Teratophoneus

Teratophoneus was a distinctive tyrannosaurine theropod discovered in southern Utah's Kaiparowits Formation. Thriving roughly 76 million years ago, it measured about six metres in length and weighed over a tonne. It possessed a characteristically short, blunt snout, steep skull profile, and robust jaw anatomy that differed from its long-snouted northern contemporaries such as Gorgosaurus. A bonebed containing several specimens of varying ages dying together in a single river system suggests they may have lived and hunted cooperatively in family groups.

A mass mortality site preserved multiple individuals together, hinting at gregarious pack behaviour.

Where and when

Teratophoneus lived in the Late Cretaceous, from 77 to 75 million years ago (Campanian age). Its remains come from United States, in the Kaiparowits Formation.

The numbers

Length 6.3 m (estimates run from 6 to 6.5 m). Mass about 1.2 t. Hip height about 2 m. That is 3.7 human-lengths, or 0.56 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Teratophoneus with a bus Place on the timeline