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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]

Premise: Nearly 200 araceous leaves and two spadices have been identified among Paleocene fossils from the Blindman River locality near Blackfalds, Alberta, Canada. Although not found in attachment, these probably represent parts of the same extinct plant species. Methods: Specimens were studied using light microscopy. Phylogenetic analyses using a morphological matrix of living and fossil Araceae were performed using TNT version 1.5 to help establish relationships of the fossil leaves and spadices within Araceae and to each other. Results: Leaves are simple with a broad petiole, entire margin, and elliptic to ovate or oblong blade with an acute to slightly rounded apex. A multi‐veined midrib extends into the basal region of the blade. Parallelodromous primary veins of two orders diverge at acute angles, converging with a submarginal vein or at the apex. Transverse veins are opposite percurrent, producing rectangular to polygonal areoles. Higher‐order veins are mixed opposite/alternate. Spadices are cylindrical, with helically arranged, bisexual, perigoniate flowers, each with six free tepals and a protruding style. Fruits are trilocular, with axile placentation and one seed per locule. Conclusions: Leaves are assignable to the fossil genus Orontiophyllum J. Kvaček & S.Y. Sm. as O. grandifolium comb. nov. Spadices are described as Bognerospadix speirsiae gen. et sp. nov. Leaves and spadices each conform to an early‐diverging lineage of Araceae, increasing the known diversity of Proto‐Araceae (viz., subfamilies Gymnostachydoideae and Orontioideae). Together, they provide strong evidence for extinct Proto‐Araceae with novel combinations of characters shortly after the Cretaceous‐Paleogene floral transition. [ABSTRACT FROM AUTHOR]

Although multituberculates are among the best-represented mammals of the Late Cretaceous and early Paleogene in North America, their evolution during the first several tens to hundreds of thousands of years following the Cretaceous–Paleogene (K–Pg) impact event is largely obscure. A better understanding of the early Paleogene record of multituberculates is crucial, for their dominance in early Paleocene mammalian faunas is unquestionably a result of rapid evolution during the immediate post-impact interval, and they accordingly played an important role in the evolution of mammalian communities more generally. I report on a new multituberculate from the early Paleocene of southwestern Alberta, in rocks of the Willow Creek Formation, the first such occurrence in this otherwise poorly known unit. The new multituberculate, Aenigmamys aries gen. et sp. nov., most closely resembles the ptilodontid Kimbetohia campi in comparable parts of the dentition and sheds light on the early evolution of Ptilodontidae, one of the major cimolodontan families that diversified during the Paleocene. The presence of Aenigmamys in mammalian faunas that lived soon after the K–Pg boundary implies a still-deeper evolutionary history for Ptilodontidae that may have extended into the Late Cretaceous. Aenigmamys is part of a new mammalian fauna from southwestern Alberta, the taxonomic composition of which includes a diversity of multituberculates, cimolestans, primates, and condylarths. The fauna correlates with those of middle Puercan age from other parts of the Western Interior of North America, and its high taxonomic diversity further corroborates previous hypotheses that multituberculate recovery — and mammalian recovery more generally — occurred relatively quickly after the K–Pg extinction event. [ABSTRACT FROM AUTHOR]

Albertosuchus knudsenii gen. et sp. nov. is described on the basis of an incomplete skeleton from the lower part (uppermost Cretaceous) of the Scollard Formation, southern Alberta, Canada. It is probably a crocodyloid, the only Canadian representative of the group and also the sole crocodylian known during the latest Cretaceous in Canada. Within the Crocodyloidea, A. knudsenii is one of the most basal forms and shares a sister-group relationship with the European genus Arenysuchus. However, it needs to be emphasized that because of its incompleteness, phylogenetic relationships proposed here for A. knudsenii may change when better-preserved specimens are found. Albertosuchus knudsenii differs from other crocodyloids in having no premaxilla-maxillary notch, a very short mandibular symphysis with the involvement of the splenial, and an extremely deep hypapophysis on the last cervical and anterior dorsal vertebrae. The discovery of A. knudsenii may expand the geographical range of the Crocodyloidea into Canada during the Cretaceous. Crocodylians in the lower part of the Scollard Formation are of low diversity compared with that of the corresponding Hell Creek Formation of Montana and Lance Formation of Wyoming, both farther to the south in the USA. [ABSTRACT FROM AUTHOR]

