Einiosaurus

Einiosaurus was a medium-sized centrosaurine ceratopsid that lived in western North America during the Late Cretaceous epoch. Reaching about five metres in length and weighing over a tonne, it was roughly comparable in bulk to a modern black rhinoceros. It is renowned for its bizarre nasal horn, which grew forward and downward in mature individuals, terminating in a rounded tip. Additionally, its neck frill carried two large, upright bony spikes curving backward. Found in massive bonebeds containing hundreds of individuals in Montana, Einiosaurus almost certainly lived and travelled in gregarious herds, grazing on ferns, cycads, and conifers across coastal plains.

Its nasal horn curved sharply forward and downward like a giant can-opener.

Where and when

Einiosaurus lived in the Late Cretaceous, from 75 to 74 million years ago (Campanian age). Its remains come from United States, in the Two Medicine Formation.

The numbers

Length 4.8 m (estimates run from 4.5 to 5 m). Mass about 1.5 t. Hip height about 1.8 m. That is 2.8 human-lengths, or 0.43 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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