Category: Dinosaur

Deinocheirus (Die-no-ky-rus), or "Terrible Hands" is regarded as one of the most peculiar species of dinosaur. The true identity of this bizarre creature was a mystery for over four decades. However, at 36 ft long, Deinocheirus is now known to be the largest of the so-called ‘ostrich dinosaurs’. It lived in Mongolia during the Late Cretaceous, 70 million years ago.



Genera and Species

1. Genera & species

2. Characteristics

a. Size

b. Appearance & Behavior

3. History of Discovery

4. Paleoenvironment


Deinocheirus was an unusual, two-legged dinosaur with a small head, a humped back, and a long tail. The end of its skull expanded into a flattened ‘bill’ and its teeth suggest that it may have been an omnivore. The tip of its tail may have had a tuft of feathers and its body may have been covered in downy fuzz.


LENGTH: 11 meters (36 ft.)

WEIGHT: 6.36 tons (14,000 lbs.)


Many mysteries still surround this odd dinosaur. Its diet, for example, is unclear. It was probably an omnivore and ate both meat and plants. If this is the case, then it may have used its large arms and blunt claws to grab branches while feeding.

Recent material described in 2014 revealed an even more unusual dinosaur than anyone had expected! In addition to its famous "horrible" arms, it had several other unusual features, including a humped back and a stretched out head that ended in a broad bill. Lastly, Deinocheirus possessed a fused structure at the tip of its tail that consisted of several bones, much like the ‘pygostyle’ in modern birds, which supports tail feathers. This suggests that the end of Deinocheirus’ tail may have borne a tuft of feathers, with the rest of its body possibly being covered in feathers from head to toe, like some other theropods.

History of Discovery

When a pair of mysterious, giant arms were discovered in the Gobi Desert of Mongolia in 1965, they raised more questions than they answered. Polish palaeontologists described these three-clawed hands in 1970 and gave them the name Deinocheirus, which aptly means ‘terrible hand’. This dino was placed in a brand new family, Deinocheiridae, because its arms were so different from those of all other known dinosaurs. However, since the rest of the skeleton was destroyed by erosion, the nature of this enigmatic species remained uncertain for over four decades, until more complete remains were discovered in 2009.


Deinocheirus lived in the Late Cretaceous Period, in an area of Mongolia that was likely humid and contained streams, rivers, and shallow lake areas. It may have had to use its large claws to avoid becoming prey for Tarbosaurus, a Tyrannosaurus cousin that shared its environment.