo.
One unusual internal feature is a large sac on the lower intestine that can be filled with over 90 litres of reddishbrown syrupy faecal matter. When threatened
by a large carnivore, this liquid is expelled in a great, dense cloud that confuses or repels the attacker and gives the slowmoving leviathan the chance of
escape. A similar strategy is used (on a much smaller scale) by the HomeEarth pygmy sperm whales of the family Kogiidae.
The leviathan is primarily a mesopelagic predator that has been characterised as a "mosasaur trying to be an elasmosaur". Based on the stomach contents of
stranded individuals, it mostly feeds on nonshelly pelagic prey of up to a metre in length. It is not a choosy feeder and takes whatever happens to be
abundant in the area. While it has yet to be witnessed, it's feeding strategy probably involves cruising through the inky blackness with it's jaws agape. The
twinkling bacterial colonies in it's mouth give the impression of a swarm of bioluminescent plankton attracting shoals of fish, shrimp and squid to within easy
striking distance. The slender forequarters can curl and dart around with great speed, allowing it to snap up fasterswimming prey. The presence of injested
echinoderms and small skates suggest it also forages on the benthos, perhaps while gathering stones for ballast. One particularly scarred individual that was
recently stranded on New Caledonia was found to have a belly full of piranhakeets. The giant hindflippers are used for stability and steering, effectively filling
the role of pectoral fins on a more conventional sea creature. The stubby forepaddles seem to act as canard foreplanes, conferring a degree of hydrodynamic
stability to the anterior of the animal when on the move. While feeding, they are probably held conformally to avoid drag as the neck sweeps around.
Alternatively the forelimbs might play a role in sheperding prey although they seem a little too far from the mouth for this. Strandings and sightings indicate a
cosmopolitan species of deep offshore tropical to warm temperate seas. Although sparsely distributed, they are sometimes found in large feeding
concentrations and appear to have a habitat requirement for deep slope waters with steep depth gradients. Except for infrequent forays to the surface for air,
they follow the vertical migration of their prey, cruising at depths of over 900m during the day before rising to within 100m of the surface at night. Much
remains to be discovered about these remarkable giants and as yet we know nothing of their seasonal migrations, reproduction and development.
SAUROCETACIDAE (Mosarks and lizardwhales)
(fig. 8) A sampling of saurocetacidae (with apep)
1. Prownose lizardwhale
2. Apep
3. Zahn
4. Mosapoise
5. Mosark
6. Sawsnout lizardwhale
7. Longtailed lizardwhale
8. Sakhala
Currently the most highly specialized of marine reptiles, saurocetes do not bear much resemblance to their seaserpent ancestors, and rather resemble the
dolphins and whales of RL. Like the Jurassic ichthyosaurs before them and the odontocetaceans of our Earth, the ancestors of these creatures were long
bodied serpentine inshore predators (see above) that developed an increasingly fishlike body for a pelagic existence.
Saurocetes are fishlike marine squamates ranging from 1.5 to 15 metres in length. They are broadly analogous with our world's odontocetes but have not
produced a biggame carnivore in the same league as the orca. The scales have been completely lost and have been replaced with a smooth, leathery hide.
The paired nostrils are positioned at the top of the head. Propulsion is by strokes of a fishlike tail bearing 2 vertical flukes. All saurocetes are viviparous.
The precursors of the saurocetaceans were the huge predatory mosasaurs, marine squamates that evolved in the Cretaceous and were amongst the top
ocean predators from the Santonian to the Eocene. The decline of inland seas in the Maastrichtian put pressure on the mosasaurs to more fully exploit the
open oceans. One lineage abandoned the serpentine mosasaurbody, becoming more fishlike with a large falcate caudal fin replacing the simple spatulate
form.
While the Late Eocene disaster decimated their longbodied kin, the early saurocetaceans flourished, developing ever larger and larger forms. Today over 40
species ply the tropical to warm temperate oceans of the world, feeding mainly on cephalopods and small fish. However, they have been unable to venture
into the cooler sea. Those rich, polar killing grounds are the domains of warmblooded predators: birds like seaguins and penguins, and mammals like
walduks.
While HomeEarth's cetaceans cover a wide range of body types (from dolphins to whales), sarurocetes do not display so wide a diversity. There are no
filterfeeding mosasaurs, and the disparity between large and small species is relatively minimal. However, clear distinctions within Saurocetacidae do exist.
The carcharosaurines, or mosarks, are powerfullybuilt predators. Some, like the zahn, are truly enormous.
The mosark, cousin of the sakhala and zahn, is a 810 m long
predator of temperate oceans around the world. A mediumsized
pelagic predator, the mosark gained its name mainly from its shark
like appearance and behaviour, and many of its relatives are also often
unofficially referred to as mosarks for the same reason.
(fig. 9) Mosark, Pristrix monstrum (worldwide)
This lizardwhale is in many respects similiar to the zahn, though smaller and swifter. Though their diet mostly consists of cephalopods and fish, mosarks are
also known to attack small lizardwhales and other marine vertebrates.
The zahn is one of the largest lizardwhales. This 14 m
long solitary predator is large enough to swallow small
wingsquid whole and tear fully grown mantasquid into
pieces. Zhans attack just about anything big enough to
fit between their enormous jaws, including seabirds,
rays, sharks, swimming or wading dinosaurs, other
lizardwhales and inflatable boats filled with marine
biologists. There have been at least two unfortunate
incidents where Spec scientists have nearly ended up
in a zahn's bellythey were apparently saved only by
the foul taste of the boat. After that, small rubber
boats haven't been used in zahninfested waters.
(fig. 10) Zahn, Carcharosaurus atrox (Equatorial)
(fig. 11) Chubby mosark, Carcharosaurus crassus (Western Atlantic)
Warmed by the Gulf Stream, the waters off the coast of eastern North America are home to many predators, from walduks to sharks, but the most feared of
all is the chubby mosark. These odd little mosasaurs dart around the shallows from Florida to Newfoundland, snatching up anything that moves.
Despite its common name, the chubby mosark is only distantly related to the true mosarks (genus Pristrix). These creatures, are, in fact, close kin to the
zahns, massive, orcalike predators that hunt upper levels of the deep ocean. The chubby mosark, on the other hand, is one of several Carcharosaurus
lineages that have adapted for a life hunting the nutrientrich shallows of the continental shelves. These hunters are small, and rely upon their sensitive
Jacobson's organs to taste the water and home in on prey, rather than the easily confused eye. As a result, the eyes of the chubby mosark are rather small
and not very sensitive, while their chemical sense is superb.
Another way in which the chubby mosarks distinguish themselves is in their geographical range, which extends further north than any other marine mosasaur.
Although they winter in the warm waters off the coast of Florida, chubby mosasaurs spend the summer months rearing their pups in the Gulf of St. Lawrence.
This behavior is quite useful, since the habitat is devoid of competing mosasaurs, and the native pods of selkies make a tasty snack for the larger reptiles.
However, the northern water, although made bearable by the Gulf Stream, are still frigid to the coldblooded mosasaurs, and so chubby mosarks must
produce internal "coats" of insulating blubber, the source of their name.
(fig. 12) Sakhala, Carcharosaurus velox (Great Barrier Reef)
The Sakhala is a small (3 m long) and swift sharklike mosasaur that lives in the Great Barrier Reef. Though it mainly eats small fish and cephalopods, it may
attack anything smaller than a meter across if it looks edible.
(fig. 13) Nodens, Nodens incredibilis (Great Barrier Reef)
Ironically the largest known saurocete was not first discovered in the sea, but on dry land. During the first years of spexploration, some of the spexplorers
studying seaside ecosystems came across a gargantuan rotting hulk that had been washed ashore. It 18 meters long and was easily recognized as a
lizardwhale, but as the spexplorers lacked the appropriate equipment to transport that tonnage of meat, and the carcass was in such an advanced state of
decomposition that a further analysis was impossible to make at the time. The remains were hastily measured and photographed, and later some of the
skeletal remains were retrieved. These fragments became the holotype specimen of Nodens incredibilis.
Later, several other Nodens skeletons were discovered, and the largest of these, consisting of little more than a skull measuring over 4 meters long, lead to an
estimate of the adult size of Nodens, some 20 meters long, making it longest known marine vertebrate on Spec. It still took some time before the first verified
eyewitness sighting of a living specimen, but through a lucky coincidence, a group of marine biologists happened to be near a Nodens mating area, and
managed to film the animals both above and under water.
The film revealed that much of the forequarters of the giant lizardwhales were covered in curious looking scars, some resembling those left by giant squid
tentacles on sperm whales and others more unusual in appearance. It was deduced that the main diet of Nodens consisted of giant cephalopods, but the
peculiar scars lead to some dispute over what had caused them. Some claimed the lesions were bitemarks of some kind, while others blamed the infamous
great ktulu, which was reported as having feeding tentacles ending in handlike extensions covered in wicked hooks. A photograph of a large Nodens
individual with a severed end of a tentacle ending in just such fingerlike extensions still stuck on its skin only helped to fuel the controversy.
While the actual hunting and feeding of Nodens is yet to be observed, we do know that they are solitary most of the year and find their prey in the murky
depths of the ocean teeming with myriads of exotic cephalopod species. These saurocetes seem to fill the niche of HE sperm whales, although we can only
speculate at the differences in their hunting strategies. Despite having eyes not much larger than a human head, they are known to have a keen vision
especially in the dark. It is worth noting that Nodens are much more likely to move close to the surface at night than during the day.
While Nodens seemingly has a lot in common with mosarks, the latest analysis places it closest to nauticratisaurs. Though reports of Nodens individuals
longer than 20,5 meters are unverified, it still holds the record of the largest known mosasaur, being more massive (though not quite as long) as the leviathan.
Longtailed lizardwhales are a common species that form large schools off the western
coast of North America. They feed on a variety of small fish and cephalopods.
(fig. 13) Longtailed lizardwhale Naucratisaurus gracilis (Pacific)
A
close relative of the longtailed lizardwhale, the 45 meter long
azure lizardwhale forms large pods off the in the warm waters of the
Gulf Stream.
(fig. 14) Azure lizardwhale Naucratisaurus atlanticus (Atlantic)
The saurocetacines, on the other hand, are the more streamlined lizardwhales. Some possess long snouts and closely resemble the ichthyosaurs of Earth's
past and the dolphins of our home timeline.
One of the larger saurocetaceans, the prownose lizardwhale usually lives
alone but feeding aggregations of over 50 have been sighted. There are no
teeth in the upper jaw while 1214 conical teeth of each side of the dentary.
The prownose lizardwhale feeds primarily on cehalopods, including huge
barrelfish.
(fig. 15) Prownose lizardwhale Saurocetaceus pelagios (worldwide)
This cephalopodhunting saurocetacean lives in the Indian
ocean. Though closely related to the prownose lizardwhale,
Choo's lizardwhales rarely grow larger than 7 meters long.
These animals greatly resemble the Mesozoic ichtyosaurs,
which at first caused some confusion among the first
explorers of Spec.
(fig. 16) Choo's lizardwhale Saurocetaceus brianchooi (Indian Ocean)
(fig. 17) Mosapoise, Phocoenalacerta nigra (Equatorial Pacific)
The mosapoise is a 3.5 meters long saurocete specialized mostly on ammonoids, crabs, shellfishes and other hardshelled marine invertebrates it crushes with
its impressive battery of teeth.
The sawsnout lizardwhale, while clearly a saurocete, does not fit in with either the mosarks or the mosapoises. Some have allied this odd creature to apep,
the Nile mosasaur, but further studies are necessary to prove such a theory.
The sawsnout lizardwhale is undoubtedly one of the weirdest mosasaurs
in existence. Its upper jaw is disproportionally long and armed with
sharp outwardspointing teeth. Sawsnout lizardwhales use this weapon
to stun fastmoving prey and to rake out buried prey from the bottom.
(fig. 18) Sawsnout lizardwhale, Pristisaurus peculiaris(Caribbean)
Brian Choo, Daniel Bensen, and Tiina Aumala
,=Anguillacertidae=Anguillacerta sinensis (Yangtze mosasaur)
=Mosasauridae=|
| ,=Archaeosaurocetacidae=Apep aegyptianus (Nile Mosasaur)
`=|
| ,=Gigantoserpentidae=Gigantoserpens microdon (Hobb's leviathan)
| |
| | ,=Pristrix monstrum Mosark
| | ,=|
| | | | ,=C. atrox (Zahn)
| | | `=Carcharosaurus=|
| | | | ,=C. crassus (Chubby mosark)
| | | `=|
| | | `=C. velox (Sakhala)
| | ,=|
| | | |=? Nodens incredibilis (Nodens)
| | | |
| | | | ,=N. gracilis (Longtailed lizardwhale)
| | | `=Naucratisaurus=|
| | | `=N. atlanticus (Azure lizardwhale)
| | ,=|
| | | | ,=S. pelagios (Prownose lizardwhale)
| | | | ,=Saurocetaceus=|
| | | | | `=S. brianchooi (Choo's lizardwhale)
| | | `=|
| | | `=Phocoenalacerta nigra (Mosapoise)
`=Saurocetaciodea=| |
`=Saurocetacidae=|
`=Pristisaurus peculiaris (Sawsnout lizardwhale)
Back
Mosasaurs (clade Mosasauridae) evolved during the late Mesozoic when a group of monitorlike lizards entered the ocean. These toothy, serpentine
predators might have seemed chunky and illmade when compared to the other marine predators of the time. However, while the ichthyosaurs went extinct
before the end of the Cretaceous and the plesiosaurs soon after, the mosasaurs have gone on to become one of the largest and most diverse clades of marine
vertebrates.
Most presentday mosasaurs are quite unlike their serpentine forebears. Whatever environmental catastrophe that mauled the archaeocetaceans in our world
almost had the same effect on the Late Eocene mosasaurs. Gone were the huge, 15m long tylosaurine seaserpents and their kin, never to return.
ANGUILLACERTIDAE (TiLung)
Years after specbiologists had concluded that none of the ancestral, longbodied mosasaurs
survived to the present day, the illustrious Tiina Aumala proved the existence of Anguillacerta
sinensis, the tilung.
(fig. 1) Yangtze mosasaur, Anguillacerta sinensis (Central and southern Asia)
Anguillacerta possesses nostrils placed above the eyes, as in the saurocetes, but its body is long, the tail is laterally flattened and possesses no fluke, and the
hind limbs are missing altogether. This cryptic piscivore is clearly a mosasaur, but is only distantly related to the saurocetes and is loosely allied with the
archaic forms that supposedly died out at the end of the Eocene.
ARCHAEOSAUROCETACIDAE (Apeps)
The earlyEocene radiation that produced the eellike river mosasaurs also resulted in the birth of the saurocetes, the most common of the extant mosasaur
groups. The first saurocetes, from the Eocene, are similar to modern forms, but fossil impressions show that they did not possess the paired tailfluke of the
advanced lizardwhales. Only a single species remains of this once mighty group.
The apep is a piscivorous aquatic lizard that today seems to be restricted to the
river Nile. Apeps can reach the length of 4.5 meters, though such venerable
individuals are rarely seen, and 23 meter long mosasaurs are more common.
(fig. 2) Apep, Apep aegypianus (Northern Africa)
Though at first the apep seems to resemble the serpentine longbodied yangtze mosasaur, it is acutally the last remaining archaeosaurocetid, or ansestral
saurocete, closely resembling fossil species such as Balaenanguis. Based on the patchy fossil record, genus Apep seems to date back at least to the
Oligocene (and possibly the Eocene) and has barely changed at all after it first appeared.
GIGANTOSERPENTIDAE (Leviathans)
The first evidence of one of Spec's most enigmatic seagiants washed up on a stony beach in eastern Africa after a particularly stormy night. The discoverer,
a certain Calvin Hobb, was apparently walking dangerously near the choppy shore when a sudden, violent surge practically dumped the specimen at his feet.
