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A large collection of dentigerous jaws quarried from the Gao Mine locality, late Paleocene, Paskapoo Formation, central Alberta, Canada, documents a new species of the early Paleogene phenacodontid "condylarth" Ectocion Cope, 1882. The new species, Ectocion stockeyae, the smallest of the genus, occurs well before the abrupt global warming at the Paleocene–Eocene Thermal Maximum, an event purportedly causing the rapid evolution of "dwarfed" mammals, including a species of Ectocion; however, there is no evidence of increased temperatures at Gao Mine to account for the small size of Ectocion stockeyae, raising questions of the relationship between temperature and body size in Ectocion. Ectocion stockeyae also exhibits sexual dimorphism of the canines, a pattern in mammals often associated with a population structure in which the males are relatively few and polygynous, resulting in intense male rivalry for mating success. The sample of Ectocion stockeyae from Gao Mine includes a substantial majority of "juvenile" individuals retaining deciduous posterior premolars, many even after eruption of the molars had been completed, suggesting short life spans, accelerated growth, and rapid dental development in this species as expressed in Schultz's Rule. [ABSTRACT FROM AUTHOR]

Plesiadapidae are a family of Paleogene mammals thought to have phylogenetic affinities with modern Primates. We describe previously unpublished dentitions and the first skull and isolated petrosals of the plesiadapid Pronothodectes gaoi, collected from middle Tiffanian localities of the Paskapoo Formation in Alberta. Other species of Pronothodectes, traditionally considered the most basal members of the Plesiadapidae, occur at earlier, Torrejonian horizons in Montana, Wyoming, and Alberta. Classification of P. gaoi as a species of Pronothodectes has proved controversial; accordingly, we use the newly available samples and the more extensively preserved specimens to re-evaluate the generic affinities of this species. Included in our study are comparisons with craniodental material known for other plesiadapids and plesiadapiforms. Cladistic analysis of craniodental characters is used to assess the hypothesis that P. gaoi and other species in this genus are basal members of the Plesiadapidae. The new dental evidence confirms that P. gaoi lacks derived character states of other plesiadapids except for a variably present fissuring of the m3 hypoconulid. Moreover, several aspects of the cranium seem to be more primitive in P. gaoi (i.e., more like nonplesiadapid plesiadapiforms) than in later occurring plesiadapids, such as Plesiadapis tricuspidens and Plesiadapis cookei. Cladistic analysis of craniodental morphology supports a basal position of P. gaoi among species of Plesiadapidae, with the exception of other species of Pronothodectes. The basicranium of P. gaoi preserves a laterally placed bony canal for the internal carotid neurovascular system, suggesting that this was the ancestral condition for the family. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

A primitive paromomyid plesiadapiform primate, Edworthia lerbekmoi new genus and species, is described from a recently discovered locality in the Paskapoo Formation, exposed at a road cut in Edworthy Municipal Park, Bow River Valley, Calgary, Alberta, Canada. The new taxon, probably middle Torrejonian (To2) in age, is based on two dentary fragments containing well-preserved dentitions that bracket p2-4, m1-3. With the exception of the basal Paromomys, E. lerbekmoi differs from all other paromomyids in retaining p2, but p2 in the new paromomyid is single-rooted, not two-rooted as in Paromomys. E. lerbekmoi differs further from Paroznoznys in having an enlarged anterior alveolus for a tooth immediately anterior to p2, hypothesized to be il. Unlike other paromomyids with an enlarged il, however, this tooth in E. lerbekmoi was obliquely, not horizontally, oriented and its alveolus opens dorsally, in the alveolar row, not anteriorly, as in other paromomyids in which il is greatly enlarged. This suggests that E. lerbekmoi represents a previously unknown paromomyid lineage that evolved from an ancestor having obliquely oriented lower incisors as in the basal primate Purgatorius, not from an ancestor in which il was already subhorizontal in orientation, as in Paromomys. If this working hypothesis is correct or whether in the future some other evolutionary scenario will better account for the unique anterior dentition in E. lerbekmoi, the new paromomyid nonetheless demonstrates that crucial aspects of the earliest history of the important plesiadapiform family Paromomyidae remain to be discovered. [ABSTRACT FROM AUTHOR]

Since 1908, the peculiar North American primate Picrodus Douglass, 1908 (Picrodontidae; Plesiadapiformes) has been thought to contain only a single species, P. silberlingi Douglass, 1908, of late Paleocene age. However, new collections from the Paskapoo Formation, Alberta, Canada, reveal that instead a rich complex of Picrodus species lived during the Paleocene. Three of these, Picrodus calgariensis, P. canpacius, and P. lepidus, are described herein as new. Others, represented by more fragmentary specimens from Canada and the United States, are included in this paper, but are not named. P. calgariensis, from Who Nose? (late Torrejonian), Calgary, is the most primitive known species of Pie rodus, having molars with little crenulation of the enamel. P. canpacius, from Cochrane 2 (earliest Tiffanian), northwest of Calgary, most resembles P. silberlingi sensu stricto, but differs in P4 structure, denser enamel crenulation, and weaker molar cusps. P. lepidus, from DW-2 (middle Tiffanian), near Red Deer, is the most advanced, having, for example, a two-rooted P4, tiny p3, and single-rooted p4. At least two of these species also occur in the United States, documented by fossils referred to P. silberlingi by previous workers. Dental evolution within Picrodus seems marked by several trends, including increase in size of i1, simplification of P4, reduction of molar cusps and crests, enlargement of the horizontal occlusal surfaces of the molars, and greater crenulation of enamel. From present knowledge, Zanycteris paleocenus Matthew, 1917 is dentally more primitive than Picrodus, Draconodus Tomida, 1982 is a valid genus, and picrodontids probably originated from ‘purgatoriid-grade’ plesiada-piforms in earliest Paleocene time. [ABSTRACT FROM AUTHOR]

Describes a new genus and species of palaeoryctids based on an incomplete maxilla containing well-preserved P3-4, M1-3, excavated from a late Paleocene horizon in the Paskapoo Formation in Alberta. Uncertainties about the relationships of palaeorctids to other mammals.

