title: Biogeography and taxonomy of extinct and endangered monk seals illuminated by ancient DNA and skull morphology.
abstract: Extinctions and declines of large marine vertebrates have major ecological impacts and are of critical concern in marine environments. The Caribbean monk seal, Monachus tropicalis, last definitively reported in 1952, was one of the few marine mammal species to become extinct in historical times. Despite its importance for understanding the evolutionary biogeography of southern phocids, the relationships of M. tropicalis to the two living species of critically endangered monk seals have not been resolved. In this study we present the first molecular data for M. tropicalis, derived from museum skins. Phylogenetic analysis of cytochrome b sequences indicates that M. tropicalis was more closely related to the Hawaiian rather than the Mediterranean monk seal. Divergence time estimation implicates the formation of the Panamanian Isthmus in the speciation of Caribbean and Hawaiian monk seals. Molecular, morphological and temporal divergence between the Mediterranean and "New World monk seals" (Hawaiian and Caribbean) is profound, equivalent to or greater than between sister genera of phocids. As a result, we classify the Caribbean and Hawaiian monk seals together in a newly erected genus, Neomonachus. The two genera of extant monk seals (Monachus and Neomonachus) represent old evolutionary lineages each represented by a single critically endangered species, both warranting continuing and concerted conservation attention and investment if they are to avoid the fate of their Caribbean relative.
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany.
authors.forename: Dirk-Martin
authors.initials: DM
authors.lastname: Scheel
authors.affiliation: Division of Mammals, Smithsonian Institution, National Museum of Natural History, 10th Street and Constitution Ave, NW, Washington, DC 20560-0108, USA ; Department of Paleobiology, Smithsonian Institution, National Museum of Natural History, 10th Street and Constitution Ave, NW, Washington, DC 20560-0108, USA.
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Slater
authors.affiliation: Department of Biological Sciences, Fordham University, 441 East Fordham Road, Bronx, NY 10458, USA.
authors.forename: Sergios-Orestis
authors.initials: SO
authors.lastname: Kolokotronis
authors.affiliation: Division of Mammals, Smithsonian Institution, National Museum of Natural History, 10th Street and Constitution Ave, NW, Washington, DC 20560-0108, USA.
authors.forename: Charles W
authors.initials: CW
authors.lastname: Potter
authors.affiliation: Marine Mammal Pathology Services, 19117 Bloomfield Road, Olney, MD 20832, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: Rotstein
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany.
authors.forename: Kyriakos
authors.initials: K
authors.lastname: Tsangaras
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany.
authors.forename: Alex D
authors.initials: AD
authors.lastname: Greenwood
authors.affiliation: Division of Mammals, Smithsonian Institution, National Museum of Natural History, 10th Street and Constitution Ave, NW, Washington, DC 20560-0108, USA.
authors.forename: Kristofer M
authors.initials: KM
authors.lastname: Helgen
keywords: Ancient DNA; Panamanian Seaway; Phocidae; extinction; mitochondrial DNA; systematics