Complete skull of Bothriogenys fraasi (Mammalia, Artiodactyla, Anthracotheriidae) from the Early Oligocene, Fayum, Egypt

Abstract

Bothriogenys is an endemic African anthracothere (Mammalia, Artiodactyla), which was first documented at the beginning of the last century by Schmidt in 1913. It is one of the most common genera and species that were unearthed from Early Oligocene deposits of North Africa, like those of the Fayum Depression, Egypt. It has been thought that the genus Bothriogenys probably give rise to the Early Miocene Brachyodus that dispersed to Europe and Asia around 20 million years ago. Here, we describe a complete skull of B. fraasi. The specimen is a nearly complete cranium with right canine, left and right upper first premolar‐upper third molar. The new skull has two mesial cristae on the upper premolars, three cristules on the metaconule and the upper fourth premolar has three roots. The main palatine foramina are located at the level of the mesial border of the upper fourth premolar and the internal choanae open well behind the upper molar. The cranial bones and the dentition indicate that Bothriogenys is located at the basal part of the subfamily Bothriodontinae and very close to early Miocene Brachyodus. If so Bothriogenys was likely among the first anthracotheriids to enter Africa. Continued anthracothere development and evolution ultimately gave rise to Early Miocene Brachyodus.