Phylogeny and systematics of the Orycteropodidae (Mammalia, Tubulidentata)

Abstract

The systematics of the order Tubulidentata is poorly known. Its phylogeny has never been thoroughly analysed and only a single review has ever been performed, which was over 30 years ago. This situation has hampered palaeoecological and palaeobiogeographical studies of these Neogene mammals. The present revision of the Orycteropodidae deals with the phylogeny and systematics of all African and Eurasian species over the last 20 Myr. The first comprehensive cladistic analysis of the family is presented here. The results of this analysis, based on 39 coded morphological characters, supplemented by non-coded features taken from all over the skeleton, was used to reconstruct the phylogeny of the order Tubulidentata. Two distinct lineages within the genus Orycteropus are recognized and characterized. The new genus Amphiorycteropus is subsequently created, in order to harmonize taxonomy and phylogeny. The fossil genera Leptorycteropus and Myorycteropus are validated, bringing the number of genera in the order Tubulidentata to four. Moreover, within the family Orycteropodidae, the number of confirmed species is now 14. The outcome of this study allows us to propose a consistent palaeobiogeographical scenario for aardvarks. Finally, this revision represents the most comprehensive work on the evolutionary history of the order Tubulidentata to date, and provides a new framework for future studies.

Afrotherian affinities for endemic South American “ungulates”

“…The Tubulidentata does not erupt a functional, deciduous dentition, and the ontogeny of this clade is still poorly known Lehmann, 2009). In this way, and in contrast with most mammals, adult size among afrotherians is frequently reached prior to the eruption of many permanent teeth.…”

Variability in the Middle Stone Age of Eastern Africa

“…Fossil fauna from MSA sites include a number of specialized grazers that became extinct by the Holocene, implying important differences in animal communities and grassland composition (Faith et al 2011Marean 1992Marean , 1997. Five extinct mammals are reported from MSA sites, including an aardvark, Orycteropus crassidens (Lehmann 2009;MacInnes 1956), and four bovids characterized by extreme hypsodonty and/or body mass: a relative of the wildebeest, Rusingoryx atopocranion (Faith et al 2011;Pickford and Thomas 1984); the giant wildebeest Megalotragus sp. (Kelly 1996;Tryon et al 2012); an extinct blesbok, Damaliscus hypsodon Marean and Gifford-Gonzalez 1991); and the giant longhorn buffalo Syncerus antiquus (Marean 1992;Tryon et al 2012).…”

The new framework for understanding placental mammal evolution

“…(58) The quality of the fossil record of some afrotherian lineages, such as proboscideans, hyracoids and sirenians, is relatively good, (48,(59)(60)(61) and while that of other afrotherians is much poorer, it too is benefitting from a steady pace of discovery. (62)(63)(64)(65) Character evolution in southern placentals…”