Unaysaurus is a genus of herbivorous unaysaurid sauropodomorph dinosaur. Discovered in southern Brazil, in the geopark of Paleorrota, in 1998, and announced in a press conference on Thursday, December 3, 2004, it is one of the oldest dinosaurs known. It is closely related to plateosaurid dinosaurs found in Germany, which indicates that it was relatively easy for species to spread across the giant landmass of the time, the supercontinent of Pangaea.

Classification

Upon its description, Unaysaurus was assigned to the Plateosauridae. Under this assignment, the closest relative of Unaysaurus was, counter intuitively, not from South America, but rather Plateosaurus, which lived about 210 million years ago in Germany.

Paleoecology

Unaysaurus lived between about 225 to 200 million years ago, in the Carnian or Norian age of the late Triassic period. It was found in the south of Brazil, which at the time was connected to northwest Africa. The whole world was united into the great supercontinent of Pangaea, which was just starting to divide into Laurasia in the north, and Gondwana in the south.

The Caturrita Formation has uncovered a wide variety of fauna, although the formation is also referred to as the upper portion of the Santa Maria 2 Sequence. Multiple dinosauriforms are represented in the rock of the formation, including the silesaur Sacisaurus agudoensis, and the coeval sauropodomorph Guaibasaurus candelariensis,

  • Dinosaurs of Rio grande do Sul.