Abelisaurus

Abelisaurus is the foundational member of the Abelisauridae, a successful group of predatory ceratosaurs that dominated the Southern Hemisphere throughout the Cretaceous. Discovered in Patagonia by museum director Roberto Abel, the genus is known primarily from a single incomplete skull measuring about eighty-five centimetres in length. This skull reveals large openings called fenestrae, which reduced its weight, as well as a heavily textured bone surface that likely supported keratinous sheaths or rugose skin. Because no postcranial bones have been identified with certainty, its overall body proportions are inferred from better-known relatives such as Carnotaurus and Aucasaurus. These comparisons suggest a stoutly built biped between seven and nine metres long, with vestigial arms and powerful running legs, adept at tackling herbivorous ornithopods and titanosaurian sauropods across ancient South American floodplains.

It gives its name to the entire abelisaurid family, characterized by deep snouts and tiny forelimbs.

Where and when

Abelisaurus lived in the Late Cretaceous, from 83.6 to 70.6 million years ago (Campanian age). Its remains come from Argentina, in the Anacleto Formation.

The numbers

Length 8 m (estimates run from 7 to 9 m). Mass about 1.9 t. Hip height about 2.5 m. That is 4.7 human-lengths, or 0.71 of a double-decker bus. These are estimates from fragmentary remains; fields marked estimated by the site are length, mass, first ma, last ma, hip height.

Compare Abelisaurus with a bus Place on the timeline