Tribodus

Tribodus is an extinct genus of hybodont shark from the Romualdo Formation of northeastern Brazil. It lived during the Early Cretaceous period (Aptian to Albian stages). This genus is known from articulated and somewhat complete specimens, from a locality known for the extraordinary preservation of the fossil remains found. "Tribodus" specimens have been preserved three-dimensionally, and acid-preparation methods have revealed much of the anatomy of this shark."Tribodus" is found to have dorsal fin-spines and head spines, though only in males.