Tylocephale Tylocephale

Tylocephale (meaning “swollen head”) is a genus of pachycephalosaurid dinosaur, a group of dome-headed, herbivorous ornithischians, that lived during the Maastrichtian stage of the Late Cretaceous in what is now Mongolia. It is known from a partial skull and associated mandible that were unearthed in 1971 by a Polish-Mongolian Expedition to the Barun Goyot Formation of the Gobi Desert. The specimen was described in 1974 by Polish paleontologists Teresa Maryańska and Halszka Osmólska as a new genus and species.

It was average-sized for a pachycephalosaur, reaching 2 m in length and 40 kg in body mass. The skull is triangular in back view, the widest point being at the jugals with an apex at the top of the dome. Tylocephale’s dome is the tallest known from a pachycephalosaur. This dome is also unusually thick and rugose on its exterior.