Megalodon (Otodus megalodon), meaning "big tooth", is an extinct species of shark that lived approximately 23 to 3.6 million years ago (mya), during the Early Miocene to the Pliocene. It was formerly thought to be a member of the family Lamnidae and a close relative of the great white shark (Carcharodon carcharias). However, it is now classified into the extinct family Otodontidae, which diverged from the great white shark during the Early Cretaceous. Its genus placement is still debated, authors placing it in either Carcharocles, Megaselachus, Otodus, or Procarcharodon. This is because transitional fossils have been found showing that megalodon is the final chronospecies of a lineage of giant sharks originally of the genus Otodus which evolved during the Paleocene.