Article: The West Gondwanan occurrence of the hybodontid shark Priohybodus, and the Late Jurassic–Early Cretaceous age of the Tacuarembó Formation, Uruguay

Priohybodus cf. P. arambourgi is reported for the first time from the Tacuarembo Formation of Uruguay. This species is a hybodontid shark known previously only from Upper Jurassic and Lower Cretaceous deposits of Saharan Africa and the Arabian Peninsula. The material (22 isolated teeth and a dorsal fin spine) was found in a thin bone bed, associated with abundant bone fragments, scales and teeth of semionotiform fishes and theropod dinosaurs. Until now, the age of the Tacuarembo Formation has been difficult to determine because its fossil content lacked useful biostratigraphic indicators. The finding of Priohybodus cf. P. arambourgi in that unit greatly expands the palaeobiogeographic range of the species, and allows us to propose a Late Jurassic-Early Cretaceous age for the Tacuarembo Formation.