The Late Miocene Large Mammal Fauna from the Namurungule Formation, Samburu Hills, Northern Kenya

Abstract

By the Japan-Kenya Expedition, more than 1145 late Miocene vertebrate fossils were collected from the Namurungule Formation in Samburu Hills, Northern Kenya in 1982. These fossils are assigned to at least 29 taxa of which 21 are mammals, including Hominoid, Tetralophodon, two kinds of Hipparion, Brachypotherium, Kenyapotamus, and Pachytragus. Quantitatively, the taxa of Hipparion are the most predominant. But gomphothere, bovid, rhinocerotid and giraffid fossils are approximately as common as each other at Namurungule. Suids, hippopotamids and carnivores seem to be uniformly rare as fossils at Samburu. In this paper, 19 taxa of mammals are described and discussed briefly. The Namurungule mammalian fauna is closer in age to Ngorora (c. 11 m.y.) than to Mpesida (7 m.y.) from Kenya, and this fauna is similar to the faunas of Samos and Pikermi (Vallesian). It seems that the abundance of Hipparion, giraffids, rhinocerotids and bovids suggests a woodland to savannah environment at or near Namurungule during the upper Miocene. We find very little evidence to suggest that there was forest in the vicinity at the time of deposition.