Triodus


Triodus is an extinct genus of xenacanthidan shark that lived from the Carboniferous to the Triassic. It was a freshwater shark, and fossils have been found in the Chinle Formation and Black Prince Limestone of Arizona, the Petrified Forest Member of New Mexico and the Tecovas Formation of Texas, United States. In 2017, a new species Triodus richterae was described from the Rio do Rasto Formation of Brazil.