Storrs L. Olson
Published: 1982
Total Pages: 76
Get eBook
The three papers in this volume summarize the previous literature on fossil vertebrates from the Bahamas, provide revisions of the previously described fossil specimens, include identifications of newly collected material, and discuss changes in the late Pleistocene environment of the Bahaman archipelago. Olson and Pregill review the history of fossil exploration in the Bahamas, describe the known fossil localities, and briefly discuss the depauperate mammalian fauna. Pregill reviews the Pleistocene herpetofauna of New Providence Island, which is similar to that found on the island today, the only extinct taxa being a tortoise (Geochelone), a crocodile (Crocodylus), an iguana (Cyclura), and a gecko of the genus Aristelliger (previously misidentified as Tarentola). Taphonomy of the New Providence deposits and the zoogeographical patterns of the herpetofauna are discussed in relation to arid climatic conditions of the Wisconsinan glacial period. It is suggested that the establishment of a north-south rainfall gradient within the Bahamas has caused more extinctions in the wetter northern islands, whereas a more diverse herpetofauna persists in the drier southern islands. Olson and Hilgartner review the fossil record of birds from the Bahamas and propose the following changes in nomenclature: Calohierax quadratus Buteo sp., Burhinus nanus Burhinus bistriatus nanus, Glaucidium dickinsoni Athene cunicularia, Otus providentiae Athene cunicularia, Bathoceleus hyphalus Melanerpes superciliaris, Corvus wetmorei Corvus nasicus. About 50% of the fossil avifauna of New Providence no longer occurs there and 40% is extinct in the Bahamas. Species composition indicates that the Bahamas in the late Pleistocene were drier and had more open savanna-like and broadleaf scrub habitats. Subsequent increases in rainfall caused habitat changes that resulted in extinction. The implications of this for modern ecological theories are discussed.