While regarded as one of the largest and most powerful predators to have ever lived, megalodon is only known from fragmentary remains, and its appearance and maximum size are uncertain. megalodon was formerly thought to be a member of the family Lamnidae and a close relative of the great white shark ( Carcharodon carcharias), but has been reclassified into the extinct family Otodontidae, which diverged from the great white shark during the Early Cretaceous. Otodus megalodon ( / ˈ m ɛ ɡ əl ə d ɒ n/ MEG-əl-ə-don meaning 'big tooth'), commonly known as megalodon, is an extinct species of giant mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Pliocene epochs.