Pentaceratops

Pentaceratops was a large chasmosaurine ceratopsid that inhabited the subtropical floodplains of the American Southwest during the Late Cretaceous, around 74 million years ago. Measuring around 6 metres long and weighing roughly 3 tonnes, its skull was topped by an exceptionally tall, upright parietal frill that ended in a distinct heart-shaped notch. Its name means five-horned face, referring to its nasal horn, two long forward-curving brow horns, and two sharply pointed cheek spikes formed by projecting jugal bones. The vast frill contained large windows that kept it relatively lightweight, serving primarily as an impressive visual billboard for courtship and threat displays. Known from numerous skulls and skeletons in New Mexico's Kirtland and Fruitland Formations, Pentaceratops grazed on dense ground foliage while coexisting with duck-billed hadrosaurs and tyrannosaurid predators.

Despite its name, two of its 'horns' were actually prominent, pointed cheekbones called epijugals.

Where and when

Pentaceratops lived in the Late Cretaceous, from 75 to 73 million years ago (Campanian age). Its remains come from United States, in the Kirtland Formation.

The numbers

Length 6 m (estimates run from 5.5 to 6.5 m). Mass about 3.2 t. Hip height about 2.1 m. That is 3.5 human-lengths, or 0.54 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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