Paleocene emergence of elephant relatives and the rapid radiation of African ungulates

Emmanuel Gheerbrant (1)

1 CR2P - Centre de Recherche en Paléontologie - Paris

Elephants are the only living representatives of the Proboscidea, a formerly diverse mammalian order whose history began with the 55-million years (mys) old Phosphatherium. Reported here is the discovery from the early late Paleocene of Morocco, ca. 60 mys, of the oldest and most primitive elephant relative, Eritherium azzou-zorum n.g., n.sp., which is one of the earliest known representatives of modern placental orders. This well supported stem pro-boscidean is extraordinarily primitive and condylarth-like. It provides the first dental evidence of a resemblance between the proboscideans and African ungulates (paenungulates) on the one hand and the louisinines and early macroscelideans on the other. Eritherium illustrates the origin of the elephant order at a previously unknown primitive stage among paenungulates and ''ungu-lates.'' The primitive morphology of Eritherium suggests a recent and rapid paenungulate radiation after the Cretaceous-Tertiary boundary, probably favoured by early endemic African paleoeco-systems. At a broader scale, Eritherium provides a new old calibration point of the placental tree and supports an explosive placental radiation. The Ouled Abdoun basin, which yields the oldest known African placentals, is a key locality for elucidating phylogeny and early evolution of paenungulates and other related endemic African lineages. Africa-Morocco ͉ Afrotheria ͉ Paenungulata ͉ Placentalia ͉ Proboscidea

Domains: Paleontology; Populations and Evolution [q-bio.PE]; Systematics, Phylogenetics and taxonomy

Emmanuel Gheerbrant. Paleocene emergence of elephant relatives and the rapid radiation of African ungulates. Proceedings of the National Academy of Sciences of the United States of America, 2009, 106 (26), pp.10717-10721. ⟨10.1073/pnas.0900251106⟩. ⟨mnhn-02264831⟩