Teyujagua was a small, semiaquatic archosauromorph reptile that lived in Brazil during the Triassic period. It is known from a well-preserved skull, and probably resembled a crocodile in appearance. It was an intermediary between the primitive archosauromorphs and the more advanced Archosauriformes. Its genus name Teyujagua is derived from Teyú Yaguá, a lizard in Guarani mythology with a dog-like head, and the species name paradoxa means unusual, strange'.