Buriolestes

Buriolestes is a groundbreaking early dinosaur uncovered in the Late Triassic Santa Maria Formation of southern Brazil. Despite belonging phylogenetically to the sauropodomorph branch, the lineage that eventually produced colossal long-necked herbivores like Brachiosaurus, Buriolestes was a fleet-footed, carnivorous biped. 2 metres in length and weighed less than six kilograms, making it about the size of a fox. Its jaws were armed with blade-like, backward-curving teeth with fine serrations, perfectly built for catching insects, small lizards, and early synapsids. Exceptionally complete skeletons, including intact skulls and braincases, have allowed palaeontologists to reconstruct its neuroanatomy, showing high sensory capability and sharp eyesight suited to hunting. Buriolestes conclusively demonstrated that sauropodomorphs did not originate as herbivores, but rather evolved herbivory secondarily after branching off from an ancestrally predatory dinosaurian stock.

Although an ancestor of giant herbivorous sauropods, its sharp serrated teeth prove it was entirely carnivorous.

Where and when

Buriolestes lived in the Late Triassic, from 233.2 to 230 million years ago (Carnian age). Its remains come from Brazil, in the Santa Maria Formation.

The numbers

Length 1.3 m (estimates run from 1.1 to 1.4 m). Mass about 4.2 kg. Hip height about 0.4 m. That is 0.8 human-lengths, or 0.12 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Buriolestes with a bus Place on the timeline