A life reconstruction of Ornithomimus in its habitatDV-0057Lance Fm., Alberta

Ornithomimus

OR-nith-oh-MY-mus

"bird mimic"

DV-0057

Lived
84 to 66 million years ago, Late Cretaceous
Diet
Omnivore
Length
about 4 m (13 ft)
Group
Theropods, Ornithomimidae
Found in
United States and Canada
Named by
Marsh 1890

Field notes

About Ornithomimus

What it was like

Ornithomimus was a slender, fast-moving dinosaur that looked much like a giant, toothless ostrich, with long legs, a long neck, and a small head ending in a beak. It grew to about 4 meters (13 feet) long and was covered in feathers, though it could not fly.

Its toothless beak and long, slim hands suggest Ornithomimus was an omnivore, probably picking up plants, seeds, insects, and small animals as it foraged, more like a modern bird than a typical meat-eating dinosaur.

Its world

Ornithomimus lived from about 84 to 66 million years ago, in the Late Cretaceous, across what are now the United States and Canada, including Alberta, Montana, South Dakota, Wyoming, Colorado, and New Mexico.

It shared its world with predators such as Tyrannosaurus, Troodon, and Dromaeosaurus, the armored Edmontonia, and the horned Triceratops, one of the most common plant eaters of the time.

How it was found

Marsh named Ornithomimus in 1890. With around 26 fossil finds known, it is one of the better-represented dinosaurs of its kind, giving paleontologists a good picture of its skeleton and feathers. Its closest relatives include Gallimimus, Struthiomimus, and Archaeornithomimus, all members of the ostrich-mimic family Ornithomimidae.

The evidence

Where its fossils were found

Today

26 finds

75 million years ago

Map: C. R. Scotese, PALEOMAP

To scale

How big was Ornithomimus?

0 m1 m2 m3 m4 m
Ornithomimus: about 4 m (13 ft) · Person: 1.8 m (6 ft)Silhouette: typical theropod shape

Lived alongside

Found in the same rock formations.

Close relatives

Other members of Ornithomimidae.

Sources: Paleobiology Database, WikidataNamed in: O. C. Marsh. 1890. Description of new dinosaurian reptiles. The American Journal of Science, series 3 39:81-86