O rinoceronte branco é probablemente descendente do ''[[Ceratotherium praecox]]'' que viviu hai 7 millóns de anos. Restos deste rinoceronte foron atopados en [[Langebaanweg]], preto de [[Cidade do Cabo - Cape Town|Cidade do Cabo]].<ref name="Skinner">The Mammals of the Southern African Subregion, J.D. Skinner and RHN Smithers. 1990. 567</ref> Porén, unha revisión dos restos [[fósil]]es dos rinocerontes de África por Denis Geraads suxire que a especie de Langebaanweg é do xénero ''Ceratotherium'', pero non ''Ceratotherium praecox'' como o exemplar tipo de ''Ceratotherium praecox'' debe ser, de feitosenón '' [[Diceros praecox]]'', xa que amosa afinidades estreitas co rinoceronte negro'' [[Diceros bicornis]]''.<ref name="ReferenceA">PLIOCENE RHINOCEROTIDAE (MAMMALIA) FROM HADAR AND DIKKA (LOWER AWASH, ETHIOPIA), AND REVISION OF THE ORIGIN OF MODERN AFRICAN RHINOS, Denis Geraads, 2005</ref> It has been suggested that the modern white rhino has a longer skull than ''Ceratotherium praecox'' to facilitate consumption of shorter grasses which resulted from the long term trend to drier conditions in Africa.<ref name="Turner">Evolving Eden: An Illustrated Guide to the Evolution of the African Large-Mammal Fauna, Alan Turner and Mauricio Anton. Columbia University Press (2004) ISBN 0-231-11944-5, p. 224</ref> However, if ''Ceratotherium praecox'' is in fact ''Diceros praecox'', then the shorter skull could indicate a browsing species. Teeth of fossils assigned to ''Ceratotherium'' found at [[Makapansgat]] in South Africa were analysed for [[Isotopes of carbon|carbon isotopes]] and the researchers concluded that these animals consumed more than 30% browse in their diet, suggesting that these are not the fossils of the extant ''Ceratotherium simum'' which only eats grass.<ref name="Sponheimer">M. Sponheimer, K. Reed and J.A. Lee-Thorp [http://www.colorado.edu/anthropology/faculty/sponheimer/pdfs/Sponheimeretal01.pdf Isotopic palaeoecology of Makapansgat Limeworks Perissodactyla] South African Journal of Science Vol. 97 July/August 2001 pp. 327–328</ref> It is suggested that the real lineage of the white rhino should be; ''[[Ceratotherium neumayri]]'' → ''[[Ceratotherium mauritanicum]]'' → ''C. simum'' with the Langebaanweg rhinos being ''[[Ceratotherium sp.]]'' (as yet unnamed), with black rhinos being descended from ''C. neumayri'' via ''Diceros praecox''.<ref name="ReferenceA"/> It is likely then that the ancestor of both the Black and the White rhinos was a mixed feeder, with the two lineages then specialising in browse and graze, respectively.
