First occurrence ofXenopus(Anura: Pipidae) on the Arabian Peninsula: A new species from the Upper Oligocene of Yemen

Abstract

A freshwater interbed of the Yemen Volcanic Group in central western Yemen yielded impressions of numerous, articulated, mostly complete frog skeletons. Recent dating of the volcanics and the stratigraphic position of the fossil bearing bed in the sequence support a Late Oligocene age for the frogs. These frogs are described as a new species ofXenopus, a genus that is today mostly confined to subsaharan Africa, and they provide evidence of the former, wider distribution of this genus on the Afro-Arabian Plate. The new species,X. arabiensis, differs from otherXenopusin its long maxilla and maxillary tooth row. It resemblesX. muelleriin its dentate, azygous vomer and prominent, cone-shaped, distally-pointed prehallux, but differs fromX. muelleriin having an atlantal intercotylar notch and longer distal prehallux bone. Climatic changes during the Neogene probably led to the extinction ofXenopuson the Arabian Peninsula; however, the timing of this event is not certain.