Abstract

The early to middle Selandian fossiliferous Orp Sand Member of the Heers Formation in Belgium has regularly been excavated at its type-locality Maret for its rich and diversified selachian fauna. Among the abundant vertebrate remains, extremely rare mammal specimens have been found. Three isolated teeth have been published previously, all with uncertain affinities. The purpose ofthis study is to present new specimens from the same deposits, including a small well-preserved dentary of an adapisoriculid attributable to “Afrodon” germanicus, a fragmentary upper molar, referred to Berrulestes sp., and a premolar of a large arctocyonid. Among the previous specimens we identified Arctocyonides cf. weigelti. The adapisoriculid dentary offers new clues that allow transferring “Afrodon” germanicus to the genus Bustylus. The five mammal taxa from Maret indicate an age intermediate between reference-levels MP1-5 of Hainin, Belgium and MP6 of Cernay, France and present the greatest correlation with the rich Walbeck fauna in Germany. The deposits from Walbeck were usually thought to be slightly older than the late Thanetian deposits of Cernay. We infer here that the age of Walbeck is likely to be Selandian. The strong differences observed between Hainin on the one hand, and Walbeck and Cernay on the other hand, document a dispersal event from North America to Europe around the Danian-Selandian boundary.