It was a cylindrical mass of rotting flesh over twelve metres in length. Within one end of the carcass, researchers recovered the twometre long skull minus the
lower jaw, the vertebral column up to the 17th dorsal and parts of right forepaddle. An examination of the bones made it clear that the carcass, now dubbed
"Hobb's Leviathan" represented a new species of mosasaur, but of what kind? Popular initial reports claimed that it represented a "living fossil", an archaic
longbodied mosasaurid that had escaped the Eocene extinction. More cautious researchers noted apparent similarities with the needlelike teeth and gracile
bodyform of the Yangtze mosasaur, suggesting a relationship with anguillacertids. Regardless of where it fitted amongst the Mosasauria, the skull and
vertebrae were sufficient cause to warrant it's description as a new species Gigantoserpens microdon, "the teenytoothed gigantic serpent"
(fig. 3) Early reconstruction of Hobb's Leviathan done prior to its description. Illustration by Tiina Aumala
Despite the incompleteness of the remains, the idea of a giant seaserpent was irresistable and a number of popular reconstructions depicted the
animal as an vast eellike creature with a stated length of over 25 metres. Soon sightings of giant killer serpents began cropping up everywhere
from the Caribbean to the bottom of Tiina's beer stein. Hoaxes pertaining to leviathanrelated fatalities at sea soon led to much hysteria. Nothing
more was heard from the real Gigantoserpens for over three years until a vessel surveying the west coast of South America produced blurry
photographs of a huge sea creature near San Ambrosio. They appeared to show nothing less than a supposedly extinct longnecked plesiosaur,
an animal that seemed to possess a small head, longneck and a bulbous, flippered body. An expedition to learn more of this creature was
hastily dispatched and it was soon ascertained that these "plesiosaurs" were in fact the real Hobb's leviathans.
The true appearance of these giant mosasaurs was completely
unexpected and nothing like the snakelike hypothetical
reconstructions. Instead of a vicious predator, the real leviathan
proved to be a sluggish, passive hunter of small prey. Rather than a
relic of the Eocene or some giant oceangoing rivermosasaur,
Gigantoserpens turned out to be a highly aberrant truesaurocetean
although different enough to be placed, along with subsequently
discovered Pliocene fossil forms, into a new clade the
Gigantoserpentidae.
(fig. 4)A living Gigantoserpens photographed off the west coast of South America. At "only" 11 metres in length, this is a relatively small individual.
HOBB'S LEVIATHAN DESCRIBED
(fig. 5)Skeletal silhouette of Hobb's leviathan alongside the incomplete holotype specimen and a human diver (diver courtesy Tiina Aumala)
Gigantoserpens is a bizarre saurocetacean that can reach a length of 21 metres and weigh in at an estimated 60 tonnes making it by far the
largest known squamate. The head is comparatively small and flat, sitting on a very short neck behind which sprout a pair of small flippers.
These are often held against the neck and can be difficult to discern from a distance.
The anterior dorsal vertebrae are lightweight while the associated ribs are greatly reduced in size. Thus in life, the forequarters of the animal
appear slender and snakelike, creating the illusion of an elongated neck. Further down the trunk the vertebrae become drastically larger and
more robust while the length and girth of the ribs increases causing the body to balloon out. The pelvic girdle and hindflippers are incredibly
large by mosasaur standards whilst the tail is exceptionally long and deep with prominant lateral keels, terminating in a huge caudalfin. A low,
triangular dorsal fin is located midway along the tail.
The dentition consists of numerous fine needlelike teeth and the lower jaw is loosely attached to the skull
allowing for a very wide gape. The interior of the mouth contains a series of rugosities called gnathochromes
which are infested with growths of luminescent bacteria that are clearly visible when the jaws are opened.
(fig. 6) (left) Frontal view of open mouth showing gnathochromes rugosities on which grow clusters of luminescent bacteria. The pterygoid teeth have been reduced to a
small row of nodules that are not externally visible on large adults. (right) Appearance of glowing gnathochromes in dark water. The precise arrangement varies between
individuals.
(fig. 7)Near the Azores, a Hobb's leviathan disappears in a great cloud of poo.
One unusual internal feature is a large sac on the lower intestine that can be filled with over 90 litres of reddishbrown syrupy faecal matter. When threatened
by a large carnivore, this liquid is expelled in a great, dense cloud that confuses or repels the attacker and gives the slowmoving leviathan the chance of
escape. A similar strategy is used (on a much smaller scale) by the HomeEarth pygmy sperm whales of the family Kogiidae.
The leviathan is primarily a mesopelagic predator that has been characterised as a "mosasaur trying to be an elasmosaur". Based on the stomach contents of
stranded individuals, it mostly feeds on nonshelly pelagic prey of up to a metre in length. It is not a choosy feeder and takes whatever happens to be
abundant in the area. While it has yet to be witnessed, it's feeding strategy probably involves cruising through the inky blackness with it's jaws agape. The
twinkling bacterial colonies in it's mouth give the impression of a swarm of bioluminescent plankton attracting shoals of fish, shrimp and squid to within easy
striking distance. The slender forequarters can curl and dart around with great speed, allowing it to snap up fasterswimming prey. The presence of injested
echinoderms and small skates suggest it also forages on the benthos, perhaps while gathering stones for ballast. One particularly scarred individual that was
recently stranded on New Caledonia was found to have a belly full of piranhakeets. The giant hindflippers are used for stability and steering, effectively filling
the role of pectoral fins on a more conventional sea creature. The stubby forepaddles seem to act as canard foreplanes, conferring a degree of hydrodynamic
stability to the anterior of the animal when on the move. While feeding, they are probably held conformally to avoid drag as the neck sweeps around.
Alternatively the forelimbs might play a role in sheperding prey although they seem a little too far from the mouth for this. Strandings and sightings indicate a
cosmopolitan species of deep offshore tropical to warm temperate seas. Although sparsely distributed, they are sometimes found in large feeding
concentrations and appear to have a habitat requirement for deep slope waters with steep depth gradients. Except for infrequent forays to the surface for air,
they follow the vertical migration of their prey, cruising at depths of over 900m during the day before rising to within 100m of the surface at night. Much
remains to be discovered about these remarkable giants and as yet we know nothing of their seasonal migrations, reproduction and development.
SAUROCETACIDAE (Mosarks and lizardwhales)
(fig. 8) A sampling of saurocetacidae (with apep)
1. Prownose lizardwhale
2. Apep
3. Zahn
4. Mosapoise
5. Mosark
6. Sawsnout lizardwhale
7. Longtailed lizardwhale
8. Sakhala
Currently the most highly specialized of marine reptiles, saurocetes do not bear much resemblance to their seaserpent ancestors, and rather resemble the
dolphins and whales of RL. Like the Jurassic ichthyosaurs before them and the odontocetaceans of our Earth, the ancestors of these creatures were long
bodied serpentine inshore predators (see above) that developed an increasingly fishlike body for a pelagic existence.
Saurocetes are fishlike marine squamates ranging from 1.5 to 15 metres in length. They are broadly analogous with our world's odontocetes but have not
produced a biggame carnivore in the same league as the orca. The scales have been completely lost and have been replaced with a smooth, leathery hide.
The paired nostrils are positioned at the top of the head. Propulsion is by strokes of a fishlike tail bearing 2 vertical flukes. All saurocetes are viviparous.
The precursors of the saurocetaceans were the huge predatory mosasaurs, marine squamates that evolved in the Cretaceous and were amongst the top
ocean predators from the Santonian to the Eocene. The decline of inland seas in the Maastrichtian put pressure on the mosasaurs to more fully exploit the
open oceans. One lineage abandoned the serpentine mosasaurbody, becoming more fishlike with a large falcate caudal fin replacing the simple spatulate
form.
While the Late Eocene disaster decimated their longbodied kin, the early saurocetaceans flourished, developing ever larger and larger forms. Today over 40
species ply the tropical to warm temperate oceans of the world, feeding mainly on cephalopods and small fish. However, they have been unable to venture
into the cooler sea. Those rich, polar killing grounds are the domains of warmblooded predators: birds like seaguins and penguins, and mammals like
walduks.
While HomeEarth's cetaceans cover a wide range of body types (from dolphins to whales), sarurocetes do not display so wide a diversity. There are no
filterfeeding mosasaurs, and the disparity between large and small species is relatively minimal. However, clear distinctions within Saurocetacidae do exist.
The carcharosaurines, or mosarks, are powerfullybuilt predators. Some, like the zahn, are truly enormous.
The mosark, cousin of the sakhala and zahn, is a 810 m long
predator of temperate oceans around the world. A mediumsized
pelagic predator, the mosark gained its name mainly from its shark
like appearance and behaviour, and many of its relatives are also often
unofficially referred to as mosarks for the same reason.
(fig. 9) Mosark, Pristrix monstrum (worldwide)
This lizardwhale is in many respects similiar to the zahn, though smaller and swifter. Though their diet mostly consists of cephalopods and fish, mosarks are
also known to attack small lizardwhales and other marine vertebrates.
The zahn is one of the largest lizardwhales. This 14 m
long solitary predator is large enough to swallow small
wingsquid whole and tear fully grown mantasquid into
pieces. Zhans attack just about anything big enough to
fit between their enormous jaws, including seabirds,
rays, sharks, swimming or wading dinosaurs, other
lizardwhales and inflatable boats filled with marine
biologists. There have been at least two unfortunate
incidents where Spec scientists have nearly ended up
in a zahn's bellythey were apparently saved only by
the foul taste of the boat. After that, small rubber
boats haven't been used in zahninfested waters.
(fig. 10) Zahn, Carcharosaurus atrox (Equatorial)
(fig. 11) Chubby mosark, Carcharosaurus crassus (Western Atlantic)
Warmed by the Gulf Stream, the waters off the coast of eastern North America are home to many predators, from walduks to sharks, but the most feared of
all is the chubby mosark. These odd little mosasaurs dart around the shallows from Florida to Newfoundland, snatching up anything that moves.
Despite its common name, the chubby mosark is only distantly related to the true mosarks (genus Pristrix). These creatures, are, in fact, close kin to the
zahns, massive, orcalike predators that hunt upper levels of the deep ocean. The chubby mosark, on the other hand, is one of several Carcharosaurus
lineages that have adapted for a life hunting the nutrientrich shallows of the continental shelves. These hunters are small, and rely upon their sensitive
Jacobson's organs to taste the water and home in on prey, rather than the easily confused eye. As a result, the eyes of the chubby mosark are rather small
and not very sensitive, while their chemical sense is superb.
Another way in which the chubby mosarks distinguish themselves is in their geographical range, which extends further north than any other marine mosasaur.
Although they winter in the warm waters off the coast of Florida, chubby mosasaurs spend the summer months rearing their pups in the Gulf of St. Lawrence.
This behavior is quite useful, since the habitat is devoid of competing mosasaurs, and the native pods of selkies make a tasty snack for the larger reptiles.
However, the northern water, although made bearable by the Gulf Stream, are still frigid to the coldblooded mosasaurs, and so chubby mosarks must
produce internal "coats" of insulating blubber, the source of their name.
(fig. 12) Sakhala, Carcharosaurus velox (Great Barrier Reef)
The Sakhala is a small (3 m long) and swift sharklike mosasaur that lives in the Great Barrier Reef. Though it mainly eats small fish and cephalopods, it may
attack anything smaller than a meter across if it looks edible.
(fig. 13) Nodens, Nodens incredibilis (Great Barrier Reef)
Ironically the largest known saurocete was not first discovered in the sea, but on dry land. During the first years of spexploration, some of the spexplorers
studying seaside ecosystems came across a gargantuan rotting hulk that had been washed ashore. It 18 meters long and was easily recognized as a
lizardwhale, but as the spexplorers lacked the appropriate equipment to transport that tonnage of meat, and the carcass was in such an advanced state of
decomposition that a further analysis was impossible to make at the time. The remains were hastily measured and photographed, and later some of the
skeletal remains were retrieved. These fragments became the holotype specimen of Nodens incredibilis.
Later, several other Nodens skeletons were discovered, and the largest of these, consisting of little more than a skull measuring over 4 meters long, lead to an
estimate of the adult size of Nodens, some 20 meters long, making it longest known marine vertebrate on Spec. It still took some time before the first verified
eyewitness sighting of a living specimen, but through a lucky coincidence, a group of marine biologists happened to be near a Nodens mating area, and
managed to film the animals both above and under water.
The film revealed that much of the forequarters of the giant lizardwhales were covered in curious looking scars, some resembling those left by giant squid
tentacles on sperm whales and others more unusual in appearance. It was deduced that the main diet of Nodens consisted of giant cephalopods, but the
peculiar scars lead to some dispute over what had caused them. Some claimed the lesions were bitemarks of some kind, while others blamed the infamous
great ktulu, which was reported as having feeding tentacles ending in handlike extensions covered in wicked hooks. A photograph of a large Nodens
individual with a severed end of a tentacle ending in just such fingerlike extensions still stuck on its skin only helped to fuel the controversy.
While the actual hunting and feeding of Nodens is yet to be observed, we do know that they are solitary most of the year and find their prey in the murky
depths of the ocean teeming with myriads of exotic cephalopod species. These saurocetes seem to fill the niche of HE sperm whales, although we can only
speculate at the differences in their hunting strategies. Despite having eyes not much larger than a human head, they are known to have a keen vision
especially in the dark. It is worth noting that Nodens are much more likely to move close to the surface at night than during the day.
While Nodens seemingly has a lot in common with mosarks, the latest analysis places it closest to nauticratisaurs. Though reports of Nodens individuals
longer than 20,5 meters are unverified, it still holds the record of the largest known mosasaur, being more massive (though not quite as long) as the leviathan.
Longtailed lizardwhales are a common species that form large schools off the western
coast of North America. They feed on a variety of small fish and cephalopods.
(fig. 13) Longtailed lizardwhale Naucratisaurus gracilis (Pacific)
A
close relative of the longtailed lizardwhale, the 45 meter long
azure lizardwhale forms large pods off the in the warm waters of the
Gulf Stream.
(fig. 14) Azure lizardwhale Naucratisaurus atlanticus (Atlantic)
The saurocetacines, on the other hand, are the more streamlined lizardwhales. Some possess long snouts and closely resemble the ichthyosaurs of Earth's
past and the dolphins of our home timeline.
One of the larger saurocetaceans, the prownose lizardwhale usually lives
alone but feeding aggregations of over 50 have been sighted. There are no
teeth in the upper jaw while 1214 conical teeth of each side of the dentary.
The prownose lizardwhale feeds primarily on cehalopods, including huge
barrelfish.
(fig. 15) Prownose lizardwhale Saurocetaceus pelagios (worldwide)
This cephalopodhunting saurocetacean lives in the Indian
ocean. Though closely related to the prownose lizardwhale,
Choo's lizardwhales rarely grow larger than 7 meters long.
These animals greatly resemble the Mesozoic ichtyosaurs,
which at first caused some confusion among the first
explorers of Spec.
(fig. 16) Choo's lizardwhale Saurocetaceus brianchooi (Indian Ocean)
(fig. 17) Mosapoise, Phocoenalacerta nigra (Equatorial Pacific)
The mosapoise is a 3.5 meters long saurocete specialized mostly on ammonoids, crabs, shellfishes and other hardshelled marine invertebrates it crushes with
its impressive battery of teeth.
The sawsnout lizardwhale, while clearly a saurocete, does not fit in with either the mosarks or the mosapoises. Some have allied this odd creature to apep,
the Nile mosasaur, but further studies are necessary to prove such a theory.
The sawsnout lizardwhale is undoubtedly one of the weirdest mosasaurs
in existence. Its upper jaw is disproportionally long and armed with
sharp outwardspointing teeth. Sawsnout lizardwhales use this weapon
to stun fastmoving prey and to rake out buried prey from the bottom.
(fig. 18) Sawsnout lizardwhale, Pristisaurus peculiaris(Caribbean)
Brian Choo, Daniel Bensen, and Tiina Aumala
,=Anguillacertidae=Anguillacerta sinensis (Yangtze mosasaur)
=Mosasauridae=|
| ,=Archaeosaurocetacidae=Apep aegyptianus (Nile Mosasaur)
`=|
| ,=Gigantoserpentidae=Gigantoserpens microdon (Hobb's leviathan)
| |
| | ,=Pristrix monstrum Mosark
| | ,=|
| | | | ,=C. atrox (Zahn)
| | | `=Carcharosaurus=|
| | | | ,=C. crassus (Chubby mosark)
| | | `=|
| | | `=C. velox (Sakhala)
| | ,=|
| | | |=? Nodens incredibilis (Nodens)
| | | |
| | | | ,=N. gracilis (Longtailed lizardwhale)
| | | `=Naucratisaurus=|
| | | `=N. atlanticus (Azure lizardwhale)
| | ,=|
| | | | ,=S. pelagios (Prownose lizardwhale)
| | | | ,=Saurocetaceus=|
| | | | | `=S. brianchooi (Choo's lizardwhale)
| | | `=|
| | | `=Phocoenalacerta nigra (Mosapoise)
`=Saurocetaciodea=| |
`=Saurocetacidae=|
`=Pristisaurus peculiaris (Sawsnout lizardwhale)
Back
Mosasaurs (clade Mosasauridae) evolved during the late Mesozoic when a group of monitorlike lizards entered the ocean. These toothy, serpentine
predators might have seemed chunky and illmade when compared to the other marine predators of the time. However, while the ichthyosaurs went extinct
before the end of the Cretaceous and the plesiosaurs soon after, the mosasaurs have gone on to become one of the largest and most diverse clades of marine
vertebrates.
