Systematics and biogeography of eastern Caribbean frogs

This study examines the systematics and biogeography of frogs in the Eastern Caribbean, a biogeographical province consisting of the Lesser Antilles, Trinidad, and Tobago. A comprehensive collection of specimens was subjected to an analysis incorporating morphometric, osteological, and biochemical approaches. An investigation of $ alpha$-level taxonomy revealed the presence of four additional taxa: Colostethus chalcopis sp. nov. on Martinique, Eleutherodactylus amplinympha sp. nov. on Dominica, E. euphronides comb. nov. on Grenada, and E. shrevei comb. nov. on St. Vincent. Based on species distributions and detailed analyses of the largely congruent data sets, Eastern Caribbean frogs can be grouped into two major categories, those originating with South American stock and those of Greater Antillean ancestry. A South American origin is obvious for species which have no congeneric relatives in the Greater Antilles, e.g. C. chalcopis, Leptodactylus fallax, L. wagneri. Among the Eleutherodactylus species, northern Eastern Caribbean taxa form a monophyletic group within the E. auriculatus species group; the topology of relationships is ((E. barlagnei, E. pinchoni) ((E. amplinympha, E. martinicensis) E. johnstonei)). The southern Eastern Caribbean species may or may not form a monophyletic group, but E. euphronides and E. shrevei are sister taxa. The topology for these species is (E. urichi (E. terraebolivaris (E. euphronides, E. shrevei))). Thus, the Eastern Caribbean forms a biogeographic link between the large South American and Greater Antillean radiations of Eleutherodactylus; Eleutherodactylus is the only truly circum-Caribbean frog genus. Furthermore, historical evidence shows that the patchy, Caribbean-wide distribution of E. johnstonei is the direct result of accidental introduction mitigated by humans during the past three centuries