Although several dinosaurs have been classified as plateosaurids over the years, a 2007 study by Adam M. Yates found only Plateosaurus and Unaysaurus valid plateosaurids.
Gravisauria split off in the Early Jurassic, around the Pliensbachian and Toarcian, 183 million years ago, and Aquesbi thought that this was part of a much larger revolution in the fauna, which includes the disappearance of Prosauropoda, Coelophysoidea and basal Thyreophora, which they attributed to a worldwide mass extinction.