The dentition and relationships of Carpodaptes cygneus (Russell) (Carpolestidae, Plesiadapiformes, Mammalia), from the Late Paleocene of Alberta, Canada

Abstract

Re-examination of the dentitions of carpolestid plesiadapiform mammals from the late Paleocene Swan Hills locality, northern Alberta, and correlative localities in the vicinity of Roche Percée, southeastern Saskatchewan, Canada, indicates that Carpodaptes cygneus (Russell) as known from these sites is polyphyletic: the name C. cygneus is here restricted to the Swan Hills carpolestid, while the Roche Percée form represents a new, more derived species, Carpodaptes stonleyi. Other purported records of C. cygneus are reconsidered as well: C. cygneus from DW-1, central Alberta, is more appropriately dubbed C. cf. cygneus; C. cygneus at Canyon Ski Quarry, central Alberta, is best identified as C. cf. stonleyi, while C. cf. cygneus from Police Point, southeastern Alberta, has closest affinities to C. hazelae Simpson. Carpolestids from the Tongue River Formation, North Dakota, are referred to Carpodaptes cf. hobackensis Dorr and C. cf. hazelae. After a review of the available evidence, the recent hypothesis that C. cygneus and other North American carpolestids are congeneric with Carpocristes oriens Beard and Wang from the Paleocene or Eocene of China, is rejected.