A hyracoid from the Late Oligocene Red Sandstone Group of Tanzania, Rukwalorax jinokitana (gen. and sp. nov.)

[Extract] A striking array of fossil hyracoids has been described from northern Africa and the Arabian Peninsula, with several taxa recognized from Paleogene strata not only in the Fayum Depression of Egypt, but also in Morocco, Algeria, Tunisia, Libya and Oman (e.g., Sudre, 1979; Rasmussen, 1989 and references therein; Thomas et al., 1989; Gheerbrant et al., 2005). Hyracoids were abundant in these faunas, comprising up to 90% of the mammalian fauna recovered from the L-41 locality in the Jebel Qatrani Formation of Egypt (Rasmussen and Simons, 1991).\ud \ud Hyracoids appear to have achieved their apex in diversity during the Paleogene, at which time the group dominated the small-medium sized herbivorous niches in known faunas (Schwartz et al., 1995). During this time, they spanned a rabbit to rhinoceros range in body size, exhibiting a diversity of locomotor and dietary morphologies (Rasmussen et al., 1996). From the bunodont Geniohyus, to the common lophoselenodont Thyrohyrax, hyracoids flourished, assuming a vast array of niches that would later be occupied by immigrant artiodactyls and perissodactyls (Schwartz et al., 1995). Indeed, specializations for limb stabilization attributed to cursoriality in Antilohyrax pectidens suggest that in some ways it converged upon modern springboks in aspects of its locomotor habits (Rasmussen and Simons, 2000), whereas at the other extreme, postcranial specializations of the hind limb later emerged in some procaviids to permit extreme rotation for rock and tree climbing (Fischer, 1986)