Most presentday mosasaurs are quite unlike their serpentine forebears. Whatever environmental catastrophe that mauled the archaeocetaceans in our world
almost had the same effect on the Late Eocene mosasaurs. Gone were the huge, 15m long tylosaurine seaserpents and their kin, never to return.
ANGUILLACERTIDAE (TiLung)
Years after specbiologists had concluded that none of the ancestral, longbodied mosasaurs
survived to the present day, the illustrious Tiina Aumala proved the existence of Anguillacerta
sinensis, the tilung.
(fig. 1) Yangtze mosasaur, Anguillacerta sinensis (Central and southern Asia)
Anguillacerta possesses nostrils placed above the eyes, as in the saurocetes, but its body is long, the tail is laterally flattened and possesses no fluke, and the
hind limbs are missing altogether. This cryptic piscivore is clearly a mosasaur, but is only distantly related to the saurocetes and is loosely allied with the
archaic forms that supposedly died out at the end of the Eocene.
ARCHAEOSAUROCETACIDAE (Apeps)
The earlyEocene radiation that produced the eellike river mosasaurs also resulted in the birth of the saurocetes, the most common of the extant mosasaur
groups. The first saurocetes, from the Eocene, are similar to modern forms, but fossil impressions show that they did not possess the paired tailfluke of the
advanced lizardwhales. Only a single species remains of this once mighty group.
The apep is a piscivorous aquatic lizard that today seems to be restricted to the
river Nile. Apeps can reach the length of 4.5 meters, though such venerable
individuals are rarely seen, and 23 meter long mosasaurs are more common.
(fig. 2) Apep, Apep aegypianus (Northern Africa)
Though at first the apep seems to resemble the serpentine longbodied yangtze mosasaur, it is acutally the last remaining archaeosaurocetid, or ansestral
saurocete, closely resembling fossil species such as Balaenanguis. Based on the patchy fossil record, genus Apep seems to date back at least to the
Oligocene (and possibly the Eocene) and has barely changed at all after it first appeared.
GIGANTOSERPENTIDAE (Leviathans)
The first evidence of one of Spec's most enigmatic seagiants washed up on a stony beach in eastern Africa after a particularly stormy night. The discoverer,
a certain Calvin Hobb, was apparently walking dangerously near the choppy shore when a sudden, violent surge practically dumped the specimen at his feet.
It was a cylindrical mass of rotting flesh over twelve metres in length. Within one end of the carcass, researchers recovered the twometre long skull minus the
lower jaw, the vertebral column up to the 17th dorsal and parts of right forepaddle. An examination of the bones made it clear that the carcass, now dubbed
"Hobb's Leviathan" represented a new species of mosasaur, but of what kind? Popular initial reports claimed that it represented a "living fossil", an archaic
longbodied mosasaurid that had escaped the Eocene extinction. More cautious researchers noted apparent similarities with the needlelike teeth and gracile
bodyform of the Yangtze mosasaur, suggesting a relationship with anguillacertids. Regardless of where it fitted amongst the Mosasauria, the skull and
vertebrae were sufficient cause to warrant it's description as a new species Gigantoserpens microdon, "the teenytoothed gigantic serpent"
(fig. 3) Early reconstruction of Hobb's Leviathan done prior to its description. Illustration by Tiina Aumala
Despite the incompleteness of the remains, the idea of a giant seaserpent was irresistable and a number of popular reconstructions depicted the
animal as an vast eellike creature with a stated length of over 25 metres. Soon sightings of giant killer serpents began cropping up everywhere
from the Caribbean to the bottom of Tiina's beer stein. Hoaxes pertaining to leviathanrelated fatalities at sea soon led to much hysteria. Nothing
more was heard from the real Gigantoserpens for over three years until a vessel surveying the west coast of South America produced blurry
photographs of a huge sea creature near San Ambrosio. They appeared to show nothing less than a supposedly extinct longnecked plesiosaur,
an animal that seemed to possess a small head, longneck and a bulbous, flippered body. An expedition to learn more of this creature was
hastily dispatched and it was soon ascertained that these "plesiosaurs" were in fact the real Hobb's leviathans.
The true appearance of these giant mosasaurs was completely
unexpected and nothing like the snakelike hypothetical
reconstructions. Instead of a vicious predator, the real leviathan
proved to be a sluggish, passive hunter of small prey. Rather than a
relic of the Eocene or some giant oceangoing rivermosasaur,
Gigantoserpens turned out to be a highly aberrant truesaurocetean
although different enough to be placed, along with subsequently
discovered Pliocene fossil forms, into a new clade the
Gigantoserpentidae.
(fig. 4)A living Gigantoserpens photographed off the west coast of South America. At "only" 11 metres in length, this is a relatively small individual.
HOBB'S LEVIATHAN DESCRIBED
(fig. 5)Skeletal silhouette of Hobb's leviathan alongside the incomplete holotype specimen and a human diver (diver courtesy Tiina Aumala)
Gigantoserpens is a bizarre saurocetacean that can reach a length of 21 metres and weigh in at an estimated 60 tonnes making it by far the
largest known squamate. The head is comparatively small and flat, sitting on a very short neck behind which sprout a pair of small flippers.
These are often held against the neck and can be difficult to discern from a distance.
The anterior dorsal vertebrae are lightweight while the associated ribs are greatly reduced in size. Thus in life, the forequarters of the animal
appear slender and snakelike, creating the illusion of an elongated neck. Further down the trunk the vertebrae become drastically larger and
more robust while the length and girth of the ribs increases causing the body to balloon out. The pelvic girdle and hindflippers are incredibly
large by mosasaur standards whilst the tail is exceptionally long and deep with prominant lateral keels, terminating in a huge caudalfin. A low,
triangular dorsal fin is located midway along the tail.
The dentition consists of numerous fine needlelike teeth and the lower jaw is loosely attached to the skull
allowing for a very wide gape. The interior of the mouth contains a series of rugosities called gnathochromes
which are infested with growths of luminescent bacteria that are clearly visible when the jaws are opened.
(fig. 6) (left) Frontal view of open mouth showing gnathochromes rugosities on which grow clusters of luminescent bacteria. The pterygoid teeth have been reduced to a
small row of nodules that are not externally visible on large adults. (right) Appearance of glowing gnathochromes in dark water. The precise arrangement varies between
individuals.
(fig. 7)Near the Azores, a Hobb's leviathan disappears in a great cloud of poo.
One unusual internal feature is a large sac on the lower intestine that can be filled with over 90 litres of reddishbrown syrupy faecal matter. When threatened
by a large carnivore, this liquid is expelled in a great, dense cloud that confuses or repels the attacker and gives the slowmoving leviathan the chance of
escape. A similar strategy is used (on a much smaller scale) by the HomeEarth pygmy sperm whales of the family Kogiidae.
The leviathan is primarily a mesopelagic predator that has been characterised as a "mosasaur trying to be an elasmosaur". Based on the stomach contents of
stranded individuals, it mostly feeds on nonshelly pelagic prey of up to a metre in length. It is not a choosy feeder and takes whatever happens to be
abundant in the area. While it has yet to be witnessed, it's feeding strategy probably involves cruising through the inky blackness with it's jaws agape. The
twinkling bacterial colonies in it's mouth give the impression of a swarm of bioluminescent plankton attracting shoals of fish, shrimp and squid to within easy
striking distance. The slender forequarters can curl and dart around with great speed, allowing it to snap up fasterswimming prey. The presence of injested
echinoderms and small skates suggest it also forages on the benthos, perhaps while gathering stones for ballast. One particularly scarred individual that was
recently stranded on New Caledonia was found to have a belly full of piranhakeets. The giant hindflippers are used for stability and steering, effectively filling
the role of pectoral fins on a more conventional sea creature. The stubby forepaddles seem to act as canard foreplanes, conferring a degree of hydrodynamic
stability to the anterior of the animal when on the move. While feeding, they are probably held conformally to avoid drag as the neck sweeps around.
Alternatively the forelimbs might play a role in sheperding prey although they seem a little too far from the mouth for this. Strandings and sightings indicate a
cosmopolitan species of deep offshore tropical to warm temperate seas. Although sparsely distributed, they are sometimes found in large feeding
concentrations and appear to have a habitat requirement for deep slope waters with steep depth gradients. Except for infrequent forays to the surface for air,
they follow the vertical migration of their prey, cruising at depths of over 900m during the day before rising to within 100m of the surface at night. Much
remains to be discovered about these remarkable giants and as yet we know nothing of their seasonal migrations, reproduction and development.
SAUROCETACIDAE (Mosarks and lizardwhales)
(fig. 8) A sampling of saurocetacidae (with apep)
1. Prownose lizardwhale
2. Apep
3. Zahn
4. Mosapoise
5. Mosark
6. Sawsnout lizardwhale
7. Longtailed lizardwhale
8. Sakhala
Currently the most highly specialized of marine reptiles, saurocetes do not bear much resemblance to their seaserpent ancestors, and rather resemble the
dolphins and whales of RL. Like the Jurassic ichthyosaurs before them and the odontocetaceans of our Earth, the ancestors of these creatures were long
bodied serpentine inshore predators (see above) that developed an increasingly fishlike body for a pelagic existence.
Saurocetes are fishlike marine squamates ranging from 1.5 to 15 metres in length. They are broadly analogous with our world's odontocetes but have not
produced a biggame carnivore in the same league as the orca. The scales have been completely lost and have been replaced with a smooth, leathery hide.
The paired nostrils are positioned at the top of the head. Propulsion is by strokes of a fishlike tail bearing 2 vertical flukes. All saurocetes are viviparous.
The precursors of the saurocetaceans were the huge predatory mosasaurs, marine squamates that evolved in the Cretaceous and were amongst the top
ocean predators from the Santonian to the Eocene. The decline of inland seas in the Maastrichtian put pressure on the mosasaurs to more fully exploit the
open oceans. One lineage abandoned the serpentine mosasaurbody, becoming more fishlike with a large falcate caudal fin replacing the simple spatulate
form.
While the Late Eocene disaster decimated their longbodied kin, the early saurocetaceans flourished, developing ever larger and larger forms. Today over 40
species ply the tropical to warm temperate oceans of the world, feeding mainly on cephalopods and small fish. However, they have been unable to venture
into the cooler sea. Those rich, polar killing grounds are the domains of warmblooded predators: birds like seaguins and penguins, and mammals like
walduks.
While HomeEarth's cetaceans cover a wide range of body types (from dolphins to whales), sarurocetes do not display so wide a diversity. There are no
filterfeeding mosasaurs, and the disparity between large and small species is relatively minimal. However, clear distinctions within Saurocetacidae do exist.
The carcharosaurines, or mosarks, are powerfullybuilt predators. Some, like the zahn, are truly enormous.
The mosark, cousin of the sakhala and zahn, is a 810 m long
predator of temperate oceans around the world. A mediumsized
pelagic predator, the mosark gained its name mainly from its shark
like appearance and behaviour, and many of its relatives are also often
unofficially referred to as mosarks for the same reason.
(fig. 9) Mosark, Pristrix monstrum (worldwide)
This lizardwhale is in many respects similiar to the zahn, though smaller and swifter. Though their diet mostly consists of cephalopods and fish, mosarks are
also known to attack small lizardwhales and other marine vertebrates.
The zahn is one of the largest lizardwhales. This 14 m
long solitary predator is large enough to swallow small
wingsquid whole and tear fully grown mantasquid into
pieces. Zhans attack just about anything big enough to
fit between their enormous jaws, including seabirds,
rays, sharks, swimming or wading dinosaurs, other
lizardwhales and inflatable boats filled with marine
biologists. There have been at least two unfortunate
incidents where Spec scientists have nearly ended up
in a zahn's bellythey were apparently saved only by
the foul taste of the boat. After that, small rubber
boats haven't been used in zahninfested waters.
(fig. 10) Zahn, Carcharosaurus atrox (Equatorial)
(fig. 11) Chubby mosark, Carcharosaurus crassus (Western Atlantic)
Warmed by the Gulf Stream, the waters off the coast of eastern North America are home to many predators, from walduks to sharks, but the most feared of
all is the chubby mosark. These odd little mosasaurs dart around the shallows from Florida to Newfoundland, snatching up anything that moves.
Despite its common name, the chubby mosark is only distantly related to the true mosarks (genus Pristrix). These creatures, are, in fact, close kin to the
zahns, massive, orcalike predators that hunt upper levels of the deep ocean. The chubby mosark, on the other hand, is one of several Carcharosaurus
lineages that have adapted for a life hunting the nutrientrich shallows of the continental shelves. These hunters are small, and rely upon their sensitive
Jacobson's organs to taste the water and home in on prey, rather than the easily confused eye. As a result, the eyes of the chubby mosark are rather small
and not very sensitive, while their chemical sense is superb.
Another way in which the chubby mosarks distinguish themselves is in their geographical range, which extends further north than any other marine mosasaur.
Although they winter in the warm waters off the coast of Florida, chubby mosasaurs spend the summer months rearing their pups in the Gulf of St. Lawrence.
This behavior is quite useful, since the habitat is devoid of competing mosasaurs, and the native pods of selkies make a tasty snack for the larger reptiles.
However, the northern water, although made bearable by the Gulf Stream, are still frigid to the coldblooded mosasaurs, and so chubby mosarks must
produce internal "coats" of insulating blubber, the source of their name.
(fig. 12) Sakhala, Carcharosaurus velox (Great Barrier Reef)
The Sakhala is a small (3 m long) and swift sharklike mosasaur that lives in the Great Barrier Reef. Though it mainly eats small fish and cephalopods, it may
attack anything smaller than a meter across if it looks edible.
(fig. 13) Nodens, Nodens incredibilis (Great Barrier Reef)
Ironically the largest known saurocete was not first discovered in the sea, but on dry land. During the first years of spexploration, some of the spexplorers
studying seaside ecosystems came across a gargantuan rotting hulk that had been washed ashore. It 18 meters long and was easily recognized as a
lizardwhale, but as the spexplorers lacked the appropriate equipment to transport that tonnage of meat, and the carcass was in such an advanced state of
decomposition that a further analysis was impossible to make at the time. The remains were hastily measured and photographed, and later some of the
skeletal remains were retrieved. These fragments became the holotype specimen of Nodens incredibilis.
Later, several other Nodens skeletons were discovered, and the largest of these, consisting of little more than a skull measuring over 4 meters long, lead to an
estimate of the adult size of Nodens, some 20 meters long, making it longest known marine vertebrate on Spec. It still took some time before the first verified
eyewitness sighting of a living specimen, but through a lucky coincidence, a group of marine biologists happened to be near a Nodens mating area, and
managed to film the animals both above and under water.
The film revealed that much of the forequarters of the giant lizardwhales were covered in curious looking scars, some resembling those left by giant squid
tentacles on sperm whales and others more unusual in appearance. It was deduced that the main diet of Nodens consisted of giant cephalopods, but the
peculiar scars lead to some dispute over what had caused them. Some claimed the lesions were bitemarks of some kind, while others blamed the infamous
great ktulu, which was reported as having feeding tentacles ending in handlike extensions covered in wicked hooks. A photograph of a large Nodens
individual with a severed end of a tentacle ending in just such fingerlike extensions still stuck on its skin only helped to fuel the controversy.
While the actual hunting and feeding of Nodens is yet to be observed, we do know that they are solitary most of the year and find their prey in the murky
depths of the ocean teeming with myriads of exotic cephalopod species. These saurocetes seem to fill the niche of HE sperm whales, although we can only
speculate at the differences in their hunting strategies. Despite having eyes not much larger than a human head, they are known to have a keen vision
especially in the dark. It is worth noting that Nodens are much more likely to move close to the surface at night than during the day.
While Nodens seemingly has a lot in common with mosarks, the latest analysis places it closest to nauticratisaurs. Though reports of Nodens individuals
longer than 20,5 meters are unverified, it still holds the record of the largest known mosasaur, being more massive (though not quite as long) as the leviathan.
Longtailed lizardwhales are a common species that form large schools off the western
coast of North America. They feed on a variety of small fish and cephalopods.
(fig. 13) Longtailed lizardwhale Naucratisaurus gracilis (Pacific)
A
close relative of the longtailed lizardwhale, the 45 meter long
azure lizardwhale forms large pods off the in the warm waters of the
Gulf Stream.
