In the lead, it was announced 2004-12-03--> The name Unaysaurus comes from the word unay (u-na-hee), meaning "black water" in the local Tupi language, which in turn refers to Agua Negra (also "black water"), the Portuguese name for the region where the fossils were found.
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.