Sellosaurus

Valid species

The taxonomic history of Plateosaurus is "long and confusing" and a "chaotic tangle of names". As of 2019, only three species are universally accepted as valid: the type species P. trossingensis, P. longiceps, and P. gracilis (which was previously assigned to its own genus, Sellosaurus). Moser performed the most extensive and detailed investigation of all plateosaurid material from Germany and Switzerland, concluding that all Plateosaurus and most other prosauropod material from the Keuper stems from the same species as the type material of Plateosaurus engelhardti. However, this is problematic due to the undiagnostic state of the lectotype. Moser considered Sellosaurus to be the same genus as Plateosaurus, but did not discuss whether S. gracilis and P. engelhardti belong to the same species. Palaeontologist Adam Yates of the University of the Witwatersrand cast further doubt on the generic separation. He included the type material of Sellosaurus gracilis in Plateosaurus as P. gracilis and reintroduced the old name Efraasia for some material that had been assigned to Sellosaurus. In 1926, von Huene had already concluded the two genera were the same.