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• Critter in the news

• Ceratosauria

Puertasaurus reuili

70 Ma – giant sauropods almost to the end!

125 ft long, 100 tons! Chest alone was 16 feet in diameter

Argentinian forest, occasionally flooded by Atlantic and Pacific – no Andes yet

Discovered by Pablo Puerta and Santiago Reuil

titanosaur

Clade Ceratosauria – “horned lizard”

Fused feet, ankles, pelvic region for hind limb strength, speed, narrow gait

Four fingers

Sexual dimorphism – “robust” form with thicker limbs, longer neck and skull; “gracile” form more svelte

Some had dramatic head gear for display, perhaps intraspecific combat

Carnotaurus – “meat-eating bull”

25 feet long, 7 feet tall at hips, 1 ton

Fast runner, biter, skull built to expand to swallow prey whole like a snake

Lived in the Late Cretaceous, 70 Ma (?), in Argentina

Only 1 found, but a beauty, including skin impressions

Partially binocular vision, like some other theropods

www.karencarr.com

Coelophysis – “hollow form”

Coelophysis9 feet long, 3 feet tall at hips, 90 lbsMore than 100 specimens excavated at Ghost Ranch Quarry mass grave – evidence of social behaviorAll ages, great growth series shows age variationOnce thought to be cannibals – ate fish, small reptiles. Footprints show that they were very fastFound in Late Triassic (220 Ma) rocks in NM and AZ (Petrified Forest) representing large and small river systems, vast deserts, saline lakes, broad mudflats, and ocean shorelinesRobust and gracile forms occur in 50/50 ratio strongly indicating sexual dimorphism

More Coelophysis

Study of the eye ring comparing it to living lizards and birds shows that Coelophysis had a round (not slit) pupil, very good day vision on par with a hawk, poor night vision. Study of the skull and eye socket indicated good frontal binocular visionTrace fossil of a Coelophysis-like dinosaur shows protofeathers! Implies warm-bloodedness, perhaps all theropods had feathers

www.lucinda.net

Effigia okeeffeae

Effigia okeeffeae

Looks very dino-like, but actually a relative of Postosuchus (closer to crocodiles than dinosaurs)

From the Ghost Ranch Coelophysis Quarry

Ankle is the major give-away

Causing re-evaluation of other fragmentary Triassic remains

www.dinosaur.net.cn

www.ucmp.berkeley.edu

Dilophosaurus skeleton and left hand

Dilophosaurus – “double-crested lizard”

20 feet long, 5 feet at the hips, 1000 lb

Three specimens from Early Jurassic (190 Ma?) rocks in N AZ, found near each other, one from China, now more

No evidence for spitting, frills

Many tracks likely made by Dilophosaurus found – more evidence of social behavior

Bone structure (LAGs) indicate high growth rates

www.geocities.com/anthrosaurs/C/ceratosaurus.jpg

Ceratosaurus

Ceratosaurus

20 feet long, 1500 lb, new bigger ones

Late Jurassic, 150 Ma, Morrison Formation of Utah and Colorado

Nose horn

Dermal armor including back fin

Pretty good growth series showing significant changes from youth to adult. Young nose horn small, two halves unfused. Marker of sexual maturity