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-I, 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. [ABSTRACT FROM AUTHOR]

Abstract: A recent paper by Fanti and Miyashita (2009. A high latitude vertebrate fossil assemblage from the Late Cretaceous of west-central Alberta, Canada: Evidence for dinosaur nesting and vertebrate latitudinal gradient. Palaeogeography, Palaeoclimatology, Palaeoecology 275, 37–53) reports on a new assemblage of terrestrial vertebrate fossils from the Campanian (Late Cretaceous) of northern Alberta. In addition to the several dinosaur and microvertebrate specimens reported by Fanti and Miyashita (2009), the new assemblage also contains two mammalian teeth, identified by the authors as pertaining to “Cimolodon sp.” and “Didelphodon sp.” The taxonomic identifications of these teeth are either highly questionable or simply incorrect, and the accompanying descriptions are replete with errors; as a result of these lapses, at least part of the biogeographic conclusions drawn by the authors about the Kleskun Hills Park area is also rendered incorrect. While the discovery of a Late Cretaceous high-latitude vertebrate fauna in Alberta is unquestionably important, the significance of the Kleskun Hills mammalian taxa, both taxonomically and biogeographically, should be reconsidered. [Copyright &y& Elsevier]

Numerous non-mammalian vertebrates have evolved lethal venoms to aid either in securing prey or as protection from predators, but modern mammals that use venoms in these ways are rare, including only the duck-billed platypus (Ornithorhynchus), the Caribbean Solenodon, and a few shrews (Soricidae) (Order Insectivora). Here we report evidence of a venom delivery apparatus in extinct mammals, documented by well-preserved specimens recovered from late Palaeocene rocks in Alberta, Canada. Although classified within Eutheria, these mammals are phylogenetically remote from modern Insectivora and have evolved specialized teeth as salivary venom delivery systems (VDSs) that differ markedly from one another and from those of Solenodon and shrews. Our discoveries therefore show that mammals have been much more flexible in the evolution of VDSs than previously believed, contradicting currently held notions that modern insectivorans are representative of the supposedly limited role of salivary venoms in mammalian history. Evidently, small predatory eutherians have paralleled colubroid snakes in evolving salivary venoms and their delivery systems several times independently. [ABSTRACT FROM AUTHOR]

Paromomyidae are one of several families of plesiadapiforms that flourished during the Paleocene in North America soon after the extinction of non-avian dinosaurs some 66 million years ago. Although they are often among the best-represented plesiadapiforms in mammalian faunas in both North America and Europe, the early history of paromomyids is poorly understood, and their fossil record at higher latitudes is comparatively depauperate. We report here on the discovery of two new species of paromomyids from Paleocene deposits in southwestern Alberta: Edworthia greggi new species is the second known species of the basal paromomyid Edworthia Fox, Scott, and Rankin, 2010 whereas Ignacius glenbowensis new species is among the most abundantly represented species of Ignacius Matthew and Granger, 1921. These new discoveries document, for the first time, parts of the upper dentition of Edworthia, and the new species of Ignacius represents the first new, pre-Clarkforkian species of the genus to be described in nearly 100 years. A comprehensive phylogenetic analysis of nearly all known paromomyid taxa (including the new species described herein) recovered both species of Edworthia near the base of the paromomyid tree in a polytomy with Paromomys depressidens Gidley, 1923 and a paraphyletic Ignacius. The new paromomyids from Alberta not only increase the known taxonomic diversity of Edworthia and Ignacius but also add significantly to knowledge of the dental anatomy of these poorly known genera and further add to a uniquely Canadian complement of Paleocene plesiadapiforms. UUID: http://zoobank.org/a2f31cfe-09b9-4168-b09f-9d0c3d0af342 [ABSTRACT FROM AUTHOR]

A new eutherian mamma! of uncertain taxonomic position is described on the basis of well-preserved dental and gnathic specimens collected from localities in the Paleocene Paskapoo Formation of Alberta, Canada. Horolodectes sunae new genus and species is represented by seven incomplete maxillae, eleven incomplete dentaries, and numerous isolated teeth, together preserving nearly all of the postcanine dentition. The unusual dentition of Horolodectes n. gena. consists of trenchant, posteriorly leaning premolars in combination with comparatively primitive molars, suggestive of a masticatory cycle that consisted primarily of shearing and, to a lesser degree, horizontal grinding. Included among the specimens of Horolodectes is an incomplete dentary of an immature individual, with the teeth having been in various stages of eruption at the time of death. Although the dentition of Horolodectes broadly resembles that of apheliscine hyopsodontids, pentacodontine pantolestids, and "ungulatomorphs" among eutherian mammals, significant differences in the coronal structure of the teeth prevent unequivocal referral of Horolodectes to any of these groups, or to any known eutherian order. [ABSTRACT FROM AUTHOR]