Acrodus

Acrodus (from Greek: άκρος ákros, 'high' and Greek: ὀδούς odoús 'tooth') is an extinct genus of hybodont spanning from the Early Triassic to the Late Jurassic. (The Early Cretaceous species "Acrodus" nitidus affinity to the genus is questionable.) It was durophagous, with blunt, broad teeth designed for crushing and grinding. Some Middle Triassic species have been suggested to have grown to lengths of 1.8–2.5 metres (5.9–8.2 ft). Species are known from both marine and freshwater environments, with all Middle and Late Jurassic species only known from freshwater.