Six rhinoceros not five. This is a brief report about new revision of white rhinocerus prepared by Colin P. Groves, Prithiviraj Fernando and Jan Robovský (PLoS ONE 5, 1-15, 2010). On re-assessing the taxonomy of the two forms of white rhinoceroses they find them to be morphologically and genetically distinct, warranting the recognition of the taxa formerly designated as subspecies: Ceratotherium simum simum the southern form and Ceratotherium simum cottoni the northern form, as two distinct species Ceratotherium simum and Ceratotherium cottoni respectively. The recognition of the northern form as a distinct species has profound implications for its conservation.