Megalodon (pron.: /ˈmɛɡələdɒn/ MEG-ə-lə-don; meaning "big tooth", from Greek μέγας (megas, "big") and ὀδον (odon, from ὀδούς, odous, "tooth")) is an extinct species of shark that lived approximately 28 to 1.5 million years ago, during the Cenozoic Era (late Oligocene to early Pleistocene).