Cretoxyrhina

Cretoxyrhina.
Cretoxyrhina is an extinct genus of the order Lamniformes of mackerel sharks. Living in subtropical and temperate oceans worldwide about 107 to 73 million years ago, during the Late Cretaceous, Cretoxyrhina was one of the largest sharks of its time, 8 meters (26 ft) in length, and also among the fastest, with estimated burst speeds of up to 70 km/h (43 mph). It was an apex predator, preying on sharks and other large fish, mosasaurs, plesiosaurs, pterosaurs, and occasionally dinosaurs. Thanks to numerous discoveries of exceptionally well-preserved skeletons during the 19th and 20th centuries, the type species, C. mantelli, is one of the best-understood extinct sharks. These fossils show that it may have had a lifespan of up to forty years and a general build similar to the modern great white shark, but with facial and optical features similar to those of thresher sharks and crocodile sharks. Its ability to function in cold water was probably enhanced by regional endothermy.