Vertebrate Amniotes: MammalsExercise 22

Goals for today

• Learn to recognized the different anatomical, physiological, and behavioral adaptations of mammals

• Learn about the subclasses of mammals

Extinct

Class Mammalia

Hallmark characteristics of birds:1. Presence of hair (endothermy)2. Mammary glands3. 3 inner ear bones 4. Dentary-squamosal jaw articulation5. Heterodont dentition (varied teeth)6. Presence of pinnae (external ears)7. Diaphragm and 4-chambered heart8. Mammalian brain with characteristic

neocortex to regulate endothermic and circulatory systems

Mammals

http://www.youtube.com/watch?v=_YSCLSFm2eA

Subclass MonotremataCharacteristics

• Echidnas and Platypus• Most primitive extant

mammals• Lay eggs• Mammary glands lack

nipples (pezones)• 3 living species are highly

specialized, toothless

Photos from Arkive

Platypus: Cool facts! The platypus is one of the few mammals to produce venom. Males have a pair of spurs on their hind limbs. The male's pair of spurs spits out a cocktail of poisons that, while excruciatingly painful, is not lethal to most animals. Unlike snake venom, there appears to be no necrotic component in the Platypus' venom - although some muscle wastage has been observed in cases of envenomation in humans, it is likely that this is due to the inability to use the limb while the effects of the venom persist

Subclass Metatheria-MarsupialsCharacteristics• Young complete development in pouch-marsupial• Maximum dental formula: 5/4, 1/1, 3/3, 4/4• More complex limb musculature• Angle of jaw bends inward• 330 species in Neotropics, Australian region

Subclass Metatheria-Marsupials

Monito del Monte

Wombat

Koalas

Zorro pelon Demonio de Tasmania

Kaguros

Marsupials: Cool facts! Only living marsupial with a rudimentary placenta: Bandicoots

The embryos of bandicoots, unlike other marsupials, form a placenta-like organ that connects it to the uterine wall. The function of this organ is probably to transfer nutrients from the mother; however the structure is small, compared to those of the Placentalia. Wikipedia

Arkive: Golden Bandicoot

Subclass Eutheria, the placental mammalsCharacteristics

• Extended gestation with complex placenta

• Maximum dental formula: 3/3, 1/1, 4/4, 3/3

• Morphologically very diverse

• 5100 species, worldwide

Mammal Locomotion

• Aquatic animals swim;• Volant animals fly. • Cursorial animals (cursors) run rapidly and

for long distances. • Scansorial animals are climbers; in the

extreme, they are arboreal, spending most of their lives in the trees.

• Hoppers are termed saltatorial. If they use their hindlimbs only and in a fast succession of hops, they are said to be ricochetal.

• Fossorial forms are diggers, usually living in burrows.

Cursorial

Scansorial

Several terms describe how and where an animal moves

Fossorial

Mammal LocomotionLimbs are drastically modified to different ends in various groups of mammals. One way to increase stride length is to run on the tips of the toes

Puerto Rican Mammals

The present-day native terrestrial mammal fauna of Puerto Rico is composed of only 13 species, all of which are bats. Eighteen marine mammals, including manatees, dolphins and whales, occur in Puerto Rico.

Puerto Rican Hutia Isolobodon portoricensis EX

Trichechus manatusVulnerable

Red Fruit Bat Stenoderma rufum VU

A few examples

Examples of Introduced mammalsMacaques and squirrel monkeys(Mono pata y Mono Rhesus)

Black Rats, Norway rats, house mouse

Small Asian Mangoose brought to control the rats in sugar plantations-failed and contributed to the decline of several bird species.

Others include cats, dogs, pigs, etc

Most ‘diverse’ mammal groups: bats and cetaceans

Marine Mammals Bats

Fishing batHumpback whale

18 species 13 species

Bats of Puerto RicoExtant bats of Puerto Rico belong to five families (Noctilionidae, Mormoopidae, Phyllostomidae, Vespertilionidae, and Molossidae) and include a total of 13 species, of which six subspecies are endemic to the archipelago.

Jamaican Fruit-eating Bat (Eng.), Murcielago Frutero (Sp.), Artibeus jamaicensis (Sci.), native, Puerto Rico, Greater and Lesser Antilles, Bahamas, Mexico, Central America, Paraguay and Brazil.

https://www.youtube.com/watch?v=t9CuO8qefY0

Marine Mammals of Puerto RicoArguably the most famous of aquatic mammals occurring in Puerto Rican waters is the Antillean Manatee (Trichechus manatus manatus) which is listed as vulnerable by the IUCN. The archipelago's waters are one of the species' main breeding areas.

The name manatí comes from the Taíno, a pre-Columbian people of the Caribbean, meaning "breast"

ManateesThere are three accepted living species of Trichechidae, representing three of the four living species in the order Sirenia: • the Amazonian manatee (Trichechus inunguis), • the West Indian manatee (Trichechus manatus), • and the West African manatee (Trichechus senegalensis).

Manatees• Manatees are herbivores and eat over 60 different plant species,

such as mangrove leaves, turtle grass, and types of algae.

• Manatees have few natural predators. Nevertheless, sharks, crocodiles and alligators have been known to prey on manatees from time to time. Overall, however, predation does not present a significant threat to the survival of any manatee species.

http://www.youtube.com/watch?v=p7txP9MOCqs&feature=related

ManateesThe main causes of death for the sea cows are human-related issues, jet skies, engine propels

ManateesThey emit a wide range of sounds used in communication, especially between cows and their calves. Adults communicate to maintain contact and during sexual and play behaviors. Taste and smell, in addition to sight, sound, and touch, may also be forms of communication.

Listen to manatee sounds here

http://www.savethemanatee.org/audio.htm

Marine Mammals of Puerto RicoPuerto Rico's waters are also an important breeding site for the Humpback whale during the Northern Hemisphere's winter. Humpback whale watching is a popular tourist attraction in the municipality of Rincón in western Puerto Rico.

Listen humpback whales here

http://www.oceanmammalinst.org/songs.html

Other native marine mammals in Puerto Rico

Bottlenose dolphins

Common dolphins

Atlantic spotted dolphins Killer whales

Cuvier’s beaked whale

Whaling

Whaling is the hunting of whales mainly for meat and oil. Its earliest forms date to at least 3000 BC. As technology increased and demand for the resources remained, catches far exceeded the sustainable limit for whale stocks. In the late 1930s more than 50,000 whales were killed annually[2] and by the middle of the century whale stocks were not being replenished. In 1986 the International Whaling Commission (IWC) banned commercial whaling so that stocks might recover.

Dolphinarios• Love to see dolphins in captivity? swim with them when you

visit hotels, aquariums, theraphy centers, and dolphinarium. Do you know where they come from? Watch The Cove to find out and read this web site to get inform.

http://www.humanesociety.org/issues/captive_marine/

Japan

Solomon Island

http://www.pbs.org/wnet/nature/episodes/the-dolphin-defender/dolphin-captures-past-present-and-future/809/

http://www.youtube.com/watch?v=4KRD8e20fBo

Tdoay: Rat Skeleton