Leyesaurus (after the Leyes family that discovered it); pronounced LAY-eh-SORE-us
Woodlands of South America
Late Triassic (200 million years ago)
Size and Weight:
About 8 feet long and a few hundred pounds
Low-slung body; long neck and tail
Announced to the world in 2011, based on the discovery of a fossilized skull and bits and pieces of leg and backbone, Leyesaurus is the latest addition to the prosauropod roster. (Prosauropods were the slender, plant-eating dinosaurs of the Triassic period whose closest cousins evolved into the gigantic sauropods of the Jurassic and Cretaceous.) Leyesaurus was comparatively more advanced than the much earlier Panphagia, and about on a par with the contemporary Massospondylus, to which it was closely related. Like other prosauropods, the slender Leyesaurus was probably capable of sprinting on its hind legs when pursued by predators, but otherwise spent its time on all fours, nibbling low-lying vegetation.