Distinction of Sivatherium from Libytherium and a new species of Libytherium (Giraffidae, Ruminantia, Mammalia) from the Siwaliks of Pakistan (Miocene)

This study deals with the issues around the synonymization of the large extinct giraffid genera Libytherium and Sivatherium. We performed a morphological and biometrical analysis of the cranial remains of these giraffid genera and resolved this question by formulating criteria to distinguish Libytherium from Sivatherium, and to justify their systematic position within the Giraffidae. The present study also reports a new species of the genus Libytherium, Libytherium proton nov. sp. from the Chinji Formation (late Middle Miocene) and the Dhok Pathan Formation (Late Miocene) of the Siwalik Group of the Indian subcontinent. This extends the biogeographic and biostratigraphic range of Libytherium because this taxon had never been reported from the Siwaliks, Asia and the Miocene before this study. This study also initiates a detailed reassessment of the African and Siwalik material currently attributed to genus Sivatherium (and some other genera) and their proper allocation within the Giraffidae.