Monk seal

Monk seals are earless seals of the tribe Monachini. They are the only earless seals found in tropical climates. There are three species of monk seal: the Mediterranean monk seal, Monachus monachus; the Hawaiian monk seal, Neomonachus schauinslandi; and the Caribbean monk seal, Neomonachus tropicalis, which went extinct in the 20th century. The two surviving species are now extremely rare and in imminent danger of extinction.

The three monk seal species were classified in the same genus, Monachus, until, in 2014, following comparison of the mitochondrial cytochrome b DNA sequence of all three species, biologists placed the Caribbean and Hawaiian species in a new genus, Neomonachus. Fossils of the Mediterranean and Caribbean species are known from the Pleistocene. The time of divergence between the Hawaiian and Caribbean species, 3.7 million years (Ma) ago, corresponds to the closing of the Central American Seaway by the formation of the Isthmus of Panama. The divergence between Mediterranean seals and the New World clade was dated to 6.3 Ma ago.