(fig. 14) Azure lizardwhale Naucratisaurus atlanticus (Atlantic)
The saurocetacines, on the other hand, are the more streamlined lizardwhales. Some possess long snouts and closely resemble the ichthyosaurs of Earth's
past and the dolphins of our home timeline.
One of the larger saurocetaceans, the prownose lizardwhale usually lives
alone but feeding aggregations of over 50 have been sighted. There are no
teeth in the upper jaw while 1214 conical teeth of each side of the dentary.
The prownose lizardwhale feeds primarily on cehalopods, including huge
barrelfish.
(fig. 15) Prownose lizardwhale Saurocetaceus pelagios (worldwide)
This cephalopodhunting saurocetacean lives in the Indian
ocean. Though closely related to the prownose lizardwhale,
Choo's lizardwhales rarely grow larger than 7 meters long.
These animals greatly resemble the Mesozoic ichtyosaurs,
which at first caused some confusion among the first
explorers of Spec.
(fig. 16) Choo's lizardwhale Saurocetaceus brianchooi (Indian Ocean)
(fig. 17) Mosapoise, Phocoenalacerta nigra (Equatorial Pacific)
The mosapoise is a 3.5 meters long saurocete specialized mostly on ammonoids, crabs, shellfishes and other hardshelled marine invertebrates it crushes with
its impressive battery of teeth.
The sawsnout lizardwhale, while clearly a saurocete, does not fit in with either the mosarks or the mosapoises. Some have allied this odd creature to apep,
the Nile mosasaur, but further studies are necessary to prove such a theory.
The sawsnout lizardwhale is undoubtedly one of the weirdest mosasaurs
in existence. Its upper jaw is disproportionally long and armed with
sharp outwardspointing teeth. Sawsnout lizardwhales use this weapon
to stun fastmoving prey and to rake out buried prey from the bottom.
(fig. 18) Sawsnout lizardwhale, Pristisaurus peculiaris(Caribbean)
Brian Choo, Daniel Bensen, and Tiina Aumala
,=Anguillacertidae=Anguillacerta sinensis (Yangtze mosasaur)
=Mosasauridae=|
| ,=Archaeosaurocetacidae=Apep aegyptianus (Nile Mosasaur)
`=|
| ,=Gigantoserpentidae=Gigantoserpens microdon (Hobb's leviathan)
| |
| | ,=Pristrix monstrum Mosark
| | ,=|
| | | | ,=C. atrox (Zahn)
| | | `=Carcharosaurus=|
| | | | ,=C. crassus (Chubby mosark)
| | | `=|
| | | `=C. velox (Sakhala)
| | ,=|
| | | |=? Nodens incredibilis (Nodens)
| | | |
| | | | ,=N. gracilis (Longtailed lizardwhale)
| | | `=Naucratisaurus=|
| | | `=N. atlanticus (Azure lizardwhale)
| | ,=|
| | | | ,=S. pelagios (Prownose lizardwhale)
| | | | ,=Saurocetaceus=|
| | | | | `=S. brianchooi (Choo's lizardwhale)
| | | `=|
| | | `=Phocoenalacerta nigra (Mosapoise)
`=Saurocetaciodea=| |
`=Saurocetacidae=|
`=Pristisaurus peculiaris (Sawsnout lizardwhale)
Back
Mosasaurs (clade Mosasauridae) evolved during the late Mesozoic when a group of monitorlike lizards entered the ocean. These toothy, serpentine
predators might have seemed chunky and illmade when compared to the other marine predators of the time. However, while the ichthyosaurs went extinct
before the end of the Cretaceous and the plesiosaurs soon after, the mosasaurs have gone on to become one of the largest and most diverse clades of marine
vertebrates.
Most presentday mosasaurs are quite unlike their serpentine forebears. Whatever environmental catastrophe that mauled the archaeocetaceans in our world
almost had the same effect on the Late Eocene mosasaurs. Gone were the huge, 15m long tylosaurine seaserpents and their kin, never to return.
ANGUILLACERTIDAE (TiLung)
Years after specbiologists had concluded that none of the ancestral, longbodied mosasaurs
survived to the present day, the illustrious Tiina Aumala proved the existence of Anguillacerta
sinensis, the tilung.
(fig. 1) Yangtze mosasaur, Anguillacerta sinensis (Central and southern Asia)
Anguillacerta possesses nostrils placed above the eyes, as in the saurocetes, but its body is long, the tail is laterally flattened and possesses no fluke, and the
hind limbs are missing altogether. This cryptic piscivore is clearly a mosasaur, but is only distantly related to the saurocetes and is loosely allied with the
archaic forms that supposedly died out at the end of the Eocene.
ARCHAEOSAUROCETACIDAE (Apeps)
The earlyEocene radiation that produced the eellike river mosasaurs also resulted in the birth of the saurocetes, the most common of the extant mosasaur
groups. The first saurocetes, from the Eocene, are similar to modern forms, but fossil impressions show that they did not possess the paired tailfluke of the
advanced lizardwhales. Only a single species remains of this once mighty group.
The apep is a piscivorous aquatic lizard that today seems to be restricted to the
river Nile. Apeps can reach the length of 4.5 meters, though such venerable
individuals are rarely seen, and 23 meter long mosasaurs are more common.
(fig. 2) Apep, Apep aegypianus (Northern Africa)
Though at first the apep seems to resemble the serpentine longbodied yangtze mosasaur, it is acutally the last remaining archaeosaurocetid, or ansestral
saurocete, closely resembling fossil species such as Balaenanguis. Based on the patchy fossil record, genus Apep seems to date back at least to the
Oligocene (and possibly the Eocene) and has barely changed at all after it first appeared.
GIGANTOSERPENTIDAE (Leviathans)
The first evidence of one of Spec's most enigmatic seagiants washed up on a stony beach in eastern Africa after a particularly stormy night. The discoverer,
a certain Calvin Hobb, was apparently walking dangerously near the choppy shore when a sudden, violent surge practically dumped the specimen at his feet.
It was a cylindrical mass of rotting flesh over twelve metres in length. Within one end of the carcass, researchers recovered the twometre long skull minus the
lower jaw, the vertebral column up to the 17th dorsal and parts of right forepaddle. An examination of the bones made it clear that the carcass, now dubbed
"Hobb's Leviathan" represented a new species of mosasaur, but of what kind? Popular initial reports claimed that it represented a "living fossil", an archaic
longbodied mosasaurid that had escaped the Eocene extinction. More cautious researchers noted apparent similarities with the needlelike teeth and gracile
bodyform of the Yangtze mosasaur, suggesting a relationship with anguillacertids. Regardless of where it fitted amongst the Mosasauria, the skull and
vertebrae were sufficient cause to warrant it's description as a new species Gigantoserpens microdon, "the teenytoothed gigantic serpent"
(fig. 3) Early reconstruction of Hobb's Leviathan done prior to its description. Illustration by Tiina Aumala
Despite the incompleteness of the remains, the idea of a giant seaserpent was irresistable and a number of popular reconstructions depicted the
animal as an vast eellike creature with a stated length of over 25 metres. Soon sightings of giant killer serpents began cropping up everywhere
from the Caribbean to the bottom of Tiina's beer stein. Hoaxes pertaining to leviathanrelated fatalities at sea soon led to much hysteria. Nothing
more was heard from the real Gigantoserpens for over three years until a vessel surveying the west coast of South America produced blurry
photographs of a huge sea creature near San Ambrosio. They appeared to show nothing less than a supposedly extinct longnecked plesiosaur,
an animal that seemed to possess a small head, longneck and a bulbous, flippered body. An expedition to learn more of this creature was
hastily dispatched and it was soon ascertained that these "plesiosaurs" were in fact the real Hobb's leviathans.
The true appearance of these giant mosasaurs was completely
unexpected and nothing like the snakelike hypothetical
reconstructions. Instead of a vicious predator, the real leviathan
proved to be a sluggish, passive hunter of small prey. Rather than a
relic of the Eocene or some giant oceangoing rivermosasaur,
Gigantoserpens turned out to be a highly aberrant truesaurocetean
although different enough to be placed, along with subsequently
discovered Pliocene fossil forms, into a new clade the
Gigantoserpentidae.
(fig. 4)A living Gigantoserpens photographed off the west coast of South America. At "only" 11 metres in length, this is a relatively small individual.
HOBB'S LEVIATHAN DESCRIBED
(fig. 5)Skeletal silhouette of Hobb's leviathan alongside the incomplete holotype specimen and a human diver (diver courtesy Tiina Aumala)
Gigantoserpens is a bizarre saurocetacean that can reach a length of 21 metres and weigh in at an estimated 60 tonnes making it by far the
largest known squamate. The head is comparatively small and flat, sitting on a very short neck behind which sprout a pair of small flippers.
These are often held against the neck and can be difficult to discern from a distance.
The anterior dorsal vertebrae are lightweight while the associated ribs are greatly reduced in size. Thus in life, the forequarters of the animal
appear slender and snakelike, creating the illusion of an elongated neck. Further down the trunk the vertebrae become drastically larger and
more robust while the length and girth of the ribs increases causing the body to balloon out. The pelvic girdle and hindflippers are incredibly
large by mosasaur standards whilst the tail is exceptionally long and deep with prominant lateral keels, terminating in a huge caudalfin. A low,
triangular dorsal fin is located midway along the tail.
The dentition consists of numerous fine needlelike teeth and the lower jaw is loosely attached to the skull
allowing for a very wide gape. The interior of the mouth contains a series of rugosities called gnathochromes
which are infested with growths of luminescent bacteria that are clearly visible when the jaws are opened.
(fig. 6) (left) Frontal view of open mouth showing gnathochromes rugosities on which grow clusters of luminescent bacteria. The pterygoid teeth have been reduced to a
small row of nodules that are not externally visible on large adults. (right) Appearance of glowing gnathochromes in dark water. The precise arrangement varies between
individuals.
(fig. 7)Near the Azores, a Hobb's leviathan disappears in a great cloud of poo.
One unusual internal feature is a large sac on the lower intestine that can be filled with over 90 litres of reddishbrown syrupy faecal matter. When threatened
by a large carnivore, this liquid is expelled in a great, dense cloud that confuses or repels the attacker and gives the slowmoving leviathan the chance of
escape. A similar strategy is used (on a much smaller scale) by the HomeEarth pygmy sperm whales of the family Kogiidae.
The leviathan is primarily a mesopelagic predator that has been characterised as a "mosasaur trying to be an elasmosaur". Based on the stomach contents of
stranded individuals, it mostly feeds on nonshelly pelagic prey of up to a metre in length. It is not a choosy feeder and takes whatever happens to be
abundant in the area. While it has yet to be witnessed, it's feeding strategy probably involves cruising through the inky blackness with it's jaws agape. The
twinkling bacterial colonies in it's mouth give the impression of a swarm of bioluminescent plankton attracting shoals of fish, shrimp and squid to within easy
striking distance. The slender forequarters can curl and dart around with great speed, allowing it to snap up fasterswimming prey. The presence of injested
echinoderms and small skates suggest it also forages on the benthos, perhaps while gathering stones for ballast. One particularly scarred individual that was
recently stranded on New Caledonia was found to have a belly full of piranhakeets. The giant hindflippers are used for stability and steering, effectively filling
the role of pectoral fins on a more conventional sea creature. The stubby forepaddles seem to act as canard foreplanes, conferring a degree of hydrodynamic
stability to the anterior of the animal when on the move. While feeding, they are probably held conformally to avoid drag as the neck sweeps around.
Alternatively the forelimbs might play a role in sheperding prey although they seem a little too far from the mouth for this. Strandings and sightings indicate a
cosmopolitan species of deep offshore tropical to warm temperate seas. Although sparsely distributed, they are sometimes found in large feeding
concentrations and appear to have a habitat requirement for deep slope waters with steep depth gradients. Except for infrequent forays to the surface for air,
they follow the vertical migration of their prey, cruising at depths of over 900m during the day before rising to within 100m of the surface at night. Much
remains to be discovered about these remarkable giants and as yet we know nothing of their seasonal migrations, reproduction and development.
SAUROCETACIDAE (Mosarks and lizardwhales)
(fig. 8) A sampling of saurocetacidae (with apep)
1. Prownose lizardwhale
2. Apep
3. Zahn
4. Mosapoise
5. Mosark
6. Sawsnout lizardwhale
7. Longtailed lizardwhale
8. Sakhala
Currently the most highly specialized of marine reptiles, saurocetes do not bear much resemblance to their seaserpent ancestors, and rather resemble the
dolphins and whales of RL. Like the Jurassic ichthyosaurs before them and the odontocetaceans of our Earth, the ancestors of these creatures were long
bodied serpentine inshore predators (see above) that developed an increasingly fishlike body for a pelagic existence.
Saurocetes are fishlike marine squamates ranging from 1.5 to 15 metres in length. They are broadly analogous with our world's odontocetes but have not
produced a biggame carnivore in the same league as the orca. The scales have been completely lost and have been replaced with a smooth, leathery hide.
The paired nostrils are positioned at the top of the head. Propulsion is by strokes of a fishlike tail bearing 2 vertical flukes. All saurocetes are viviparous.
The precursors of the saurocetaceans were the huge predatory mosasaurs, marine squamates that evolved in the Cretaceous and were amongst the top
ocean predators from the Santonian to the Eocene. The decline of inland seas in the Maastrichtian put pressure on the mosasaurs to more fully exploit the
open oceans. One lineage abandoned the serpentine mosasaurbody, becoming more fishlike with a large falcate caudal fin replacing the simple spatulate
form.
While the Late Eocene disaster decimated their longbodied kin, the early saurocetaceans flourished, developing ever larger and larger forms. Today over 40
species ply the tropical to warm temperate oceans of the world, feeding mainly on cephalopods and small fish. However, they have been unable to venture
into the cooler sea. Those rich, polar killing grounds are the domains of warmblooded predators: birds like seaguins and penguins, and mammals like
walduks.
While HomeEarth's cetaceans cover a wide range of body types (from dolphins to whales), sarurocetes do not display so wide a diversity. There are no
filterfeeding mosasaurs, and the disparity between large and small species is relatively minimal. However, clear distinctions within Saurocetacidae do exist.
The carcharosaurines, or mosarks, are powerfullybuilt predators. Some, like the zahn, are truly enormous.
The mosark, cousin of the sakhala and zahn, is a 810 m long
predator of temperate oceans around the world. A mediumsized
pelagic predator, the mosark gained its name mainly from its shark
like appearance and behaviour, and many of its relatives are also often
unofficially referred to as mosarks for the same reason.
(fig. 9) Mosark, Pristrix monstrum (worldwide)
This lizardwhale is in many respects similiar to the zahn, though smaller and swifter. Though their diet mostly consists of cephalopods and fish, mosarks are
also known to attack small lizardwhales and other marine vertebrates.
The zahn is one of the largest lizardwhales. This 14 m
long solitary predator is large enough to swallow small
wingsquid whole and tear fully grown mantasquid into
pieces. Zhans attack just about anything big enough to
fit between their enormous jaws, including seabirds,
rays, sharks, swimming or wading dinosaurs, other
lizardwhales and inflatable boats filled with marine
biologists. There have been at least two unfortunate
incidents where Spec scientists have nearly ended up
in a zahn's bellythey were apparently saved only by
the foul taste of the boat. After that, small rubber
boats haven't been used in zahninfested waters.
(fig. 10) Zahn, Carcharosaurus atrox (Equatorial)
(fig. 11) Chubby mosark, Carcharosaurus crassus (Western Atlantic)
Warmed by the Gulf Stream, the waters off the coast of eastern North America are home to many predators, from walduks to sharks, but the most feared of
all is the chubby mosark. These odd little mosasaurs dart around the shallows from Florida to Newfoundland, snatching up anything that moves.
Despite its common name, the chubby mosark is only distantly related to the true mosarks (genus Pristrix). These creatures, are, in fact, close kin to the
zahns, massive, orcalike predators that hunt upper levels of the deep ocean. The chubby mosark, on the other hand, is one of several Carcharosaurus
lineages that have adapted for a life hunting the nutrientrich shallows of the continental shelves. These hunters are small, and rely upon their sensitive
Jacobson's organs to taste the water and home in on prey, rather than the easily confused eye. As a result, the eyes of the chubby mosark are rather small
and not very sensitive, while their chemical sense is superb.
Another way in which the chubby mosarks distinguish themselves is in their geographical range, which extends further north than any other marine mosasaur.
