Temporal range: Late Cretaceous
|An artist's illustration of Ornithomimus velox based on the 2015 feather fossil|
| †Ornithomimus velox|
Ornithomimus (pron.: /ˌɔrnɨθɵˈmaɪməs/; "bird mimic") is a genus of ornithomimid dinosaur from the Late Cretaceous Period (70-65 mya) of what is now North America. In 1890 Ornithomimus velox was named by Othniel Charles Marsh on the basis of a foot and partial hand from the Maastrichtian Denver Formation. Another seventeen species have been named since. Most of these have subsequently been assigned to new genera or shown to be not directly related to Ornithomimus. The best material of species still considered part of the genus has been found in Canada, representing the earlier Edmontonian-age Ornithomimus edmontonicus Sternberg 1933, known from several skeletons. However, on some of these the new genus Dromiceiomimus including Dromiceiomimus brevitertius (Parks 1926) has been based, causing taxonomic problems of priority and identity that are still unresolved. Ornithomimus was a swift bipedal animal covered in feathers, and was equipped with a small toothless beaked head, that may indicate an omnivorous diet.
Like other ornithomimids, Ornithomimus is characterized by a foot with three weight-bearing toes, long slender arms and a long neck with a birdlike, elongated, toothless, beaked skull. It was bipedal and superficially resembled an ostrich, except for its long tail. It would have been a swift runner. It had very long limbs, hollow bones, and a large brain and eyes. The brains of ornithomimids were large for dinosaurs, but this may not necessarily be a sign of greater intelligence; some paleontologists think that the enlarged portions of the brain were dedicated to kinesthetic coordination. Their hands are remarkably sloth-like in appearance, which led Henry Fairfield Osborn to suggest that they were used to hook branches during feeding. Ornithomimus differs from other ornithomimids, such as Struthiomimus, in having a short back, long slender forearms, very slender, straight hand and foot claws and in having metacarpals and fingers of similar lengths. The three Ornithomimus species today seen as possibly valid, differ rather in size. In 2010 Gregory S. Paul estimated the length of O. edmontonicus at 3.8 metres, its weight at 170 kilograms (370 lb). One of its specimens, CMN 12228, preserves a femur (thigh bone) 46.8 centimetres (18.4 in) long. O. sedens was by Paul estimated at 4.8 metres and 350 kilograms (770 lb). O. velox, the type species of Ornithomimus, is based on material of a much smaller animal. Whereas the holotype of O. edmontonicus, CMN 8632, preserves a second metacarpal 84 millimeters long, the same element with O. velox measures only 53 millimeters.
In 1996, 2008 and 2009, three Ornithomimus edmontonicus specimens, two adults and a juvenile, were found with remains of pennaceous feather shafts on the lower arm or with impressions of up to five centimetres long primitive feathers in the form of hair-like filaments covering the rump, legs and neck. The fact that the feather imprints were found in sandstone, previously thought to not be able to support such impressions, gives new possibilities for future feather finds. A study describing these fossils in 2012 concluded that O. edmontonicus was covered in plumaceous feathers at all growth stages, and that only adults had pennaceous wing-like structures, suggesting that wings may have evolved for mating displays. A fourth feathered specimen of Ornithomimus, this time from the lower portion of the Dinosaur Park Formation, was described in October, 2015 by Aaron van der Reest, Alex Wolfe, and Phil Currie. It was the first Ornithomimus specimen to preserve the feathers along the tail. The feathers, though crushed and distorted, bore numerous similarities with those of the modern ostrich, both in their structure and distribution on the body. Skin impressions were also preserved in the 2015 specimen, which indicated that from mid-thigh to the feet, there was bare skin devoid of scales, and that a flap of skin connect the upper thigh to the torso. This latter structure is similar to that found in modern birds, including ostriches, but was positioned higher above the knee in Ornithomimus than in birds.
In Popular Culture
- Ornithomimus appears in Disney's Fantasia where it has no feathers and its' tail dragging on the floor.
- It appeared in the 1969 Stop Motion Sci Fi Film The Valley of Gwangi.
- It appeared in the 1981 short film 64,000,000 Years Ago.
- Ornithomimus appear in the original The Land Before Time, most prominently being featured during the birth of Littlefoot, where one attempts to steal his unhatched egg, and during the Great Earthshake, where many Ornithomimus are seen fleeing amidst the chaos. They are called Clawhand in the script for the first movie.
- Ornithomimus in PBS The Dinosaurs! “Flesh on the Bones” when it was running.
- It appears in the Magic School Bus episode "The Busasaurus", lacking feathers.
- It was also in the IMAX movie, T-Rex: Back to the Cretaceous.
- It appears in When Dinosaurs Roamed America with a short covering of silky feathers on its' body (although it lacks wings and its' legs are almost completely covered, unlike the real creature).
- It appears in all episodes of Prehistoric Park where it inaccurately lacks feathers and perfers water to land.
- It appears in Dinosaur Train, being featherless minus some quills on its' head.
- It was planned to be featured in the video game Jurassic Park: Operation Genesis but got cut off.
- It is nr. 029 of the Carnivore Ones that can be created Jurassic Park III: Park Builder. It completely lacks feathers.
- It will appear in Saurian and Prehistoric Kingdom, both of which are the most accurate Ornithomimus in pop culture so far.
- Ornithomimus is a rare in Jurassic World: Alive. While it is accurately portrayed with a coat of feathers, it is shown inaccurately to be able to pronate it's hands.