HowStuffWorks Dinosaurs Guide  Tags: animal animals history howstuffworks dinosaur dinosaurs prehistoric fossil archaeology  

The ornithomimid, Anserimimus, has the name "goose mimic." Learn more about the Anserimimus, Late Cretaceous dinosaurs and dinosaurs of all eras.

Avimimus ('bird mimic') was a small, lightly built theropod from the Upper Cretaceous Djadokhta Formation of Mongolia. Learn more about the Avimimus and other Late Cretaceous dinosaurs.

Deinocheirus ("horrible hand") is a fascinating animal. Its front arms and three-fingered hands are nearly eight feet long. Learn more about the Deinocheirus, Late Cretaceous dinosaurs and dinosaurs of all eras.

Lufengosaurus was a sauropod that measured about 20 feet in length and was a close relative of Plateosaurus. There are complete skeletons of this dinosaur, but it has not been fully described. What else is known about this dinosaur?

Gallimimus ("chicken mimic") was the largest of the ornithomimids (the "ostrich dinosaurs") known. It has been found only in the Late Cretaceous Nemegt Formation of Mongolia. Learn more about the Gallimimus and other Late Cretaceous dinosaurs.

The Ornithomimus has been found mainly in the Late Cretaceous Judith River and Horseshoe Canyon Formations of Alberta, but less-complete specimens have been found in the western United States as well.

Orodromeus is a recently discovered dinosaur and one of the most spectacular. Orodromeus (the name means 'mountain runner') was only about 6 1/2 feet long as an adult.

Othnielia is a smaller dinosaur that wasn't named until recently. It probably survived on a diet of plants and small insects. The limbs also suggest that this dinosaur would have been a good runner.

An almost complete skull and most of the skeleton were found for Prenocephale. It was collected during the Joint Polish-Mongolian Expeditions to the Gobi Desert. The animal was named and described in 1974.

Struthiomimus ("ostrich mimic") is the best known of all the ornithomimids. A complete skeleton, which is now displayed at the American Museum of Natural History, was collected from the Judith River Formation of Alberta. Its name points to how similar its

Troodon was described in 1856 by Joseph Leidy on the basis of a single small tooth. It was one of the first North American dinosaurs described. Learn more about the Troodon and other Late Cretaceous dinosaurs.