Although they winter in the warm waters off the coast of Florida, chubby mosasaurs spend the summer months rearing their pups in the Gulf of St. Lawrence.
This behavior is quite useful, since the habitat is devoid of competing mosasaurs, and the native pods of selkies make a tasty snack for the larger reptiles.
However, the northern water, although made bearable by the Gulf Stream, are still frigid to the coldblooded mosasaurs, and so chubby mosarks must
produce internal "coats" of insulating blubber, the source of their name.
(fig. 12) Sakhala, Carcharosaurus velox (Great Barrier Reef)
The Sakhala is a small (3 m long) and swift sharklike mosasaur that lives in the Great Barrier Reef. Though it mainly eats small fish and cephalopods, it may
attack anything smaller than a meter across if it looks edible.
(fig. 13) Nodens, Nodens incredibilis (Great Barrier Reef)
Ironically the largest known saurocete was not first discovered in the sea, but on dry land. During the first years of spexploration, some of the spexplorers
studying seaside ecosystems came across a gargantuan rotting hulk that had been washed ashore. It 18 meters long and was easily recognized as a
lizardwhale, but as the spexplorers lacked the appropriate equipment to transport that tonnage of meat, and the carcass was in such an advanced state of
decomposition that a further analysis was impossible to make at the time. The remains were hastily measured and photographed, and later some of the
skeletal remains were retrieved. These fragments became the holotype specimen of Nodens incredibilis.
Later, several other Nodens skeletons were discovered, and the largest of these, consisting of little more than a skull measuring over 4 meters long, lead to an
estimate of the adult size of Nodens, some 20 meters long, making it longest known marine vertebrate on Spec. It still took some time before the first verified
eyewitness sighting of a living specimen, but through a lucky coincidence, a group of marine biologists happened to be near a Nodens mating area, and
managed to film the animals both above and under water.
The film revealed that much of the forequarters of the giant lizardwhales were covered in curious looking scars, some resembling those left by giant squid
tentacles on sperm whales and others more unusual in appearance. It was deduced that the main diet of Nodens consisted of giant cephalopods, but the
peculiar scars lead to some dispute over what had caused them. Some claimed the lesions were bitemarks of some kind, while others blamed the infamous
great ktulu, which was reported as having feeding tentacles ending in handlike extensions covered in wicked hooks. A photograph of a large Nodens
individual with a severed end of a tentacle ending in just such fingerlike extensions still stuck on its skin only helped to fuel the controversy.
While the actual hunting and feeding of Nodens is yet to be observed, we do know that they are solitary most of the year and find their prey in the murky
depths of the ocean teeming with myriads of exotic cephalopod species. These saurocetes seem to fill the niche of HE sperm whales, although we can only
speculate at the differences in their hunting strategies. Despite having eyes not much larger than a human head, they are known to have a keen vision
especially in the dark. It is worth noting that Nodens are much more likely to move close to the surface at night than during the day.
While Nodens seemingly has a lot in common with mosarks, the latest analysis places it closest to nauticratisaurs. Though reports of Nodens individuals
longer than 20,5 meters are unverified, it still holds the record of the largest known mosasaur, being more massive (though not quite as long) as the leviathan.
Longtailed lizardwhales are a common species that form large schools off the western
coast of North America. They feed on a variety of small fish and cephalopods.
(fig. 13) Longtailed lizardwhale Naucratisaurus gracilis (Pacific)
A
close relative of the longtailed lizardwhale, the 45 meter long
azure lizardwhale forms large pods off the in the warm waters of the
Gulf Stream.
(fig. 14) Azure lizardwhale Naucratisaurus atlanticus (Atlantic)
The saurocetacines, on the other hand, are the more streamlined lizardwhales. Some possess long snouts and closely resemble the ichthyosaurs of Earth's
past and the dolphins of our home timeline.
One of the larger saurocetaceans, the prownose lizardwhale usually lives
alone but feeding aggregations of over 50 have been sighted. There are no
teeth in the upper jaw while 1214 conical teeth of each side of the dentary.
The prownose lizardwhale feeds primarily on cehalopods, including huge
barrelfish.
(fig. 15) Prownose lizardwhale Saurocetaceus pelagios (worldwide)
This cephalopodhunting saurocetacean lives in the Indian
ocean. Though closely related to the prownose lizardwhale,
Choo's lizardwhales rarely grow larger than 7 meters long.
These animals greatly resemble the Mesozoic ichtyosaurs,
which at first caused some confusion among the first
explorers of Spec.
(fig. 16) Choo's lizardwhale Saurocetaceus brianchooi (Indian Ocean)
(fig. 17) Mosapoise, Phocoenalacerta nigra (Equatorial Pacific)
The mosapoise is a 3.5 meters long saurocete specialized mostly on ammonoids, crabs, shellfishes and other hardshelled marine invertebrates it crushes with
its impressive battery of teeth.
The sawsnout lizardwhale, while clearly a saurocete, does not fit in with either the mosarks or the mosapoises. Some have allied this odd creature to apep,
the Nile mosasaur, but further studies are necessary to prove such a theory.
The sawsnout lizardwhale is undoubtedly one of the weirdest mosasaurs
in existence. Its upper jaw is disproportionally long and armed with
sharp outwardspointing teeth. Sawsnout lizardwhales use this weapon
to stun fastmoving prey and to rake out buried prey from the bottom.
(fig. 18) Sawsnout lizardwhale, Pristisaurus peculiaris(Caribbean)
Brian Choo, Daniel Bensen, and Tiina Aumala
,=Anguillacertidae=Anguillacerta sinensis (Yangtze mosasaur)
=Mosasauridae=|
| ,=Archaeosaurocetacidae=Apep aegyptianus (Nile Mosasaur)
`=|
| ,=Gigantoserpentidae=Gigantoserpens microdon (Hobb's leviathan)
| |
| | ,=Pristrix monstrum Mosark
| | ,=|
| | | | ,=C. atrox (Zahn)
| | | `=Carcharosaurus=|
| | | | ,=C. crassus (Chubby mosark)
| | | `=|
| | | `=C. velox (Sakhala)
| | ,=|
| | | |=? Nodens incredibilis (Nodens)
| | | |
| | | | ,=N. gracilis (Longtailed lizardwhale)
| | | `=Naucratisaurus=|
| | | `=N. atlanticus (Azure lizardwhale)
| | ,=|
| | | | ,=S. pelagios (Prownose lizardwhale)
| | | | ,=Saurocetaceus=|
| | | | | `=S. brianchooi (Choo's lizardwhale)
| | | `=|
| | | `=Phocoenalacerta nigra (Mosapoise)
`=Saurocetaciodea=| |
`=Saurocetacidae=|
`=Pristisaurus peculiaris (Sawsnout lizardwhale)
Back
Mosasaurs (clade Mosasauridae) evolved during the late Mesozoic when a group of monitorlike lizards entered the ocean. These toothy, serpentine
predators might have seemed chunky and illmade when compared to the other marine predators of the time. However, while the ichthyosaurs went extinct
before the end of the Cretaceous and the plesiosaurs soon after, the mosasaurs have gone on to become one of the largest and most diverse clades of marine
vertebrates.
Most presentday mosasaurs are quite unlike their serpentine forebears. Whatever environmental catastrophe that mauled the archaeocetaceans in our world
almost had the same effect on the Late Eocene mosasaurs. Gone were the huge, 15m long tylosaurine seaserpents and their kin, never to return.
ANGUILLACERTIDAE (TiLung)
Years after specbiologists had concluded that none of the ancestral, longbodied mosasaurs
survived to the present day, the illustrious Tiina Aumala proved the existence of Anguillacerta
sinensis, the tilung.
(fig. 1) Yangtze mosasaur, Anguillacerta sinensis (Central and southern Asia)
Anguillacerta possesses nostrils placed above the eyes, as in the saurocetes, but its body is long, the tail is laterally flattened and possesses no fluke, and the
hind limbs are missing altogether. This cryptic piscivore is clearly a mosasaur, but is only distantly related to the saurocetes and is loosely allied with the
archaic forms that supposedly died out at the end of the Eocene.
ARCHAEOSAUROCETACIDAE (Apeps)
The earlyEocene radiation that produced the eellike river mosasaurs also resulted in the birth of the saurocetes, the most common of the extant mosasaur
groups. The first saurocetes, from the Eocene, are similar to modern forms, but fossil impressions show that they did not possess the paired tailfluke of the
advanced lizardwhales. Only a single species remains of this once mighty group.
The apep is a piscivorous aquatic lizard that today seems to be restricted to the
river Nile. Apeps can reach the length of 4.5 meters, though such venerable
individuals are rarely seen, and 23 meter long mosasaurs are more common.
(fig. 2) Apep, Apep aegypianus (Northern Africa)
Though at first the apep seems to resemble the serpentine longbodied yangtze mosasaur, it is acutally the last remaining archaeosaurocetid, or ansestral
saurocete, closely resembling fossil species such as Balaenanguis. Based on the patchy fossil record, genus Apep seems to date back at least to the
Oligocene (and possibly the Eocene) and has barely changed at all after it first appeared.
GIGANTOSERPENTIDAE (Leviathans)
The first evidence of one of Spec's most enigmatic seagiants washed up on a stony beach in eastern Africa after a particularly stormy night. The discoverer,
a certain Calvin Hobb, was apparently walking dangerously near the choppy shore when a sudden, violent surge practically dumped the specimen at his feet.
It was a cylindrical mass of rotting flesh over twelve metres in length. Within one end of the carcass, researchers recovered the twometre long skull minus the
lower jaw, the vertebral column up to the 17th dorsal and parts of right forepaddle. An examination of the bones made it clear that the carcass, now dubbed
"Hobb's Leviathan" represented a new species of mosasaur, but of what kind? Popular initial reports claimed that it represented a "living fossil", an archaic
longbodied mosasaurid that had escaped the Eocene extinction. More cautious researchers noted apparent similarities with the needlelike teeth and gracile
bodyform of the Yangtze mosasaur, suggesting a relationship with anguillacertids. Regardless of where it fitted amongst the Mosasauria, the skull and
vertebrae were sufficient cause to warrant it's description as a new species Gigantoserpens microdon, "the teenytoothed gigantic serpent"
(fig. 3) Early reconstruction of Hobb's Leviathan done prior to its description. Illustration by Tiina Aumala
Despite the incompleteness of the remains, the idea of a giant seaserpent was irresistable and a number of popular reconstructions depicted the
animal as an vast eellike creature with a stated length of over 25 metres. Soon sightings of giant killer serpents began cropping up everywhere
from the Caribbean to the bottom of Tiina's beer stein. Hoaxes pertaining to leviathanrelated fatalities at sea soon led to much hysteria. Nothing
more was heard from the real Gigantoserpens for over three years until a vessel surveying the west coast of South America produced blurry
photographs of a huge sea creature near San Ambrosio. They appeared to show nothing less than a supposedly extinct longnecked plesiosaur,
an animal that seemed to possess a small head, longneck and a bulbous, flippered body. An expedition to learn more of this creature was
hastily dispatched and it was soon ascertained that these "plesiosaurs" were in fact the real Hobb's leviathans.
The true appearance of these giant mosasaurs was completely
unexpected and nothing like the snakelike hypothetical
reconstructions. Instead of a vicious predator, the real leviathan
proved to be a sluggish, passive hunter of small prey. Rather than a
relic of the Eocene or some giant oceangoing rivermosasaur,
Gigantoserpens turned out to be a highly aberrant truesaurocetean
although different enough to be placed, along with subsequently
discovered Pliocene fossil forms, into a new clade the
Gigantoserpentidae.
(fig. 4)A living Gigantoserpens photographed off the west coast of South America. At "only" 11 metres in length, this is a relatively small individual.
HOBB'S LEVIATHAN DESCRIBED
(fig. 5)Skeletal silhouette of Hobb's leviathan alongside the incomplete holotype specimen and a human diver (diver courtesy Tiina Aumala)
Gigantoserpens is a bizarre saurocetacean that can reach a length of 21 metres and weigh in at an estimated 60 tonnes making it by far the
largest known squamate. The head is comparatively small and flat, sitting on a very short neck behind which sprout a pair of small flippers.
These are often held against the neck and can be difficult to discern from a distance.
The anterior dorsal vertebrae are lightweight while the associated ribs are greatly reduced in size. Thus in life, the forequarters of the animal
appear slender and snakelike, creating the illusion of an elongated neck. Further down the trunk the vertebrae become drastically larger and
more robust while the length and girth of the ribs increases causing the body to balloon out. The pelvic girdle and hindflippers are incredibly
large by mosasaur standards whilst the tail is exceptionally long and deep with prominant lateral keels, terminating in a huge caudalfin. A low,
triangular dorsal fin is located midway along the tail.
The dentition consists of numerous fine needlelike teeth and the lower jaw is loosely attached to the skull
allowing for a very wide gape. The interior of the mouth contains a series of rugosities called gnathochromes
which are infested with growths of luminescent bacteria that are clearly visible when the jaws are opened.
(fig. 6) (left) Frontal view of open mouth showing gnathochromes rugosities on which grow clusters of luminescent bacteria. The pterygoid teeth have been reduced to a
small row of nodules that are not externally visible on large adults. (right) Appearance of glowing gnathochromes in dark water. The precise arrangement varies between
individuals.
(fig. 7)Near the Azores, a Hobb's leviathan disappears in a great cloud of poo.
One unusual internal feature is a large sac on the lower intestine that can be filled with over 90 litres of reddishbrown syrupy faecal matter. When threatened
by a large carnivore, this liquid is expelled in a great, dense cloud that confuses or repels the attacker and gives the slowmoving leviathan the chance of
escape. A similar strategy is used (on a much smaller scale) by the HomeEarth pygmy sperm whales of the family Kogiidae.
The leviathan is primarily a mesopelagic predator that has been characterised as a "mosasaur trying to be an elasmosaur". Based on the stomach contents of
stranded individuals, it mostly feeds on nonshelly pelagic prey of up to a metre in length. It is not a choosy feeder and takes whatever happens to be
abundant in the area. While it has yet to be witnessed, it's feeding strategy probably involves cruising through the inky blackness with it's jaws agape. The
twinkling bacterial colonies in it's mouth give the impression of a swarm of bioluminescent plankton attracting shoals of fish, shrimp and squid to within easy
striking distance. The slender forequarters can curl and dart around with great speed, allowing it to snap up fasterswimming prey. The presence of injested
echinoderms and small skates suggest it also forages on the benthos, perhaps while gathering stones for ballast. One particularly scarred individual that was
recently stranded on New Caledonia was found to have a belly full of piranhakeets. The giant hindflippers are used for stability and steering, effectively filling
the role of pectoral fins on a more conventional sea creature. The stubby forepaddles seem to act as canard foreplanes, conferring a degree of hydrodynamic
stability to the anterior of the animal when on the move. While feeding, they are probably held conformally to avoid drag as the neck sweeps around.
Alternatively the forelimbs might play a role in sheperding prey although they seem a little too far from the mouth for this. Strandings and sightings indicate a
cosmopolitan species of deep offshore tropical to warm temperate seas. Although sparsely distributed, they are sometimes found in large feeding
concentrations and appear to have a habitat requirement for deep slope waters with steep depth gradients. Except for infrequent forays to the surface for air,
they follow the vertical migration of their prey, cruising at depths of over 900m during the day before rising to within 100m of the surface at night. Much
remains to be discovered about these remarkable giants and as yet we know nothing of their seasonal migrations, reproduction and development.
SAUROCETACIDAE (Mosarks and lizardwhales)
(fig. 8) A sampling of saurocetacidae (with apep)
1. Prownose lizardwhale
2. Apep
3. Zahn
4. Mosapoise
5. Mosark
6. Sawsnout lizardwhale
7. Longtailed lizardwhale
8. Sakhala
Currently the most highly specialized of marine reptiles, saurocetes do not bear much resemblance to their seaserpent ancestors, and rather resemble the
dolphins and whales of RL. Like the Jurassic ichthyosaurs before them and the odontocetaceans of our Earth, the ancestors of these creatures were long
bodied serpentine inshore predators (see above) that developed an increasingly fishlike body for a pelagic existence.
Saurocetes are fishlike marine squamates ranging from 1.5 to 15 metres in length. They are broadly analogous with our world's odontocetes but have not
produced a biggame carnivore in the same league as the orca. The scales have been completely lost and have been replaced with a smooth, leathery hide.
The paired nostrils are positioned at the top of the head. Propulsion is by strokes of a fishlike tail bearing 2 vertical flukes. All saurocetes are viviparous.
