Propalaeoryx Stromer 1926 (Ruminantia, Pecora, Giraffomorpha) revisited: systematics and phylogeny of an African palaeomerycoid
Résumé
We describe new mandibular and dental material of Propalaeoryx stromeri from
Langental (early Miocene, Sperrgebiet, Namibia), and re-describe the cranial anatomy of this
genus of African giraffomorphs. The occipital and nuchal anatomy of the two Propalaeoryx
species are described and emended differential diagnoses are presented. Several cranial and
postcranial characters are crucial for understanding the position of Propalaeoryx as a basal
member of the Palaeomerycoidea within the Giraffomorpha. We define the clade
Palaeomerycoidea as the least inclusive clade of giraffomorphs containing Triceromeryx and
Propalaeoryx. Finally, the phylogenetic position of Propalaeoryx unveils a putative early
African-Eurasian vicariance event among basal palaeomerycoids that probably took place
around the Oligo-Miocene boundary, a time when other ruminant lineages were also splitting.