What is Unaysauridae?

The most inclusive clade including Unaysaurus tolentinoi, but not Plateosaurus engelhardti nor Saltasaurus loricatus. Unaysauridae is a proposed group of early sauropodomorph dinosaurs from the Late Triassic of Brazil, though its validity remains uncertain: the clade is defined by just two features — a distinctive expansion on the ankle bone and a small opening in the upper jaw — yet neither trait is present in all of the animals traditionally assigned to it. Because these supposed diagnostic characters are inconsistent or missing, some palaeontologists question whether Unaysauridae is a natural group at all and instead place its members within the broader, more stable Plateosauridae.

Click here to view Dinochecker's A-Z list of unaysaurids. Unaysauridae is derived from the Tupi word "unay" (pronounced yoo-na-hee, meaning "black water", which in turn refers to Agua Negra [also "black water"], the Portuguese name for the region where the fossils were found), the Greek "sauros" (lizard) and the Latin "-idae" (family). This group is named after the flag-bearer Unaysaurus tolentinoi.