DetailsAsteracanthus magnus tooth specimen of Bathonian age, that's approximately 166 to 168 Mya during the Jurassic period. These samples were collected from Stonesfield, Oxon, UK. Asteracanthus is an extinct genus of shark which arose in the Devonian and survived through to the Cretaceous. The teeth are approximately 3 cm in length and are sold individually in small plastic bags with an information label. *Note* these fossils were formerly known as Strophodus magnus.