Elmisaurus

Elmisaurus was a gracile caenagnathid theropod that lived during the Late Cretaceous in what is now the Gobi Desert of Mongolia. Known primarily from hands and uniquely fused foot bones, it was closely related to North American oviraptorosaurs such as Chirostenotes. Reaching roughly two metres in length and weighing perhaps twenty kilograms, it was a lightweight, fast-running biped. Like its close kin, Elmisaurus likely bore pennaceous feathers and possessed a toothless, beak-like jaw suited for consuming an omnivorous diet of small animals, insects, seeds, and vegetation. The fusion of its metatarsal bones into a rigid unit indicates specialization for agile locomotion across river plains and dry terrain. Ongoing study of these delicate limbs continues to clarify the evolutionary connections between Asian and North American caenagnathids near the close of the Mesozoic era.

It was discovered with distinctly fused foot bones, an unusual adaptation among oviraptorosaurs that inspired its name.

Where and when

Elmisaurus lived in the Late Cretaceous, from 70.6 to 66 million years ago (Maastrichtian age). Its remains come from Mongolia, in the Nemegt Formation.

The numbers

Length 1.8 m (estimates run from 1.6 to 2 m). Mass about 21 kg. Hip height about 0.8 m. That is 1.1 human-lengths, or 0.16 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

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