The megamouth shark, Megachasma pelagios, is an extremely rare species of deepwater shark. Since its discovery in 1976, only a few megamouth sharks have been seen, with only 49 specimens known to have been caught or sighted as of 2011, including three recordings on film. Like the basking shark and whale shark, it is a filter feeder, and swims with its enormous mouth wide open, filtering water for plankton and jellyfish. It is distinctive for its large head with rubbery lips. It is so unlike any other type of shark that it is classified in its own family Megachasmidae, though it has been suggested that it may belong in the family Cetorhinidae of which the basking shark is currently the sole member.