Procerberus (Cimolestidae, Mammalia) from the Latest Cretaceous and Earliest Paleocene of the Northern Western Interior, USA

Abstract

Three species of the cimolestid Procerberus are currently recognized in the northern North\rAmerican Western Interior in latest Cretaceous and earliest Paleocene (Puercan North American\rLand Mammal Age) faunas: P. formicarum, P. andesiticus, and P. grandis. Analysis of a new\rtopotypic sample of P. formicarum from the Bug Creek Anthills locality provides an estimate of\rthe range of variation of its postcanine dentition. The three currently recognized species occur in\rPuercan 1 (Pu1) interval zone faunas, but two other occurrences indicate that the genus originated and initially diversified prior to the Cretaceous/Paleogene boundary. Rare occurrences at several localities and entries in faunal lists suggest even greater taxonomic diversity. Limited evidence suggests continued diversification in the later Puercan and possible survival of the genus into the Torrejonian. Procerberus grandis or a closely related species may be a sister group of primitive taeniodonts.