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• Ornithomimus

• Othnielosaurus

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Ornithomimus dates from the latest Cretaceous (65 million years ago) of the Rocky Mountain region. This diorama depicts the final days of the “Age of Reptiles” when the giant dinosaur lineages finally went extinct, almost certainly due to the collision of an asteroid or comet with the Earth. The giant horned dinosaur,  Triceratops (“Three-horned face”, Tri-SER-a-tops), wanders in the background, while the small mammals  Stygimys (STI-ji-mees),  Cimolestes (SIM-o-LESS-tees) and  Mesodma (Mee-ZOD-ma), and the crocodilian  Leidyosuchus (LIE-dee-o-SOOK-us), stake their claim to the planet. Interestingly, when  Ornithomimus was named in 1890, it was on the basis of its bird-like feet and legs, not on the ostrich-like neck and toothless beak now known to have been present. New fossils from China and Mongolia show that ornithomimid dinosaurs brooded their eggs in nests and had feathers! This is a remarkable demonstration of the predictive power of comparative anatomy and of the bird-dinosaur hypothesis.