Zupaysaurus

Zupaysaurus was a medium-sized predatory dinosaur that lived during the Late Triassic period in what is now north-western Argentina. Known from a nearly complete skull alongside portions of the neck, hip, and hindlimb, it represents a crucial early branch of the neotheropod radiation. Adults reached approximately four metres in total length, roughly the mass of a large modern boar or small horse. It hunted on slender hind legs, possessing sharp, serrated teeth suited to slicing flesh. When first described, scientists believed Zupaysaurus possessed a pair of thin bony crests along its snout, similar to Dilophosaurus, though subsequent re-examination demonstrated that these displaced bones were actually delicate cervical ribs. It was among the apex terrestrial predators of its environment, likely sharing the semi-arid river valleys with early sauropodomorphs and aetosaurs before the Triassic-Jurassic extinction event rearranged terrestrial food webs.

Originally thought to sport parallel skull crests like Dilophosaurus, restudy showed these were misplaced neck ribs.

Where and when

Zupaysaurus lived in the Late Triassic, from 208.5 to 201.3 million years ago (Rhaetian age). Its remains come from Argentina, in the Los Colorados Formation.

The numbers

Length 4.3 m (estimates run from 4 to 4.5 m). Mass about 190 kg. Hip height about 1.2 m. That is 2.5 human-lengths, or 0.38 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Zupaysaurus with a bus Place on the timeline