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The fossil record of the earliest primates, purgatoriid plesiadapiforms, has become increasingly well documented during the past two decades, but their dietary preferences remain poorly understood. While the available evidence, which consists mostly of isolated teeth and incomplete jaws with teeth, suggests that purgatoriids were insectivorous to omnivorous, we describe here a new species of Purgatorius, Purgatorius pinecreeensis sp. nov., that extends the range of purgatoriid dental disparity toward greater omnivory than had been known before. Purgatorius pinecreeensis sp. nov., from the early Paleocene (Puercan) Ravenscrag Formation of southwestern Saskatchewan, differs from other species of Purgatorius in having slightly lower crowned teeth with a lower trigonid relative to talonid, blunter and more swollen major cusps, more transverse lower molar paracristids, and m3 with a more robustly developed posterior lobe. Taken together, these specializations enhanced the capacity for crushing and grinding at the expense of orthal shear, and represent the first instance of a modest degree of bunodonty in the family. The discovery of P. pinecreeensis sp. nov., along with other recently reported basal plesiadapiforms from the Puercan and Torrejonian of the northern Western Interior, lends additional support to the notion of a significant primate radiation soon after the Cretaceous-Paleogene extinction event. [ABSTRACT FROM AUTHOR]

The early Paleocene Purgatorius Van Valen and Sloan is the most primitive plesiadapiform primate yet discovered, mostly known from middle to late Puercan strata in Montana, deposited during the interval C29N of the geomagnetic polarity time scale. Here we describe Purgatorius coracis n. sp. from the Ravenscrag Formation, at the Ray W-l horizon, Medicine Hat Brick and Tile Quarry, southwestern Saskatchewan. This horizon occurs within C29R, making P. coracis the earliest known primate, while strengthening the evidence that plesiadapiforms, and hence primates, originated and underwent their initial evolutionary diversification in North America. Most North American mammalian local faunas correlating with C29R have been assigned to the Pul (earliest Pucrcan) interval zone, but the taxonomic composition of the mammals accompanying P. coracis at Ray W-l more resembles local faunas of Pu2 age. The occurrence at Ray W- I of Pu2 aspect mammals within C29R agrees with similar occurrences at the Hiatt and PITA Flats localities in Montana and North Dakota, also possibly correlated with C29R. The evidence from these three sites, all in the Williston Basin, suggests that in some areas of the Western Interior Pu2 aspect local faunas were coeval with those of latest Pul age, having evolved earlier than has commonly been assumed. [ABSTRACT FROM AUTHOR]

Abstract: An incomplete lower jaw with teeth documents the presence of a new genus and species of placental mammal from the Upper Cretaceous (Lancian; late Maastrichtian) Frenchman Formation, Saskatchewan, Canada. This new mammal is characterized by highly compressed lower molars that decrease in size from m1 to m3 and superficially resemble the molars of Tertiary Mesonychia. These resemblances, however, are interpreted as convergent, and the new mammal is classified in its own family and incertae sedis at the ordinal level. This new mammal thus joins other recent discoveries in western Canada of mammals of Tertiary aspect (Condylarthra; Taeniodonta) occurring in the Late Cretaceous. [Copyright &y& Elsevier]