The precursors of the saurocetaceans were the huge predatory mosasaurs, marine squamates that evolved in the Cretaceous and were amongst the top
ocean predators from the Santonian to the Eocene. The decline of inland seas in the Maastrichtian put pressure on the mosasaurs to more fully exploit the
open oceans. One lineage abandoned the serpentine mosasaurbody, becoming more fishlike with a large falcate caudal fin replacing the simple spatulate
form.
While the Late Eocene disaster decimated their longbodied kin, the early saurocetaceans flourished, developing ever larger and larger forms. Today over 40
species ply the tropical to warm temperate oceans of the world, feeding mainly on cephalopods and small fish. However, they have been unable to venture
into the cooler sea. Those rich, polar killing grounds are the domains of warmblooded predators: birds like seaguins and penguins, and mammals like
walduks.
While HomeEarth's cetaceans cover a wide range of body types (from dolphins to whales), sarurocetes do not display so wide a diversity. There are no
filterfeeding mosasaurs, and the disparity between large and small species is relatively minimal. However, clear distinctions within Saurocetacidae do exist.
The carcharosaurines, or mosarks, are powerfullybuilt predators. Some, like the zahn, are truly enormous.
The mosark, cousin of the sakhala and zahn, is a 810 m long
predator of temperate oceans around the world. A mediumsized
pelagic predator, the mosark gained its name mainly from its shark
like appearance and behaviour, and many of its relatives are also often
unofficially referred to as mosarks for the same reason.
(fig. 9) Mosark, Pristrix monstrum (worldwide)
This lizardwhale is in many respects similiar to the zahn, though smaller and swifter. Though their diet mostly consists of cephalopods and fish, mosarks are
also known to attack small lizardwhales and other marine vertebrates.
The zahn is one of the largest lizardwhales. This 14 m
long solitary predator is large enough to swallow small
wingsquid whole and tear fully grown mantasquid into
pieces. Zhans attack just about anything big enough to
fit between their enormous jaws, including seabirds,
rays, sharks, swimming or wading dinosaurs, other
lizardwhales and inflatable boats filled with marine
biologists. There have been at least two unfortunate
incidents where Spec scientists have nearly ended up
in a zahn's bellythey were apparently saved only by
the foul taste of the boat. After that, small rubber
boats haven't been used in zahninfested waters.
(fig. 10) Zahn, Carcharosaurus atrox (Equatorial)
(fig. 11) Chubby mosark, Carcharosaurus crassus (Western Atlantic)
Warmed by the Gulf Stream, the waters off the coast of eastern North America are home to many predators, from walduks to sharks, but the most feared of
all is the chubby mosark. These odd little mosasaurs dart around the shallows from Florida to Newfoundland, snatching up anything that moves.
Despite its common name, the chubby mosark is only distantly related to the true mosarks (genus Pristrix). These creatures, are, in fact, close kin to the
zahns, massive, orcalike predators that hunt upper levels of the deep ocean. The chubby mosark, on the other hand, is one of several Carcharosaurus
lineages that have adapted for a life hunting the nutrientrich shallows of the continental shelves. These hunters are small, and rely upon their sensitive
Jacobson's organs to taste the water and home in on prey, rather than the easily confused eye. As a result, the eyes of the chubby mosark are rather small
and not very sensitive, while their chemical sense is superb.
Another way in which the chubby mosarks distinguish themselves is in their geographical range, which extends further north than any other marine mosasaur.
Although they winter in the warm waters off the coast of Florida, chubby mosasaurs spend the summer months rearing their pups in the Gulf of St. Lawrence.
This behavior is quite useful, since the habitat is devoid of competing mosasaurs, and the native pods of selkies make a tasty snack for the larger reptiles.
However, the northern water, although made bearable by the Gulf Stream, are still frigid to the coldblooded mosasaurs, and so chubby mosarks must
produce internal "coats" of insulating blubber, the source of their name.
(fig. 12) Sakhala, Carcharosaurus velox (Great Barrier Reef)
The Sakhala is a small (3 m long) and swift sharklike mosasaur that lives in the Great Barrier Reef. Though it mainly eats small fish and cephalopods, it may
attack anything smaller than a meter across if it looks edible.
(fig. 13) Nodens, Nodens incredibilis (Great Barrier Reef)
Ironically the largest known saurocete was not first discovered in the sea, but on dry land. During the first years of spexploration, some of the spexplorers
studying seaside ecosystems came across a gargantuan rotting hulk that had been washed ashore. It 18 meters long and was easily recognized as a
lizardwhale, but as the spexplorers lacked the appropriate equipment to transport that tonnage of meat, and the carcass was in such an advanced state of
decomposition that a further analysis was impossible to make at the time. The remains were hastily measured and photographed, and later some of the
skeletal remains were retrieved. These fragments became the holotype specimen of Nodens incredibilis.
Later, several other Nodens skeletons were discovered, and the largest of these, consisting of little more than a skull measuring over 4 meters long, lead to an
estimate of the adult size of Nodens, some 20 meters long, making it longest known marine vertebrate on Spec. It still took some time before the first verified
eyewitness sighting of a living specimen, but through a lucky coincidence, a group of marine biologists happened to be near a Nodens mating area, and
managed to film the animals both above and under water.
The film revealed that much of the forequarters of the giant lizardwhales were covered in curious looking scars, some resembling those left by giant squid
tentacles on sperm whales and others more unusual in appearance. It was deduced that the main diet of Nodens consisted of giant cephalopods, but the
peculiar scars lead to some dispute over what had caused them. Some claimed the lesions were bitemarks of some kind, while others blamed the infamous
great ktulu, which was reported as having feeding tentacles ending in handlike extensions covered in wicked hooks. A photograph of a large Nodens
individual with a severed end of a tentacle ending in just such fingerlike extensions still stuck on its skin only helped to fuel the controversy.
While the actual hunting and feeding of Nodens is yet to be observed, we do know that they are solitary most of the year and find their prey in the murky
depths of the ocean teeming with myriads of exotic cephalopod species. These saurocetes seem to fill the niche of HE sperm whales, although we can only
speculate at the differences in their hunting strategies. Despite having eyes not much larger than a human head, they are known to have a keen vision
especially in the dark. It is worth noting that Nodens are much more likely to move close to the surface at night than during the day.
While Nodens seemingly has a lot in common with mosarks, the latest analysis places it closest to nauticratisaurs. Though reports of Nodens individuals
longer than 20,5 meters are unverified, it still holds the record of the largest known mosasaur, being more massive (though not quite as long) as the leviathan.
Longtailed lizardwhales are a common species that form large schools off the western
coast of North America. They feed on a variety of small fish and cephalopods.
(fig. 13) Longtailed lizardwhale Naucratisaurus gracilis (Pacific)
A
close relative of the longtailed lizardwhale, the 45 meter long
azure lizardwhale forms large pods off the in the warm waters of the
Gulf Stream.
(fig. 14) Azure lizardwhale Naucratisaurus atlanticus (Atlantic)
The saurocetacines, on the other hand, are the more streamlined lizardwhales. Some possess long snouts and closely resemble the ichthyosaurs of Earth's
past and the dolphins of our home timeline.
One of the larger saurocetaceans, the prownose lizardwhale usually lives
alone but feeding aggregations of over 50 have been sighted. There are no
teeth in the upper jaw while 1214 conical teeth of each side of the dentary.
The prownose lizardwhale feeds primarily on cehalopods, including huge
barrelfish.
(fig. 15) Prownose lizardwhale Saurocetaceus pelagios (worldwide)
This cephalopodhunting saurocetacean lives in the Indian
ocean. Though closely related to the prownose lizardwhale,
Choo's lizardwhales rarely grow larger than 7 meters long.
These animals greatly resemble the Mesozoic ichtyosaurs,
which at first caused some confusion among the first
explorers of Spec.
(fig. 16) Choo's lizardwhale Saurocetaceus brianchooi (Indian Ocean)
(fig. 17) Mosapoise, Phocoenalacerta nigra (Equatorial Pacific)
The mosapoise is a 3.5 meters long saurocete specialized mostly on ammonoids, crabs, shellfishes and other hardshelled marine invertebrates it crushes with
its impressive battery of teeth.
The sawsnout lizardwhale, while clearly a saurocete, does not fit in with either the mosarks or the mosapoises. Some have allied this odd creature to apep,
the Nile mosasaur, but further studies are necessary to prove such a theory.
The sawsnout lizardwhale is undoubtedly one of the weirdest mosasaurs
in existence. Its upper jaw is disproportionally long and armed with
sharp outwardspointing teeth. Sawsnout lizardwhales use this weapon
to stun fastmoving prey and to rake out buried prey from the bottom.
(fig. 18) Sawsnout lizardwhale, Pristisaurus peculiaris(Caribbean)
Brian Choo, Daniel Bensen, and Tiina Aumala
,=Anguillacertidae=Anguillacerta sinensis (Yangtze mosasaur)
=Mosasauridae=|
| ,=Archaeosaurocetacidae=Apep aegyptianus (Nile Mosasaur)
`=|
| ,=Gigantoserpentidae=Gigantoserpens microdon (Hobb's leviathan)
| |
| | ,=Pristrix monstrum Mosark
| | ,=|
| | | | ,=C. atrox (Zahn)
| | | `=Carcharosaurus=|
| | | | ,=C. crassus (Chubby mosark)
| | | `=|
| | | `=C. velox (Sakhala)
| | ,=|
| | | |=? Nodens incredibilis (Nodens)
| | | |
| | | | ,=N. gracilis (Longtailed lizardwhale)
| | | `=Naucratisaurus=|
| | | `=N. atlanticus (Azure lizardwhale)
| | ,=|
| | | | ,=S. pelagios (Prownose lizardwhale)
| | | | ,=Saurocetaceus=|
| | | | | `=S. brianchooi (Choo's lizardwhale)
| | | `=|
| | | `=Phocoenalacerta nigra (Mosapoise)
`=Saurocetaciodea=| |
`=Saurocetacidae=|
`=Pristisaurus peculiaris (Sawsnout lizardwhale)
Back
Mosasaurs (clade Mosasauridae) evolved during the late Mesozoic when a group of monitorlike lizards entered the ocean. These toothy, serpentine
predators might have seemed chunky and illmade when compared to the other marine predators of the time. However, while the ichthyosaurs went extinct
before the end of the Cretaceous and the plesiosaurs soon after, the mosasaurs have gone on to become one of the largest and most diverse clades of marine
vertebrates.
Most presentday mosasaurs are quite unlike their serpentine forebears. Whatever environmental catastrophe that mauled the archaeocetaceans in our world
almost had the same effect on the Late Eocene mosasaurs. Gone were the huge, 15m long tylosaurine seaserpents and their kin, never to return.
ANGUILLACERTIDAE (TiLung)
Years after specbiologists had concluded that none of the ancestral, longbodied mosasaurs
survived to the present day, the illustrious Tiina Aumala proved the existence of Anguillacerta
sinensis, the tilung.
(fig. 1) Yangtze mosasaur, Anguillacerta sinensis (Central and southern Asia)
Anguillacerta possesses nostrils placed above the eyes, as in the saurocetes, but its body is long, the tail is laterally flattened and possesses no fluke, and the
hind limbs are missing altogether. This cryptic piscivore is clearly a mosasaur, but is only distantly related to the saurocetes and is loosely allied with the
archaic forms that supposedly died out at the end of the Eocene.
ARCHAEOSAUROCETACIDAE (Apeps)
The earlyEocene radiation that produced the eellike river mosasaurs also resulted in the birth of the saurocetes, the most common of the extant mosasaur
groups. The first saurocetes, from the Eocene, are similar to modern forms, but fossil impressions show that they did not possess the paired tailfluke of the
advanced lizardwhales. Only a single species remains of this once mighty group.
The apep is a piscivorous aquatic lizard that today seems to be restricted to the
river Nile. Apeps can reach the length of 4.5 meters, though such venerable
individuals are rarely seen, and 23 meter long mosasaurs are more common.
(fig. 2) Apep, Apep aegypianus (Northern Africa)
Though at first the apep seems to resemble the serpentine longbodied yangtze mosasaur, it is acutally the last remaining archaeosaurocetid, or ansestral
saurocete, closely resembling fossil species such as Balaenanguis. Based on the patchy fossil record, genus Apep seems to date back at least to the
Oligocene (and possibly the Eocene) and has barely changed at all after it first appeared.
GIGANTOSERPENTIDAE (Leviathans)
The first evidence of one of Spec's most enigmatic seagiants washed up on a stony beach in eastern Africa after a particularly stormy night. The discoverer,
a certain Calvin Hobb, was apparently walking dangerously near the choppy shore when a sudden, violent surge practically dumped the specimen at his feet.
It was a cylindrical mass of rotting flesh over twelve metres in length. Within one end of the carcass, researchers recovered the twometre long skull minus the
lower jaw, the vertebral column up to the 17th dorsal and parts of right forepaddle. An examination of the bones made it clear that the carcass, now dubbed
"Hobb's Leviathan" represented a new species of mosasaur, but of what kind? Popular initial reports claimed that it represented a "living fossil", an archaic
longbodied mosasaurid that had escaped the Eocene extinction. More cautious researchers noted apparent similarities with the needlelike teeth and gracile
bodyform of the Yangtze mosasaur, suggesting a relationship with anguillacertids. Regardless of where it fitted amongst the Mosasauria, the skull and
vertebrae were sufficient cause to warrant it's description as a new species Gigantoserpens microdon, "the teenytoothed gigantic serpent"
(fig. 3) Early reconstruction of Hobb's Leviathan done prior to its description. Illustration by Tiina Aumala
Despite the incompleteness of the remains, the idea of a giant seaserpent was irresistable and a number of popular reconstructions depicted the
animal as an vast eellike creature with a stated length of over 25 metres. Soon sightings of giant killer serpents began cropping up everywhere
from the Caribbean to the bottom of Tiina's beer stein. Hoaxes pertaining to leviathanrelated fatalities at sea soon led to much hysteria. Nothing
more was heard from the real Gigantoserpens for over three years until a vessel surveying the west coast of South America produced blurry
photographs of a huge sea creature near San Ambrosio. They appeared to show nothing less than a supposedly extinct longnecked plesiosaur,
an animal that seemed to possess a small head, longneck and a bulbous, flippered body. An expedition to learn more of this creature was
hastily dispatched and it was soon ascertained that these "plesiosaurs" were in fact the real Hobb's leviathans.
The true appearance of these giant mosasaurs was completely
unexpected and nothing like the snakelike hypothetical
reconstructions. Instead of a vicious predator, the real leviathan
proved to be a sluggish, passive hunter of small prey. Rather than a
relic of the Eocene or some giant oceangoing rivermosasaur,
Gigantoserpens turned out to be a highly aberrant truesaurocetean
although different enough to be placed, along with subsequently
discovered Pliocene fossil forms, into a new clade the
Gigantoserpentidae.
(fig. 4)A living Gigantoserpens photographed off the west coast of South America. At "only" 11 metres in length, this is a relatively small individual.
HOBB'S LEVIATHAN DESCRIBED
(fig. 5)Skeletal silhouette of Hobb's leviathan alongside the incomplete holotype specimen and a human diver (diver courtesy Tiina Aumala)
Gigantoserpens is a bizarre saurocetacean that can reach a length of 21 metres and weigh in at an estimated 60 tonnes making it by far the
largest known squamate. The head is comparatively small and flat, sitting on a very short neck behind which sprout a pair of small flippers.
These are often held against the neck and can be difficult to discern from a distance.
The anterior dorsal vertebrae are lightweight while the associated ribs are greatly reduced in size. Thus in life, the forequarters of the animal
appear slender and snakelike, creating the illusion of an elongated neck. Further down the trunk the vertebrae become drastically larger and
more robust while the length and girth of the ribs increases causing the body to balloon out. The pelvic girdle and hindflippers are incredibly
large by mosasaur standards whilst the tail is exceptionally long and deep with prominant lateral keels, terminating in a huge caudalfin. A low,
triangular dorsal fin is located midway along the tail.
The dentition consists of numerous fine needlelike teeth and the lower jaw is loosely attached to the skull
allowing for a very wide gape. The interior of the mouth contains a series of rugosities called gnathochromes
which are infested with growths of luminescent bacteria that are clearly visible when the jaws are opened.
(fig. 6) (left) Frontal view of open mouth showing gnathochromes rugosities on which grow clusters of luminescent bacteria. The pterygoid teeth have been reduced to a
small row of nodules that are not externally visible on large adults. (right) Appearance of glowing gnathochromes in dark water. The precise arrangement varies between
individuals.
