Deinonychus antirrhopus is a genus of dromaeosaurid theropod dinosaur. It lived during the early Cretaceous Period, about 115–108 million years ago. Fossils have been recovered from the U.S. states of Montana, Utah, Wyoming, and Oklahoma. The species name means ‘counter balance’, which refers to Ostrom’s idea about the function of the tail.
About Deinonychus in brief
Deinonychus antirrhopus is a genus of dromaeosaurid theropod dinosaur. It lived during the early Cretaceous Period, about 115–108 million years ago. Fossils have been recovered from the U.S. states of Montana, Utah, Wyoming, and Oklahoma, in rocks of the Cloverly Formation, Cedar Mountain Formation and Antlers Formation. Teeth found in the Arundel Clay Facies, of the Potomac Formation on the Atlantic Coastal Plain of Maryland may be assigned to the genus. The species name means ‘counter balance’, which refers to Ostrom’s idea about the function of the tail. DeinonyChus remains have been found closely associated with those of the ornithopod Tenontosaurus, suggesting they were hunted, or at least scavenged upon, by Deinoneychus. The first remains were uncovered in 1931 in southern Montana near the town of Billings. A little more than thirty years later, paleontologist John Ostrom led an expedition from Yale’s Peabody Museum of Natural History which uncovered more skeletal material. Since then, more than 1,000 bones have been discovered. At least three individuals have been identified as the type specimen. The remaining specimens were catalogued in fifty separate entries at Yale’s Peabody Museum of Natural History, although they could have been from as few as three individuals as well as a few separate individuals. The type specimen of DeinONYchus was restricted to the complete right foot and partial right foot of the left foot of a single individual, and that individual was never identified.
The remains of the same individual have been catalogued as two separate entries in 50 separate entries, although the remaining remains were cataloged in fifty different entries at PeabODY Museum of Natural History, although it is impossible to determine their exact location. The fossil YPM 5205 preserves a large, strongly curved ungual. In life, archosaurs have a horny sheath over this bone, which extends the length. Ostrom noted the small body, sleek, horizontal posture, ratite-like spine, and especially the enlarged raptorial claws on the feet, which suggested an active, agile predator. This species, which could grow up to 3. 4 meters long, was found in Montana and Wyoming. It is thought to have lived between 115 and 108 million years ago, during the late Aptian through early Albian stages of the early Cretaceous period. It has been described as a small carnivorous dinosaur close to a Tenontosaurs skeleton, but encased in lime difficult to prepare. A fossil of the very closely related Velociraptor mongoliensis has an articulated tail skeleton that is curved laterally in a long S-shape. This suggests that, in life, the tail could bend to the sides with a high degree of flexibility. It was named Microvenator.