Turtle fossils of Paleocene age have been recovered from four formations in Alberta, Canada: the upper (Paleocene) part of the Scollard Formation, the upper (Paleocene) portion of the Willow Creek Formation, and the exclusively Paleocene Porcupine Hills and Paskapoo formations. At least three non-trionychid turtle taxa can be recognized. Definitely present are a generically indeterminate baenid, the macrobaenid Judithemys backmani, and the chelydrid Protochelydra zangerli. The carapace of a juvenile chelydrid could be either a juvenile of P. zangerli or a fourth, distinct taxon. The macrobaenid J. backmani and the chelydrid P. zangerli are the most abundant non-trionychid turtles from the Paleocene of Alberta. The turtles from the Paleocene of Alberta differ from those of comparable age in New Mexico, USA, and other more southern localities in the North American Western Interior in ( i) the presence of macrobaenids and chelydrids and ( ii) the absence of kinosternoids. These differences mirror those of the Late Cretaceous, suggesting that biogeographic patterns of non-trionychid turtle distributions that were established during the Late Cretaceous in the Western Interior continued well into the Paleocene. [ABSTRACT FROM AUTHOR]

In addition to having a rich assemblage of mammalian fossils, the Gao Mine locality in the Paskapoo Formation of south-central Alberta has yielded numerous plant specimens of late Paleocene (late Tiffanian or Ti5) age. The plant fossils are preserved in siltstones and fine-grained sandstones interpreted as overbank sediments that were deposited on an aggrading floodplain. The assemblage is dominated by the cupressaceous conifer Metasequoia foxii and the cercidiphyllaceous dicot Joffrea speirsiae, including their well-preserved seedlings. The flora also contains foliage of the ferns Onoclea and Speirseopteris and the woody dicots Palaeocarpinus, Aphananthe/ Celtis , Aesculus, Beringiaphyllum, ? Trochodendron, and Wardiaphyllum, as well as seedlings of unknown dicotyledonous angiosperms. Metasequoia foxii and Speirseopteris are unique to the floras of Gao Mine and the nearby Munce's Hill site (Tiffanian Ti4). The remainder of the taxa are common in late Paleocene floras of North Dakota, Montana, and Wyoming, all USA. The floras of the nearby Joffre Bridge Roadcut and Blindman River sites (both Tiffanian Ti3) are more diverse, but both of those sites encompass a wider range of depositional environments and may include higher percentages of allochthonous material. Most of the Gao Mine material is autochthonous. The seedlings were buried in place, along with the surrounding leaf litter, preserving a record of the local plant community. [ABSTRACT FROM AUTHOR]

Although mammals of Paleocene age are well known from Alberta, their record is largely restricted to one lithological unit, the Paskapoo Formation (a record that includes mammals from the Cochrane area erroneously attributed to the Porcupine Hills Formation). We report here the first occurrence of Paleocene mammals from the Porcupine Hills Formation at exposures near the western edge of the city of Calgary. The assemblage, termed the Bearspaw local fauna, documents a diversity of multituberculate and eutherian mammals, including new species of the pentacodontid Aphronorus bearspawensis sp. nov., the mixodectid Eudaemonema bohachae sp. nov., the hyopsodontid Promioclaenus thnetus sp. nov., and a new genus and species of multituberculate ( Alopocosmodon hadrus gen. et sp. nov.) tentatively referred to the Microcosmodontidae. The Bearspaw local fauna also details the first Canadian occurrences of several taxa, including Ptilodus wyomingensis, Aphronorus fraudator, Bryanictis microlestes, Elpidophorus minor, and possibly Goniacodon. Preliminary biostratigraphic analyses suggest that the Bearspaw local fauna is middle Torrejonian (To2) in age, correlating most closely with near-coeval Gidley Quarry of Montana and Rock Bench Quarry of Wyoming. In addition to improving the depauperate record of Torrejonian mammals in western Canada, the new fauna is important in documenting a mammal assemblage from a lithological unit that is thought to have been deposited in semi-arid conditions, rather than the wetter and more humid conditions of the Paskapoo Formation. Further, the Bearspaw localities, along with several other recently discovered localities in the Calgary and Cochrane areas, closely bracket the 27n-26r chron boundary and as such will be important in detailing the Torrejonian-Tiffanian transition in western Canada. [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)