(fig. 7)Near the Azores, a Hobb's leviathan disappears in a great cloud of poo.
One unusual internal feature is a large sac on the lower intestine that can be filled with over 90 litres of reddishbrown syrupy faecal matter. When threatened
by a large carnivore, this liquid is expelled in a great, dense cloud that confuses or repels the attacker and gives the slowmoving leviathan the chance of
escape. A similar strategy is used (on a much smaller scale) by the HomeEarth pygmy sperm whales of the family Kogiidae.
The leviathan is primarily a mesopelagic predator that has been characterised as a "mosasaur trying to be an elasmosaur". Based on the stomach contents of
stranded individuals, it mostly feeds on nonshelly pelagic prey of up to a metre in length. It is not a choosy feeder and takes whatever happens to be
abundant in the area. While it has yet to be witnessed, it's feeding strategy probably involves cruising through the inky blackness with it's jaws agape. The
twinkling bacterial colonies in it's mouth give the impression of a swarm of bioluminescent plankton attracting shoals of fish, shrimp and squid to within easy
striking distance. The slender forequarters can curl and dart around with great speed, allowing it to snap up fasterswimming prey. The presence of injested
echinoderms and small skates suggest it also forages on the benthos, perhaps while gathering stones for ballast. One particularly scarred individual that was
recently stranded on New Caledonia was found to have a belly full of piranhakeets. The giant hindflippers are used for stability and steering, effectively filling
the role of pectoral fins on a more conventional sea creature. The stubby forepaddles seem to act as canard foreplanes, conferring a degree of hydrodynamic
stability to the anterior of the animal when on the move. While feeding, they are probably held conformally to avoid drag as the neck sweeps around.
Alternatively the forelimbs might play a role in sheperding prey although they seem a little too far from the mouth for this. Strandings and sightings indicate a
cosmopolitan species of deep offshore tropical to warm temperate seas. Although sparsely distributed, they are sometimes found in large feeding
concentrations and appear to have a habitat requirement for deep slope waters with steep depth gradients. Except for infrequent forays to the surface for air,
they follow the vertical migration of their prey, cruising at depths of over 900m during the day before rising to within 100m of the surface at night. Much
remains to be discovered about these remarkable giants and as yet we know nothing of their seasonal migrations, reproduction and development.
SAUROCETACIDAE (Mosarks and lizardwhales)
(fig. 8) A sampling of saurocetacidae (with apep)
1. Prownose lizardwhale
2. Apep
3. Zahn
4. Mosapoise
5. Mosark
6. Sawsnout lizardwhale
7. Longtailed lizardwhale
8. Sakhala
Currently the most highly specialized of marine reptiles, saurocetes do not bear much resemblance to their seaserpent ancestors, and rather resemble the
dolphins and whales of RL. Like the Jurassic ichthyosaurs before them and the odontocetaceans of our Earth, the ancestors of these creatures were long
bodied serpentine inshore predators (see above) that developed an increasingly fishlike body for a pelagic existence.
Saurocetes are fishlike marine squamates ranging from 1.5 to 15 metres in length. They are broadly analogous with our world's odontocetes but have not
produced a biggame carnivore in the same league as the orca. The scales have been completely lost and have been replaced with a smooth, leathery hide.
The paired nostrils are positioned at the top of the head. Propulsion is by strokes of a fishlike tail bearing 2 vertical flukes. All saurocetes are viviparous.
The precursors of the saurocetaceans were the huge predatory mosasaurs, marine squamates that evolved in the Cretaceous and were amongst the top
ocean predators from the Santonian to the Eocene. The decline of inland seas in the Maastrichtian put pressure on the mosasaurs to more fully exploit the
open oceans. One lineage abandoned the serpentine mosasaurbody, becoming more fishlike with a large falcate caudal fin replacing the simple spatulate
form.
While the Late Eocene disaster decimated their longbodied kin, the early saurocetaceans flourished, developing ever larger and larger forms. Today over 40
species ply the tropical to warm temperate oceans of the world, feeding mainly on cephalopods and small fish. However, they have been unable to venture
into the cooler sea. Those rich, polar killing grounds are the domains of warmblooded predators: birds like seaguins and penguins, and mammals like
walduks.
While HomeEarth's cetaceans cover a wide range of body types (from dolphins to whales), sarurocetes do not display so wide a diversity. There are no
filterfeeding mosasaurs, and the disparity between large and small species is relatively minimal. However, clear distinctions within Saurocetacidae do exist.
The carcharosaurines, or mosarks, are powerfullybuilt predators. Some, like the zahn, are truly enormous.
The mosark, cousin of the sakhala and zahn, is a 810 m long
predator of temperate oceans around the world. A mediumsized
pelagic predator, the mosark gained its name mainly from its shark
like appearance and behaviour, and many of its relatives are also often
unofficially referred to as mosarks for the same reason.
(fig. 9) Mosark, Pristrix monstrum (worldwide)
This lizardwhale is in many respects similiar to the zahn, though smaller and swifter. Though their diet mostly consists of cephalopods and fish, mosarks are
also known to attack small lizardwhales and other marine vertebrates.
The zahn is one of the largest lizardwhales. This 14 m
long solitary predator is large enough to swallow small
wingsquid whole and tear fully grown mantasquid into
pieces. Zhans attack just about anything big enough to
fit between their enormous jaws, including seabirds,
rays, sharks, swimming or wading dinosaurs, other
lizardwhales and inflatable boats filled with marine
biologists. There have been at least two unfortunate
incidents where Spec scientists have nearly ended up
in a zahn's bellythey were apparently saved only by
the foul taste of the boat. After that, small rubber
boats haven't been used in zahninfested waters.
(fig. 10) Zahn, Carcharosaurus atrox (Equatorial)
(fig. 11) Chubby mosark, Carcharosaurus crassus (Western Atlantic)
Warmed by the Gulf Stream, the waters off the coast of eastern North America are home to many predators, from walduks to sharks, but the most feared of
all is the chubby mosark. These odd little mosasaurs dart around the shallows from Florida to Newfoundland, snatching up anything that moves.
Despite its common name, the chubby mosark is only distantly related to the true mosarks (genus Pristrix). These creatures, are, in fact, close kin to the
zahns, massive, orcalike predators that hunt upper levels of the deep ocean. The chubby mosark, on the other hand, is one of several Carcharosaurus
lineages that have adapted for a life hunting the nutrientrich shallows of the continental shelves. These hunters are small, and rely upon their sensitive
Jacobson's organs to taste the water and home in on prey, rather than the easily confused eye. As a result, the eyes of the chubby mosark are rather small
and not very sensitive, while their chemical sense is superb.
Another way in which the chubby mosarks distinguish themselves is in their geographical range, which extends further north than any other marine mosasaur.
Although they winter in the warm waters off the coast of Florida, chubby mosasaurs spend the summer months rearing their pups in the Gulf of St. Lawrence.
This behavior is quite useful, since the habitat is devoid of competing mosasaurs, and the native pods of selkies make a tasty snack for the larger reptiles.
However, the northern water, although made bearable by the Gulf Stream, are still frigid to the coldblooded mosasaurs, and so chubby mosarks must
produce internal "coats" of insulating blubber, the source of their name.
(fig. 12) Sakhala, Carcharosaurus velox (Great Barrier Reef)
The Sakhala is a small (3 m long) and swift sharklike mosasaur that lives in the Great Barrier Reef. Though it mainly eats small fish and cephalopods, it may
attack anything smaller than a meter across if it looks edible.
(fig. 13) Nodens, Nodens incredibilis (Great Barrier Reef)
Ironically the largest known saurocete was not first discovered in the sea, but on dry land. During the first years of spexploration, some of the spexplorers
studying seaside ecosystems came across a gargantuan rotting hulk that had been washed ashore. It 18 meters long and was easily recognized as a
lizardwhale, but as the spexplorers lacked the appropriate equipment to transport that tonnage of meat, and the carcass was in such an advanced state of
decomposition that a further analysis was impossible to make at the time. The remains were hastily measured and photographed, and later some of the
skeletal remains were retrieved. These fragments became the holotype specimen of Nodens incredibilis.
Later, several other Nodens skeletons were discovered, and the largest of these, consisting of little more than a skull measuring over 4 meters long, lead to an
estimate of the adult size of Nodens, some 20 meters long, making it longest known marine vertebrate on Spec. It still took some time before the first verified
eyewitness sighting of a living specimen, but through a lucky coincidence, a group of marine biologists happened to be near a Nodens mating area, and
managed to film the animals both above and under water.
The film revealed that much of the forequarters of the giant lizardwhales were covered in curious looking scars, some resembling those left by giant squid
tentacles on sperm whales and others more unusual in appearance. It was deduced that the main diet of Nodens consisted of giant cephalopods, but the
peculiar scars lead to some dispute over what had caused them. Some claimed the lesions were bitemarks of some kind, while others blamed the infamous
great ktulu, which was reported as having feeding tentacles ending in handlike extensions covered in wicked hooks. A photograph of a large Nodens
individual with a severed end of a tentacle ending in just such fingerlike extensions still stuck on its skin only helped to fuel the controversy.
While the actual hunting and feeding of Nodens is yet to be observed, we do know that they are solitary most of the year and find their prey in the murky
depths of the ocean teeming with myriads of exotic cephalopod species. These saurocetes seem to fill the niche of HE sperm whales, although we can only
speculate at the differences in their hunting strategies. Despite having eyes not much larger than a human head, they are known to have a keen vision
especially in the dark. It is worth noting that Nodens are much more likely to move close to the surface at night than during the day.
While Nodens seemingly has a lot in common with mosarks, the latest analysis places it closest to nauticratisaurs. Though reports of Nodens individuals
longer than 20,5 meters are unverified, it still holds the record of the largest known mosasaur, being more massive (though not quite as long) as the leviathan.
Longtailed lizardwhales are a common species that form large schools off the western
coast of North America. They feed on a variety of small fish and cephalopods.
(fig. 13) Longtailed lizardwhale Naucratisaurus gracilis (Pacific)
A
close relative of the longtailed lizardwhale, the 45 meter long
azure lizardwhale forms large pods off the in the warm waters of the
Gulf Stream.
(fig. 14) Azure lizardwhale Naucratisaurus atlanticus (Atlantic)
The saurocetacines, on the other hand, are the more streamlined lizardwhales. Some possess long snouts and closely resemble the ichthyosaurs of Earth's
past and the dolphins of our home timeline.
One of the larger saurocetaceans, the prownose lizardwhale usually lives
alone but feeding aggregations of over 50 have been sighted. There are no
teeth in the upper jaw while 1214 conical teeth of each side of the dentary.
The prownose lizardwhale feeds primarily on cehalopods, including huge
barrelfish.
(fig. 15) Prownose lizardwhale Saurocetaceus pelagios (worldwide)
This cephalopodhunting saurocetacean lives in the Indian
ocean. Though closely related to the prownose lizardwhale,
Choo's lizardwhales rarely grow larger than 7 meters long.
These animals greatly resemble the Mesozoic ichtyosaurs,
which at first caused some confusion among the first
explorers of Spec.
(fig. 16) Choo's lizardwhale Saurocetaceus brianchooi (Indian Ocean)
(fig. 17) Mosapoise, Phocoenalacerta nigra (Equatorial Pacific)
The mosapoise is a 3.5 meters long saurocete specialized mostly on ammonoids, crabs, shellfishes and other hardshelled marine invertebrates it crushes with
its impressive battery of teeth.
The sawsnout lizardwhale, while clearly a saurocete, does not fit in with either the mosarks or the mosapoises. Some have allied this odd creature to apep,
the Nile mosasaur, but further studies are necessary to prove such a theory.
The sawsnout lizardwhale is undoubtedly one of the weirdest mosasaurs
in existence. Its upper jaw is disproportionally long and armed with
sharp outwardspointing teeth. Sawsnout lizardwhales use this weapon
to stun fastmoving prey and to rake out buried prey from the bottom.
(fig. 18) Sawsnout lizardwhale, Pristisaurus peculiaris(Caribbean)
Brian Choo, Daniel Bensen, and Tiina Aumala
,=Anguillacertidae=Anguillacerta sinensis (Yangtze mosasaur)
=Mosasauridae=|
| ,=Archaeosaurocetacidae=Apep aegyptianus (Nile Mosasaur)
`=|
| ,=Gigantoserpentidae=Gigantoserpens microdon (Hobb's leviathan)
| |
| | ,=Pristrix monstrum Mosark
| | ,=|
| | | | ,=C. atrox (Zahn)
| | | `=Carcharosaurus=|
| | | | ,=C. crassus (Chubby mosark)
| | | `=|
| | | `=C. velox (Sakhala)
| | ,=|
| | | |=? Nodens incredibilis (Nodens)
| | | |
| | | | ,=N. gracilis (Longtailed lizardwhale)
| | | `=Naucratisaurus=|
| | | `=N. atlanticus (Azure lizardwhale)
| | ,=|
| | | | ,=S. pelagios (Prownose lizardwhale)
| | | | ,=Saurocetaceus=|
| | | | | `=S. brianchooi (Choo's lizardwhale)
| | | `=|
| | | `=Phocoenalacerta nigra (Mosapoise)
`=Saurocetaciodea=| |
`=Saurocetacidae=|
`=Pristisaurus peculiaris (Sawsnout lizardwhale)
Back
Mosasaurs (clade Mosasauridae) evolved during the late Mesozoic when a group of monitorlike lizards entered the ocean. These toothy, serpentine
predators might have seemed chunky and illmade when compared to the other marine predators of the time. However, while the ichthyosaurs went extinct
before the end of the Cretaceous and the plesiosaurs soon after, the mosasaurs have gone on to become one of the largest and most diverse clades of marine
vertebrates.
Most presentday mosasaurs are quite unlike their serpentine forebears. Whatever environmental catastrophe that mauled the archaeocetaceans in our world
almost had the same effect on the Late Eocene mosasaurs. Gone were the huge, 15m long tylosaurine seaserpents and their kin, never to return.
ANGUILLACERTIDAE (TiLung)
Years after specbiologists had concluded that none of the ancestral, longbodied mosasaurs
survived to the present day, the illustrious Tiina Aumala proved the existence of Anguillacerta
sinensis, the tilung.
(fig. 1) Yangtze mosasaur, Anguillacerta sinensis (Central and southern Asia)
Anguillacerta possesses nostrils placed above the eyes, as in the saurocetes, but its body is long, the tail is laterally flattened and possesses no fluke, and the
hind limbs are missing altogether. This cryptic piscivore is clearly a mosasaur, but is only distantly related to the saurocetes and is loosely allied with the
archaic forms that supposedly died out at the end of the Eocene.
ARCHAEOSAUROCETACIDAE (Apeps)
The earlyEocene radiation that produced the eellike river mosasaurs also resulted in the birth of the saurocetes, the most common of the extant mosasaur
groups. The first saurocetes, from the Eocene, are similar to modern forms, but fossil impressions show that they did not possess the paired tailfluke of the
advanced lizardwhales. Only a single species remains of this once mighty group.
The apep is a piscivorous aquatic lizard that today seems to be restricted to the
river Nile. Apeps can reach the length of 4.5 meters, though such venerable
individuals are rarely seen, and 23 meter long mosasaurs are more common.
(fig. 2) Apep, Apep aegypianus (Northern Africa)
Though at first the apep seems to resemble the serpentine longbodied yangtze mosasaur, it is acutally the last remaining archaeosaurocetid, or ansestral
saurocete, closely resembling fossil species such as Balaenanguis. Based on the patchy fossil record, genus Apep seems to date back at least to the
Oligocene (and possibly the Eocene) and has barely changed at all after it first appeared.
GIGANTOSERPENTIDAE (Leviathans)
The first evidence of one of Spec's most enigmatic seagiants washed up on a stony beach in eastern Africa after a particularly stormy night. The discoverer,
a certain Calvin Hobb, was apparently walking dangerously near the choppy shore when a sudden, violent surge practically dumped the specimen at his feet.
