Pelorovis
Pelorovis ("prodigious/monstrous sheep") is an extinct genus of African wild cattle which first appeared in the very beginning of the Pleistocene era 2.5 million years ago and became extinct at the end of the Late Pleistocene about 12,000 years ago or even during the Holocene some 4,000 years ago. Taxonomy. The genus was first described by Hans Reck in 1928 to house his new species "P. oldowayensis", which he described from bones originally found by him in Olduvai Gorge in northern German East Africa (Tanzania) in 1913, the first ever time this famous locality was explored by a  palaeontologist. The holotype is a fossil skull and assorted bones kept in Berlin. The species "P. kaisensis" was named in 1994 from Kaiso, Uganda. Hadjouis and Sahnouni considered it to be closer to "Syncerus" in 2005. Systematics. A 2007 study by Bienvenido Martínez-Navarro and colleagues of the morphology of the fossil remains came to the conclusion that "Pelorovis" is probably not monophyletic. These authors reclassify the early forms of the genus, "P. turkanensis" and "P. oldowayensis", in the genus "Bos". In contrast, they find that the late Pleistocene form "Pelorovis antiquus" seems to be a close relative of the  modern African buffalo ("Syncerus caffer"). This approach essentially subsumes the genus as a synonym of "Bos", because the type species is "P. oldowayensis". A number of the authors of this study reiterated their classification of the taxa "Pelorovis turkanensis" and "P. oldowayensis" in the genus "Bos" in another paper published 2014. Alexandre Hassanin follows the interpretations of Martínez-Navarro "et al"., pointing to previous genetics work which show that the bovid lineages which produced the modern species within the genera "Bos", "Bubalus" and "Syncerus" split from each other some eight to nine million years ago, indicating that either the fossil  ancestors of these species have not yet been discovered, or that they already have been found, but are taxonomically misidentified. He further points out that Martínez-Navarro "et al". are only looking for the ancestor of "Bos primigenius" in their studies of African fossil bovids, and that the Asian species of "Bos" may have been derived from other fossil species. Lastly, Hassanin notes that if "Pelorovis" is reduced into synonymy due to these studies, this also implies the other Pleistocene fossil genera "Leptobos" and "Epileptobos" are synonymous with "Bos". A 2018 study by Tong "et al". of the Chinese fossil  representation of "Bos primigenius" uses morphology to dispute these conclusions regarding these taxa belonging to the genus "Bos", as well as if they are the ancestral line from which "Bos" evolved, instead hewing to the traditional interpretation that the Indian Early Pleistocene fossil species "Bos acutifrons" is the primordial ancestor of "Bos". "Syncerus antiquus" was described by Georges Louis Duvernoy in 1851 from a skull discovered along the Bou Sellam River near the city of Sétif, Algeria. It was found at one meter in depth, when excavating the foundations of a new mill, and subsequently sent to Paris. Duvernoy believed  this species to be closely related to the Asian water buffalo "(Bubalus bubalis)" and classified it as "Bubalus antiquus". Several other fossils of "S. antiquus" were described under the names "Bubalus bainii" and "Bubalus nilssoni". In 1949, Dorothy Bate recognized that these buffaloes were conspecific and not related to "Bubalus". She placed these fossils in a new genus, "Homoioceras". However, the type species of "Homoiceros" was found to be synonymous with the Cape buffalo, invalidating the genus. It was subsequently moved to "Pelorovis" in 1978. However, a link with the living Cape buffalo has been noted based on morphological and  systematic grounds, and since 1994 it has been suggested that "P. antiquus" be moved into "Syncerus." This proposal has since gained widespread acceptance. Etymology. The etymology of the generic epithet ""pelorovis"", chosen by Reck in 1928, is compounded from the Greek πέλωρος ("péloros") in the sense of "monstrous" or "huge and terrible" and Latin "ovis", meaning "sheep". Description. "Pelorovis" resembled an African buffalo, although it was larger and possessed longer, curved horns. "Pelorovis" probably weighed about , with the largest males attaining . This ranks it as one of the largest bovines, and indeed one of the largest ruminants ever to have  lived, rivalling the extinct American long-horned bison ("Bison latifrons"), and the extinct Asiatic giraffid "Sivatherium giganteum", as well as the extant African giraffe ("Giraffa camelopardalis") in weight. The bony cores of the horns were each about long; when covered with keratin (which does not survive fossilisation) they could have been up to twice this length. The horns pointed away from the head, each forming a half circle in the species "Pelorovis oldowayensis" and "P. turkanensis". "P. oldowayensis" was broadly the same size as modern African buffalo, but its legs were longer, and the elongated head of this species was  reminiscent to those of the modern Alcelaphinae. Distribution. "P. oldowayensis" occurred in sub-Saharan Africa and disappeared 800,000 years ago. The best fossils of "P. oldowayensis" are known from the Olduvai Gorge in Tanzania.