Early and Middle Miocene Tragulidae of the Napak Region (Uganda) including the Oldest African tragulids: Taxonomic revision, stratigraphical background, and biochronological framework

Abstract

ABSTRACT Tragulids are ruminant artiodactyls living today in two distinct areas in Central Africa (Hyemoschus) and South plus South east Asia (Moschiola, Tragulus). Their fossil record, however, is distributed much more widely including Europe. Yet, their palaeobiogeography and phylogeography is not fully understood. Taxonomy in need of revision, limited data and biochronological controversies hamper the reconstruction of the irevolutionary history. This study provides a taxonomic revision of tragulid faunas from late Early Miocene to early Middle Miocene sites at Napak (Uganda), which include the oldest known record on the African continent. Morphological and metrical characters of dentition supports the presence of ?Siamotragulus songhorensis in Iriri Member (ca. 20.5 Ma), Napak Member (ca. 20.5–19 Ma), and Akisim Member (ca.16 Ma). ?Siamotragulus aff. songhorensis, ?Siamotragulus n. sp., and ?Afrotragulus sp. are documented sporadically in the Iriri and Napak Member. Dorcabune iririensis and Dorcabune chappuisi as well as Dorcatherium pigotti and Dorcatherium n. sp. are recorded in the Napak Member . The results confirm the previously described successive appearance with ?S. songhorensis followed by Dorcatherium (now Dorcatherium and Dorcabune). However, our data suggest a higher diversity than previously thought, and accordingly we provide a partially alternative interpretation of the evolutionary history of Miocene African tragulids.