Unaysaurus

Unaysaurus is a genus of early herbivorous sauropodomorph dinosaur that lived in southern Brazil during the Norian stage of the Late Triassic Period. Discovered in Rio Grande do Sul, the remarkably well-preserved fossil includes an almost intact skull alongside partial neck, limb, and shoulder elements. Measuring approximately two and a half metres in length, Unaysaurus was an agile, bipedal browser with a body weight comparable to that of an adult human. Phylogenetic analysis places it close to European plateosaurids, indicating that early sauropodomorph lineages moved freely across Pangaea before continental separation took hold. It used serrated, leaf-shaped teeth to crop ferns and seed-bearing plants, helping fill the mid-sized herbivore niche of its ancient ecosystem.

It was the first plateosaurid identified from South America, closely resembling European forms.

Where and when

Unaysaurus lived in the Late Triassic, from 225.4 to 221 million years ago (Norian age). Its remains come from Brazil, in the Caturrita Formation.

The numbers

Length 2.5 m. Mass about 84 kg. Hip height about 0.8 m. That is 1.5 human-lengths, or 0.22 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

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