It was a cylindrical mass of rotting flesh over twelve metres in length. Within one end of the carcass, researchers recovered the twometre long skull minus the
lower jaw, the vertebral column up to the 17th dorsal and parts of right forepaddle. An examination of the bones made it clear that the carcass, now dubbed
"Hobb's Leviathan" represented a new species of mosasaur, but of what kind? Popular initial reports claimed that it represented a "living fossil", an archaic
longbodied mosasaurid that had escaped the Eocene extinction. More cautious researchers noted apparent similarities with the needlelike teeth and gracile
bodyform of the Yangtze mosasaur, suggesting a relationship with anguillacertids. Regardless of where it fitted amongst the Mosasauria, the skull and
vertebrae were sufficient cause to warrant it's description as a new species Gigantoserpens microdon, "the teenytoothed gigantic serpent"
(fig. 3) Early reconstruction of Hobb's Leviathan done prior to its description. Illustration by Tiina Aumala
Despite the incompleteness of the remains, the idea of a giant seaserpent was irresistable and a number of popular reconstructions depicted the
animal as an vast eellike creature with a stated length of over 25 metres. Soon sightings of giant killer serpents began cropping up everywhere
from the Caribbean to the bottom of Tiina's beer stein. Hoaxes pertaining to leviathanrelated fatalities at sea soon led to much hysteria. Nothing
more was heard from the real Gigantoserpens for over three years until a vessel surveying the west coast of South America produced blurry
photographs of a huge sea creature near San Ambrosio. They appeared to show nothing less than a supposedly extinct longnecked plesiosaur,
an animal that seemed to possess a small head, longneck and a bulbous, flippered body. An expedition to learn more of this creature was
hastily dispatched and it was soon ascertained that these "plesiosaurs" were in fact the real Hobb's leviathans.
The true appearance of these giant mosasaurs was completely
unexpected and nothing like the snakelike hypothetical
reconstructions. Instead of a vicious predator, the real leviathan
proved to be a sluggish, passive hunter of small prey. Rather than a
relic of the Eocene or some giant oceangoing rivermosasaur,
Gigantoserpens turned out to be a highly aberrant truesaurocetean
although different enough to be placed, along with subsequently
discovered Pliocene fossil forms, into a new clade the
Gigantoserpentidae.
(fig. 4)A living Gigantoserpens photographed off the west coast of South America. At "only" 11 metres in length, this is a relatively small individual.
HOBB'S LEVIATHAN DESCRIBED
(fig. 5)Skeletal silhouette of Hobb's leviathan alongside the incomplete holotype specimen and a human diver (diver courtesy Tiina Aumala)
Gigantoserpens is a bizarre saurocetacean that can reach a length of 21 metres and weigh in at an estimated 60 tonnes making it by far the
largest known squamate. The head is comparatively small and flat, sitting on a very short neck behind which sprout a pair of small flippers.
These are often held against the neck and can be difficult to discern from a distance.
The anterior dorsal vertebrae are lightweight while the associated ribs are greatly reduced in size. Thus in life, the forequarters of the animal
appear slender and snakelike, creating the illusion of an elongated neck. Further down the trunk the vertebrae become drastically larger and
more robust while the length and girth of the ribs increases causing the body to balloon out. The pelvic girdle and hindflippers are incredibly
large by mosasaur standards whilst the tail is exceptionally long and deep with prominant lateral keels, terminating in a huge caudalfin. A low,
triangular dorsal fin is located midway along the tail.
The dentition consists of numerous fine needlelike teeth and the lower jaw is loosely attached to the skull
allowing for a very wide gape. The interior of the mouth contains a series of rugosities called gnathochromes
which are infested with growths of luminescent bacteria that are clearly visible when the jaws are opened.
(fig. 6) (left) Frontal view of open mouth showing gnathochromes rugosities on which grow clusters of luminescent bacteria. The pterygoid teeth have been reduced to a
small row of nodules that are not externally visible on large adults. (right) Appearance of glowing gnathochromes in dark water. The precise arrangement varies between
individuals.
(fig. 7)Near the Azores, a Hobb's leviathan disappears in a great cloud of poo.
One unusual internal feature is a large sac on the lower intestine that can be filled with over 90 litres of reddishbrown syrupy faecal matter. When threatened
by a large carnivore, this liquid is expelled in a great, dense cloud that confuses or repels the attacker and gives the slowmoving leviathan the chance of
escape. A similar strategy is used (on a much smaller scale) by the HomeEarth pygmy sperm whales of the family Kogiidae.
The leviathan is primarily a mesopelagic predator that has been characterised as a "mosasaur trying to be an elasmosaur". Based on the stomach contents of
stranded individuals, it mostly feeds on nonshelly pelagic prey of up to a metre in length. It is not a choosy feeder and takes whatever happens to be
abundant in the area. While it has yet to be witnessed, it's feeding strategy probably involves cruising through the inky blackness with it's jaws agape. The
twinkling bacterial colonies in it's mouth give the impression of a swarm of bioluminescent plankton attracting shoals of fish, shrimp and squid to within easy
striking distance. The slender forequarters can curl and dart around with great speed, allowing it to snap up fasterswimming prey. The presence of injested
echinoderms and small skates suggest it also forages on the benthos, perhaps while gathering stones for ballast. One particularly scarred individual that was
recently stranded on New Caledonia was found to have a belly full of piranhakeets. The giant hindflippers are used for stability and steering, effectively filling
the role of pectoral fins on a more conventional sea creature. The stubby forepaddles seem to act as canard foreplanes, conferring a degree of hydrodynamic
stability to the anterior of the animal when on the move. While feeding, they are probably held conformally to avoid drag as the neck sweeps around.
Alternatively the forelimbs might play a role in sheperding prey although they seem a little too far from the mouth for this. Strandings and sightings indicate a
cosmopolitan species of deep offshore tropical to warm temperate seas. Although sparsely distributed, they are sometimes found in large feeding
concentrations and appear to have a habitat requirement for deep slope waters with steep depth gradients. Except for infrequent forays to the surface for air,
they follow the vertical migration of their prey, cruising at depths of over 900m during the day before rising to within 100m of the surface at night. Much
remains to be discovered about these remarkable giants and as yet we know nothing of their seasonal migrations, reproduction and development.
SAUROCETACIDAE (Mosarks and lizardwhales)
(fig. 8) A sampling of saurocetacidae (with apep)
1. Prownose lizardwhale
2. Apep
3. Zahn
4. Mosapoise
5. Mosark
6. Sawsnout lizardwhale
7. Longtailed lizardwhale
8. Sakhala
Currently the most highly specialized of marine reptiles, saurocetes do not bear much resemblance to their seaserpent ancestors, and rather resemble the
dolphins and whales of RL. Like the Jurassic ichthyosaurs before them and the odontocetaceans of our Earth, the ancestors of these creatures were long
bodied serpentine inshore predators (see above) that developed an increasingly fishlike body for a pelagic existence.
Saurocetes are fishlike marine squamates ranging from 1.5 to 15 metres in length. They are broadly analogous with our world's odontocetes but have not
produced a biggame carnivore in the same league as the orca. The scales have been completely lost and have been replaced with a smooth, leathery hide.
The paired nostrils are positioned at the top of the head. Propulsion is by strokes of a fishlike tail bearing 2 vertical flukes. All saurocetes are viviparous.
The precursors of the saurocetaceans were the huge predatory mosasaurs, marine squamates that evolved in the Cretaceous and were amongst the top
ocean predators from the Santonian to the Eocene. The decline of inland seas in the Maastrichtian put pressure on the mosasaurs to more fully exploit the
open oceans. One lineage abandoned the serpentine mosasaurbody, becoming more fishlike with a large falcate caudal fin replacing the simple spatulate
form.
While the Late Eocene disaster decimated their longbodied kin, the early saurocetaceans flourished, developing ever larger and larger forms. Today over 40
species ply the tropical to warm temperate oceans of the world, feeding mainly on cephalopods and small fish. However, they have been unable to venture
into the cooler sea. Those rich, polar killing grounds are the domains of warmblooded predators: birds like seaguins and penguins, and mammals like
walduks.
While HomeEarth's cetaceans cover a wide range of body types (from dolphins to whales), sarurocetes do not display so wide a diversity. There are no
filterfeeding mosasaurs, and the disparity between large and small species is relatively minimal. However, clear distinctions within Saurocetacidae do exist.
The carcharosaurines, or mosarks, are powerfullybuilt predators. Some, like the zahn, are truly enormous.
The mosark, cousin of the sakhala and zahn, is a 810 m long
predator of temperate oceans around the world. A mediumsized
pelagic predator, the mosark gained its name mainly from its shark
like appearance and behaviour, and many of its relatives are also often
unofficially referred to as mosarks for the same reason.
(fig. 9) Mosark, Pristrix monstrum (worldwide)
This lizardwhale is in many respects similiar to the zahn, though smaller and swifter. Though their diet mostly consists of cephalopods and fish, mosarks are
also known to attack small lizardwhales and other marine vertebrates.
The zahn is one of the largest lizardwhales. This 14 m
long solitary predator is large enough to swallow small
wingsquid whole and tear fully grown mantasquid into
pieces. Zhans attack just about anything big enough to
fit between their enormous jaws, including seabirds,
rays, sharks, swimming or wading dinosaurs, other
lizardwhales and inflatable boats filled with marine
biologists. There have been at least two unfortunate
incidents where Spec scientists have nearly ended up
in a zahn's bellythey were apparently saved only by
the foul taste of the boat. After that, small rubber
boats haven't been used in zahninfested waters.
(fig. 10) Zahn, Carcharosaurus atrox (Equatorial)
(fig. 11) Chubby mosark, Carcharosaurus crassus (Western Atlantic)
Warmed by the Gulf Stream, the waters off the coast of eastern North America are home to many predators, from walduks to sharks, but the most feared of
all is the chubby mosark. These odd little mosasaurs dart around the shallows from Florida to Newfoundland, snatching up anything that moves.
Despite its common name, the chubby mosark is only distantly related to the true mosarks (genus Pristrix). These creatures, are, in fact, close kin to the
zahns, massive, orcalike predators that hunt upper levels of the deep ocean. The chubby mosark, on the other hand, is one of several Carcharosaurus
lineages that have adapted for a life hunting the nutrientrich shallows of the continental shelves. These hunters are small, and rely upon their sensitive
Jacobson's organs to taste the water and home in on prey, rather than the easily confused eye. As a result, the eyes of the chubby mosark are rather small
and not very sensitive, while their chemical sense is superb.
Another way in which the chubby mosarks distinguish themselves is in their geographical range, which extends further north than any other marine mosasaur.
Although they winter in the warm waters off the coast of Florida, chubby mosasaurs spend the summer months rearing their pups in the Gulf of St. Lawrence.
This behavior is quite useful, since the habitat is devoid of competing mosasaurs, and the native pods of selkies make a tasty snack for the larger reptiles.
However, the northern water, although made bearable by the Gulf Stream, are still frigid to the coldblooded mosasaurs, and so chubby mosarks must
produce internal "coats" of insulating blubber, the source of their name.
(fig. 12) Sakhala, Carcharosaurus velox (Great Barrier Reef)
The Sakhala is a small (3 m long) and swift sharklike mosasaur that lives in the Great Barrier Reef. Though it mainly eats small fish and cephalopods, it may
attack anything smaller than a meter across if it looks edible.
(fig. 13) Nodens, Nodens incredibilis (Great Barrier Reef)
Ironically the largest known saurocete was not first discovered in the sea, but on dry land. During the first years of spexploration, some of the spexplorers
studying seaside ecosystems came across a gargantuan rotting hulk that had been washed ashore. It 18 meters long and was easily recognized as a
lizardwhale, but as the spexplorers lacked the appropriate equipment to transport that tonnage of meat, and the carcass was in such an advanced state of
decomposition that a further analysis was impossible to make at the time. The remains were hastily measured and photographed, and later some of the
skeletal remains were retrieved. These fragments became the holotype specimen of Nodens incredibilis.
Later, several other Nodens skeletons were discovered, and the largest of these, consisting of little more than a skull measuring over 4 meters long, lead to an
estimate of the adult size of Nodens, some 20 meters long, making it longest known marine vertebrate on Spec. It still took some time before the first verified
eyewitness sighting of a living specimen, but through a lucky coincidence, a group of marine biologists happened to be near a Nodens mating area, and
managed to film the animals both above and under water.
The film revealed that much of the forequarters of the giant lizardwhales were covered in curious looking scars, some resembling those left by giant squid
tentacles on sperm whales and others more unusual in appearance. It was deduced that the main diet of Nodens consisted of giant cephalopods, but the
peculiar scars lead to some dispute over what had caused them. Some claimed the lesions were bitemarks of some kind, while others blamed the infamous
great ktulu, which was reported as having feeding tentacles ending in handlike extensions covered in wicked hooks. A photograph of a large Nodens
individual with a severed end of a tentacle ending in just such fingerlike extensions still stuck on its skin only helped to fuel the controversy.
While the actual hunting and feeding of Nodens is yet to be observed, we do know that they are solitary most of the year and find their prey in the murky
depths of the ocean teeming with myriads of exotic cephalopod species. These saurocetes seem to fill the niche of HE sperm whales, although we can only
speculate at the differences in their hunting strategies. Despite having eyes not much larger than a human head, they are known to have a keen vision
especially in the dark. It is worth noting that Nodens are much more likely to move close to the surface at night than during the day.
While Nodens seemingly has a lot in common with mosarks, the latest analysis places it closest to nauticratisaurs. Though reports of Nodens individuals
longer than 20,5 meters are unverified, it still holds the record of the largest known mosasaur, being more massive (though not quite as long) as the leviathan.
Longtailed lizardwhales are a common species that form large schools off the western
coast of North America. They feed on a variety of small fish and cephalopods.
(fig. 13) Longtailed lizardwhale Naucratisaurus gracilis (Pacific)
A
close relative of the longtailed lizardwhale, the 45 meter long
azure lizardwhale forms large pods off the in the warm waters of the
Gulf Stream.
(fig. 14) Azure lizardwhale Naucratisaurus atlanticus (Atlantic)
The saurocetacines, on the other hand, are the more streamlined lizardwhales. Some possess long snouts and closely resemble the ichthyosaurs of Earth's
past and the dolphins of our home timeline.
One of the larger saurocetaceans, the prownose lizardwhale usually lives
alone but feeding aggregations of over 50 have been sighted. There are no
teeth in the upper jaw while 1214 conical teeth of each side of the dentary.
The prownose lizardwhale feeds primarily on cehalopods, including huge
barrelfish.
(fig. 15) Prownose lizardwhale Saurocetaceus pelagios (worldwide)
This cephalopodhunting saurocetacean lives in the Indian
ocean. Though closely related to the prownose lizardwhale,
Choo's lizardwhales rarely grow larger than 7 meters long.
These animals greatly resemble the Mesozoic ichtyosaurs,
which at first caused some confusion among the first
explorers of Spec.
(fig. 16) Choo's lizardwhale Saurocetaceus brianchooi (Indian Ocean)
(fig. 17) Mosapoise, Phocoenalacerta nigra (Equatorial Pacific)
The mosapoise is a 3.5 meters long saurocete specialized mostly on ammonoids, crabs, shellfishes and other hardshelled marine invertebrates it crushes with
its impressive battery of teeth.
The sawsnout lizardwhale, while clearly a saurocete, does not fit in with either the mosarks or the mosapoises. Some have allied this odd creature to apep,
the Nile mosasaur, but further studies are necessary to prove such a theory.
The sawsnout lizardwhale is undoubtedly one of the weirdest mosasaurs
in existence. Its upper jaw is disproportionally long and armed with
sharp outwardspointing teeth. Sawsnout lizardwhales use this weapon
to stun fastmoving prey and to rake out buried prey from the bottom.
(fig. 18) Sawsnout lizardwhale, Pristisaurus peculiaris(Caribbean)
Brian Choo, Daniel Bensen, and Tiina Aumala
,=Anguillacertidae=Anguillacerta sinensis (Yangtze mosasaur)
=Mosasauridae=|
| ,=Archaeosaurocetacidae=Apep aegyptianus (Nile Mosasaur)
`=|
| ,=Gigantoserpentidae=Gigantoserpens microdon (Hobb's leviathan)
| |
| | ,=Pristrix monstrum Mosark
| | ,=|
| | | | ,=C. atrox (Zahn)
| | | `=Carcharosaurus=|
| | | | ,=C. crassus (Chubby mosark)
| | | `=|
| | | `=C. velox (Sakhala)
| | ,=|
| | | |=? Nodens incredibilis (Nodens)
| | | |
| | | | ,=N. gracilis (Longtailed lizardwhale)
| | | `=Naucratisaurus=|
| | | `=N. atlanticus (Azure lizardwhale)
| | ,=|
| | | | ,=S. pelagios (Prownose lizardwhale)
| | | | ,=Saurocetaceus=|
| | | | | `=S. brianchooi (Choo's lizardwhale)
| | | `=|
| | | `=Phocoenalacerta nigra (Mosapoise)
`=Saurocetaciodea=| |
`=Saurocetacidae=|
`=Pristisaurus peculiaris (Sawsnout lizardwhale)
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