Cosmopolitodus

Cosmopolitodus is an extinct genus of mackerel shark that lived between thirty and one million years ago during the late Oligocene to the Early Pleistocene epochs. Its type species is Cosmopolitodus hastalis. In 2021, Isurus planus was reassigned to the genus, and thus became the second species C. planus. However, some researchers still consider both species of Cosmopolitodus as species of Carcharodon. A possible third species, C. xiphodon was proposed, though it is now placed as junior synonym of Carcharodon plicatilis.

Its teeth can reach lengths up to 3.5 in (7.5 cm) and are found worldwide. It is believed to be an ancestor to the modern day great white shark, an argument supported by the transitional species Carcharodon hubbelli, but as of 2021, no phylogenetic analyses have been done for proof.