Ceratotherium mauritanicum

Ceratotherium mauritanicum is a species of fossil African rhinoceros found in the Late Pliocene to early Late Pleistocene of Morocco, Tunisia, and Algeria. It is disputed as to whether remains from the Pliocene of East Africa belong to this species, and if so, whether C. mauritanicum is ancestral to the modern white rhinoceros (Ceratotherium simum). During the early Late Pleistocene, sometime between 120,000–57,000 years ago, it was replaced in North Africa by the modern white rhinoceros.

Evolution
The phylogenetic position of C. mauritanicum is somewhat disputed. One model see it as to be located in a direct line of ancestry between the primitive Ceratotherium neumayri and the living white rhinoceros (Ceratotherium simum). Alternatively it was proposed to be the descendant of Ceratotherium efficax and an extinct sister taxon to C. simum. It retained primitive characters contemporaneously to the more progressive evolution of the genus Ceratotherium in eastern and southern Africa.

Fossils from the Pliocene of eastern Africa have also proposed to belong to this species. A 2011 study propoposed these remains to belong to a somewhat more primitive species, Ceratotherium efficax. A 2020 study considers C. efficax to be the same species as C. mauritanicum, however.

C. mauritanicum was widely distributed across northwestern Africa during the Quaternary, and often associated with archaeological sites. Petroglyphs in northern Africa occasionally depict rhinoceri but often are too schematic to allow a distinction of the figured species. Those showing characters typical of the white rhinoceros may in fact represent C. mauritanicum instead of C. simum, which may have been very similar in external appearance in life. Most characters used to distinguish C. mauritanicum from the modern C. simum are minor proportional differences, with the only easily discernable difference between the two species being the more robust limbs of C. simum, particularly the metapodial bones.

While its chronological range was historically uncertain, recent chonological work suggests that it was replaced in North Africa by the modern white rhinoceros during the early Late Pleistocene, sometime between 120,000–57,000 years ago, likely during a Green Sahara period.

Paleoecology
C. mauritanicum is supposed to have had an ecology very similar to the extant C. simum. It lived in open savannah landscapes with sufficient water and vegetation, a biome that has vanished from the Maghreb since the Early Holocene. Its food was probably dominated by grass.