Deinocheirus

Cretaceous-aged dinosaur fossil localities of Mongolia

Deinocheirusbcn

Deinocheirus Skull

Deinocheirus Scale

Hypothetical Deinocheirus

Deinocheirus (terrible hand) is a genus of large ornithomimosaur that lived during the Late Cretaceous period, approximately 70 million years ago, in what is now Mongolia. It is known from a few specimens, the most complete of which include a pair of massive arms, from which it gets its name, with large, clawed hands. Deinocheirus was one of the largest ornithomimosaurs, measuring up to 11 meters (36 ft) in length and weighing around 6.4 tonnes.

Description

Deinocheirus is distinguished by its large size, long neck, broad, duck-like bill, and the large, clawed hands that were first discovered. Its body was bulky, with a wide ribcage, and it had a relatively long tail. The legs were robust and ended in four-toed feet. The most striking feature of Deinocheirus was its arms, which were among the longest of any bipedal dinosaur, measuring over 2.4 meters (8 ft) in length.

Discovery and Naming

The first fossils of Deinocheirus were discovered in 1965 by a Polish-Mongolian paleontological expedition in the Nemegt Basin of Mongolia. The genus was named and described in 1966 by Evgeny Khrushchyov and Zofia Kielan-Jaworowska. The name Deinocheirus means "terrible hand", referring to the size and strength of its forelimbs. Initially, only the arms and some other fragmentary remains were known, leading to much speculation about the nature of this dinosaur.

Further expeditions and studies have since uncovered more complete specimens, revealing the unusual body shape and lifestyle of Deinocheirus. These findings have helped paleontologists understand that it was a large, omnivorous dinosaur with a diet that likely included both plants and small animals.

Classification

Deinocheirus is classified within the Ornithomimosauria, a group of theropod dinosaurs that were characterized by their bird-like bodies and, in many cases, a toothless beak. It is considered one of the most derived members of this group, showing adaptations for a more omnivorous diet compared to its more strictly herbivorous or carnivorous relatives.

Paleobiology

The unique morphology of Deinocheirus suggests a variety of feeding behaviors. The shape of its skull and jaws indicates that it could have had a diet similar to that of modern ducks, sifting through water and mud for plants and small invertebrates. The large claws may have been used for digging or pulling down branches to reach leaves.

Paleoecology

Deinocheirus lived in a wet, floodplain environment, as indicated by the sedimentary rocks of the Nemegt Formation where its fossils were found. This habitat was rich in other dinosaur species, including the tyrannosaurid Tarbosaurus, the hadrosaurid Saurolophus, and various other theropods, ornithopods, and ceratopsians. The diversity of the fauna suggests a complex ecosystem in which Deinocheirus occupied a niche as a large omnivore.

See Also

• Ornithomimosauria
• Cretaceous
• Dinosaur
• Paleontology