monk seals are earless seals (true seals) of the tribe monachini. the tribe was first conceived by victor blanchard scheffer in his 1958 book "seals, sea lions, and walruses: a review of the pinnipedia". the two genera of monk seals, "monachus" and "neomonachus", comprise three species: the mediterranean monk seal ("monachus monachus"), the hawaiian monk seal ("neomonachus schauinslandi"), and the caribbean monk seal ("n. tropicalis"), which became extinct in the 20th century. all three monk seal species were classified in genus "monachus" until 2014, when comparison of the species' mitochondrial cytochrome b dna sequences led biologists to place the caribbean and hawaiian species in a new genus, "neomonachus".