Pisanosaurus

Pisanosaurus ( ) is an extinct genus of early dinosauriform, likely an ornithischian or silesaurid, from the Late Triassic of Argentina. It was a small, lightly built, ground-dwelling herbivore, that could grow up to an estimated long. Only one species, the type, Pisanosaurus mertii, is known, based on a single partial skeleton discovered in the Ischigualasto Formation of the Ischigualasto-Villa Unión Basin in northwestern Argentina. This part of the formation has been dated to the late Carnian, approximately 229 million years ago.

== Discovery and naming == thumb|left|Reconstructed skeleton reflecting the traditional interpretation of Pisanosaurus as an ornithischian dinosaur, Royal Ontario Museum Pisanosaurus is known from a single fragmented skeleton discovered in 1962 by Galileo Juan Scaglia at the Hoyada del Cerro Las Lajas locality (also known as Agua de Las Catas) in the Ischigualasto Formation of La Rioja Province, Argentina.