Deinocheirus

Deinocheirus was one of the most enigmatic dinosaurs ever discovered, remaining known for nearly fifty years only by a solitary pair of enormous forelimbs measuring two point four metres in length. In 2014, the discovery of new, nearly complete specimens revealed its bizarre, almost surreal appearance. Far from being an agile predator, Deinocheirus was an eleven-metre-long, colossal ornithomimosaur weighing over six tonnes. It walked on sturdy, hoof-like hind claws and sported a low hump or sail formed by elongated neural spines along its back. Its skull featured a wide, toothless, duck-like bill and a deep lower jaw. Preserved stomach contents, including fish scales and gastroliths, confirm that Deinocheirus was an omnivore that waded through marshlands and slow-moving river systems, feeding upon aquatic plants and small freshwater fish.

4-metre arms, a broad duck-like bill, and a tall hump or sail along its back.

Where and when

Deinocheirus lived in the Late Cretaceous, from 71 to 68 million years ago (Maastrichtian age). Its remains come from Mongolia, in the Nemegt Formation.

The numbers

Length 11 m (estimates run from 11 to 12 m). Mass about 6.5 t. Hip height about 4.4 m. That is 6.6 human-lengths, or 1.01 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Deinocheirus with a bus Place on the timeline