Rails (Rallidae: Gallirallus) from prehistoric archaeological sites in Western Oceania

We evaluate the species-level systematics of 1336 bones of Gallirallus (Aves: Rallidae) from Pleistocene and Holocene archaeological sites in the Mariana Islands (Micronesia) and the Bismarck Archipelago and Solomon Islands (Melanesia) and describe four new species. In the Marianas, sites on Rota, Aguiguan, Tinian, and Saipan have yielded 15, 219, 1047, and 16 bones, respectively, that we refer to Gallirallus. We describe the bones from three islands as the new species G. temptatus (Rota), G. pisonii (Aguiguan), and G. pendiculentus (Tinian). Each species is presumed endemic to each island and probably evolved from colonizations by extant, volant G. philippensis. They vary in the reduction of pectoral and wing elements relative to leg elements, and thus in their degree of flightlessness. The limited material from Saipan we cannot distinguish reliably from that of G. philippensis, which is widespread in Melanesia and Polynesia but occurs today in Micronesia only on Palau. Twenty-one fragmentary bones of Gallirallus from four Pleistocene cave sites on New Ireland (Bismarcks) are described as a new, possibly flightless species, G. ernstmayri. One Pleistocene cave site on Buka (Solomons) revealed 18 specimens that we refer to Gallirallus woodfordi and G. rovianae, which occur today in the Solomons. These descriptions of rail bones from Western Oceania bring the total number of fossil (prehistorically extinct) Gallirallus species to eleven.