World of Dinosaurs/Allosaurus

An Allosaurus skeleton in the American Museum of Natural History.

Basics

Allosaurus means "other lizard"

Allosuarus fragilis is the state fossil of Utah

Allosaurus lived during the Jurassic Period

Anatomy

Allosaurus is a lanky meat-eating dinosaur.

Look for these features:

- furcula (wish bone, which is found in the theropod clade)

- smooth ankle and smooth hips

- ankle raised off the ground (found in derived theropods)

Phylogeny

Allosaurus is a meat-eating beasty, a theropod dinosaur.

All theropods are dinosaurs.

All dinosaurs are amniotes and all dinosaurs are tetrapods.

Biomechanics

Allosaurus have jaws that can offer a stronger bite than an alligator, but not quite as powerful as a Tyrannosaurus rex.

Fossil Record

Visit the paleobiology database, at paleodb.org

Allosaurus fossils are relatively common in Utah, including many scattered (disarticulated) skeletons at the Cleveland Lloyd Quarry in Utah.

Ecology

Allosaurus is a meat-eating dinosaur which co-occurred with Stegosaurus.

Ferns, shrubs, and trees would have been common, but flowering plants, fruit trees, or grass were NOT around yet!

Biogeography

Rocks from the Jurassic period indicate hotter, wetter conditions than we experience on Earth today.

Rocks do not show signs of ice caps near the poles, of traveling ice-bergs, or other signs of "ice house" conditions.

Allosaurus would have roamed deserts and river systems. The super-continent Pangea was splitting up throughout the Jurassic Period, adding volcanic activity, particularly along the west coast, and warm, seasonally-variable habitats.