Marasuchus lilloensis

 Late Triassic (236-234Ma) of Argentina. Discovered in the 1960s, it was described in 1972 (although first named Lagosuchus). It was a very small (40cm, 5kg), long-legged, bipedal animal; probably carnivorous.

Marasuchus is a very important species, as it is a dinosauriform and thus one of the closest relatives to dinosaurs, with some advanced traits (such as bipedalism and rapid running ability) that are predicted to have been passed on to the earliest dinosaurs.

Artistic interpretation of Marasuchus by John Conway