TEYUWASU

The remains that would become Teyuwasu (a thighbone and shin) were referred by Friedrich von Huene to his "Triassic aetosaur" Hoplitosaurus in 1938, which was problematic for a couple of reasons: (1) Lucas had given the name Hoplitosaurus—"armoured lizard"—to an ankylosaurian dinosaur 36 years earlier, so von Huene conjured up Hoplitosuchus—"armoured crocodile"—as a replacement name in 1942, and (2) the only remains that the now named Hoplitosuchus can confidently lay claim to are a couple of armour plates for which the name was raised.

In his sensationally titled 1999 paper "new dinosaurian "rescued" from the Brazilian Triassic", Edio-Ernst Kischlat announced that the previously-mentioned leg bones actually belonged to a "robust" dinosaur which he named Teyuwasu, but he didn't say how robust. In fact, his entire review was a bit sketchy and half-hearted, and in a symposium abstract which does not constitute a published work, so many palaeontologists were far from convinced of Teyuwasu's validity. Some experts thought it was a bona fide dinosaur, while others did not.

Garcia, Müller and Dias-da-Silva pitched their tent in the former camp, believing Teyuwasu belonged in Herrerasauridae, which may or may not be dinosaurs of the theropod persuasion, depending on which school of scientific thought you subscribe to. However, they also found Teyuwasu to be indistinguishable from another Brasilian herrerasaurid, and its fossils became the first to be recognized as referable to Staurikosaurus for almost half a century when they sank the former as a junior synonym of the latter in 2019.