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

A freshwater interbed of the Yemen Volcanic Group in central western Yemen yielded impressions of numerous, articulated, mostly complete frog skeleton s. Recent dating of the volcanics and the stratigraphic position of the fos sil bearing bed in the sequence support a Late Oligocene age for the frogs. These frogs are described as a new Species of Xenopus, a genus that is tod ay mostly confined to subsaharan Africa, and they provide evidence of the f ormer, wider distribution of this genus on the Afro-Arabian Plate. The new species, X. arabiensis, differs from other Xenopus in its long maxilla and maxillary tooth row. It resembles X. muelleri in its dentate, azygous vente r and prominent, cone-shaped, distally-pointed prehallux, but differs from X. muelleri in having an atlantal interecotylar notch and longer distal pre hallux bone. Climatic changes during the Neogene probably led to the extinc tion of Xenopus on the Arabian Peninsula;. however, the timing of this even t is not certain.