The megaloon (pronounced /ˡmɛ.gə.ləˌdɒn/ or MEG-a-la-don; meaning "big tooth" or in Greek as μέγας 'οδόντος) was a giant shark that lived in prehistoric times, between about 18 million to 1.5 million years agoa[›] and was the apex predator of its time. It is the largest carnivorous fish known to have existed, and quite possibly the largest shark to have ever lived. It is believed that the average size of the megalodon was between 12 metres (39 ft) and 18 metres (59 ft). This species is a member of the lamnidae family but its classification is in dispute and a new genus has been proposed. Fossil evidence has revealed that megalodon fed upon large animals, including the early whales.