Ornitholestes

What it was like

Ornitholestes was a small, lightly built theropod with long, grasping hands and sharp, narrow teeth suited to catching small, quick prey such as lizards or insects. It ran on two legs and likely relied on speed and agility rather than size to catch its meals. Ornitholestes grew to about 2 meters (6.6 feet) long, including a long tail that probably helped it balance while running. The type species is Ornitholestes hermanni.

Its world

Ornitholestes lived from about 158 to 143 million years ago, spanning the Late Jurassic into the Early Cretaceous, in what is now the United States. Its fossils come from the Morrison Formation in Wyoming, a rock unit famous for giant dinosaurs such as Stegosaurus, Allosaurus, Brachiosaurus, and Diplodocus. Ornitholestes itself was far too small to challenge animals like these, and probably hunted smaller game instead.

How it was found

Osborn named Ornitholestes in 1903. Two fossil finds are known today. A hand fossil once thought to belong to Ornitholestes is now thought to belong to a different theropod, showing how new discoveries can change what scientists know even about dinosaurs found long ago.