Deinocheirus is a genus of large ornithomimosaur that lived during the Late Cretaceous around 70 million years ago. In 1965, a pair of large arms, shoulder girdles, and a few other bones of a new dinosaur were first discovered in the Nemegt Formation of Mongolia. In 1970, this specimen became the holotype of the only species within the genus, Deinocheirus mirificus; the genus name is Greek for “horrible hand”. No further remains were discovered for almost fifty years, and its nature remained a mystery. Two more complete specimens were described in 2014, which shed light on many aspects of the animal. Parts of these new specimens had been looted from Mongolia some years before, but were repatriated in 2014.
Deinocheirus was one of the most mysterious dinosaurs to have ever been found by paleontologists. It was originally found in 1965 in Southern Mongolia—actually, not the whole dinosaur was found but only its gigantic hands. And for the next 50 years, that is all that scientists would have of this elusive dinosaur. That is probably why its name means “terrible hand”.
When Deinocheirus was only known from the original forelimbs, its taxonomic relationship was difficult to determine, and several hypotheses were proposed. Osmólska and Roniewicz initially concluded that Deinocheirus did not belong in any already named theropod family, so they created a new, monotypic family Deinocheiridae, placed in the infraorder Carnosauria. This was due to the large size and thick-walled limb bones, but they also found some similarities with Ornithomimus, and, to a lesser extent, Allosaurus. In 1971, John Ostrom first proposed that Deinocheirus belonged with the Ornithomimosauria, while noting that it contained both ornithomimosaurian and non-ornithomimosaurian characters. In 1976, Rhinchen Barsbold named the order Deinocheirosauria, which was to include the supposedly related genera Deinocheirus and Therizinosaurus. A relationship between Deinocheirus and the long-armed therizinosaurs was supported by some later writers, but they are not considered to be closely related today.
Deinocheirus was around 30 feet long, almost 15 feet high and weighed about 6 tons. It was a bipedal dinosaur—from a species called Ornithomimids, which are sometimes called ‘ostrich dinosaurs’ and was the biggest of these dinosaurs. However, it probably didn’t move like an ostrich. Due to its large size and weight, it more than likely lumbered along and didn’t run very quickly. I
It is believed that this dinosaur was a scavenger of sorts. It is believed to have eaten a variety of different things such as fish, invertebrates, plants and maybe even insects. It probably didn’t hunt prey like a predator. However, an interesting fact about this dinosaur is that it was probably frequently hunted by tyrannosaurus dinosaurs, as bite marks on its skeleton would suggest.