Abstract
Morotodon aenigmaticusgen. et sp. nov. (Mammalia, Metatheria, ?Herpetotheriidae) from the early or early-middle Miocene of equatorial Africa (Moroto II locality, Moroto District, northeastern Uganda) is characterized by a short anterior cingulum, a buccal shelf, a well-developed hypoconulid in a central position, and a trigonid and talonid with similar mesio-distal lengths. Its small size and morphology suggest mostly insectivorous-faunivorous feeding habits. The faunal association of Moroto II, as well as previous palaeoenvironmental analyses, suggest that Morotodon lived in open woodland and bushland areas surrounded by grasses. Morotodon aenigmaticus shows several features reminiscent of early herpetotheriids, such as Golerdelphys stocki (late Paleocene of North America), and Amphiperatherium ambiguum (Eocene of Europe); this suggests an origin for its lineage previous to the Oligocene. In summary, its affinities lie with Northern Hemisphere herpetotheriids, and, most probably, with European ones.