Prehistoric Shark teeth, Otodus
Otodus is an extinct, cosmopolitan genus of mackerel shark which lived from the Paleocene to the Pliocene epoch. The name Otodus comes from Ancient Greek ὠτ (ōt, meaning “ear”) and ὀδούς (odoús, meaning “tooth”) – thus, “ear-shaped tooth”.
The fossils of Otodus indicate that it was a very large macro-predatory shark. The largest known teeth of O. obliquus measure about 104 millimetres (4.1 in) in height. The vertebral centrum of this species are over 12.7 cm (5 inch) wide. Scientists suggest that O. obliquus would have measured about 8–9 metres (26–30 ft) long. Other species were much larger, with O. auriculatus, O. angustidens and O. chubutensis being estimated to have reached maximum body lengths of 9.5 metres (31 ft), 11–12 metres (36–39 ft) and 13.5 metres (44 ft), respectively. The largest species, O. megalodon, was estimated to have reached a maximum body length of approximately 20 metres (66 ft).