Prolibytherium is an extinct genus of prolibytheriid artiodactyl ungulate native to Middle Miocene North Africa and Pakistan, from around 16.9 to 15.97 million years ago. Fossils of Prolibytherium were found in the Marada Formation of Libya, Vihowa Formation of Pakistan, and the Moghara Formation of Egypt.[1]
The long creature would have superficially resembled an okapi or a deer. Unlike these, however, Prolibytherium displayed dramatic sexual dimorphism, in that the male had a set of large, leaf-shaped ossicones with a width of, while the female had a set of slender, horn-like ossicones.[2]
The taxonomic status of Prolibytherium remains in flux. At one time, it was described as a relative of Sivatherium (as a precursor to "Libytherium maurusium" (S. maurusium)). Later, it would be regarded as a palaeomerycid, or either as a climacoceratid, or as a basal member of Giraffoidea. With the discovery and study of a female skull in 2010, Prolibytherium is tentatively confirmed as a climacoceratid. A recent study published in 2022 found it to be part of a separate family, Prolibytheriidae.[3]