The thorny Issue of African Porcupines. A new mandible of Hystrix makapanensis from Olduvai Gorge (Tanzania) and rediagnosis of the species

Several porcupine taxa are reported from the middle Miocene to the early Holocene in the Old World. Among these, five species of the subfamily Hystricinae occurred in Africa approximately in the last 6 Ma: the extinct Hystrix makapanensis, Hystrix leakeyi, and Xenohystrix crassidens and the still living Hystrix africaeaustralis and Hystrix cristata. The large-sized H. makapanensis is reported from numerous sites in East and South Africa between the early Pliocene and Early Pleistocene. In this paper, we describe a new mandible of H. makapanensis from the world-renowned Tanzanian paleontological and archeological site of Olduvai Gorge (HWK West; lowermost Bed II; ca. 1.8–1.7 Ma). The discovery of the new mandible triggered a comprehensive review of the entire African record of H. makapanensis. In particular, we describe or re-analyze the samples from South Africa (Makapansgat Limeworks, Gondolin, Kromdraai, Swartkrans, and Sterkfontein), Tanzania (Olduvai and Laetoli), Ethiopia (Omo Shungura and Hadar), and Kenya (Chemeron), enriching the quantity of specimens confidently referable to this species and above all improving the information on its craniodental anatomy. On this basis, we: (1) propose an emended diagnosis of H. makapanensis; (2) point out the morphological and biometric differences between H. makapanensis and other African Hystricinae (also in terms of body mass); and (3) broaden the knowledge on the geographical and chronological distribution of this extinct species.