Phylogenetic analytical data, measurement analytical code to help identify dental fossils of Oligocene hyracoids from eastern Africa

The Topernawi area of west Turkana, northern Kenya, preserves a number of
recently discovered vertebrate fossil localities of mid-Oligocene age. The
Topernawi fauna provides important new data on mammalian evolution in
equatorial eastern Africa during the mid-Cenozoic. Here, we describe five
new species of hyracoids from Topernawi: Nengohyrax josephi, Abdahyrax
philipi, Geniohyus ewoii, Thyrohyrax lokutani, and Thyrohyrax ekaii. These
species range in reconstructed body mass from ∼8 to ∼150 kg, comparable to
the body size range that has been observed at other hyracoid-rich
Paleogene sites. We use Bayesian tip-dating phylogenetic analyses to
estimate hyracoid relationships. We find that non-Thyrohyrax species from
Topernawi are members of Geniohyidae, a clade of bunodont, Paleogene
hyracoids. Despite being approximately the same age as some of the
youngest and best-sampled horizons in the Jebel Qatrani Formation (Fayum,
northern Egypt), the Topernawi hyracoid fauna is distinct, and shows no
overlap at the species level; it also shows no species overlap with the
∼1.5–2.5 Ma younger Chilga localities in northern Ethiopia. The hyracoid
assemblage from Topernawi adds to a growing body of evidence which
suggests that certain distinctive clades known from earlier Oligocene
horizons in northern Africa (Saghatherium, Selenohyrax, Titanohyrax) did
not persist into the late Oligocene.