Geological setting of vertebrate microfossil localities across the Cretaceous–Paleogene boundary in southwestern Saskatchewan, Canada

Abstract

The Frenchman and Ravenscrag formations of southwestern Saskatchewan, Canada, record an apparently continuous sequence of nonmarine clastic sediments across the Cretaceous–Paleogene (K–Pg) boundary. Extensive exposures of these fossil-rich sediments occur in the Frenchman River Valley, near the towns of Ravenscrag, Eastend, and Shaunavon, and have been a focus of study since the 1970s. Despite this long history of investigation, a comprehensive account of the geographic and stratigraphic positions of many of the significant fossil localities has yet to be published. Given this state of affairs, the goals of this paper are to (i) document the geographic locations, stratigraphic positions, and lithologies of 11 key vertebrate microfossil localities, including several new localities that have been recently discovered, and (ii) provide an update on the status of these fossil localities, the majority of which have not been sampled in the last 20 years. Four fossil localities are known from the lower Paleocene Ravenscrag Formation, all of which are Puercan in age: Rav W-1 (Pu2), French Fry (Pu1), Croc Pot (?Pu2), and Pine Cree (?Pu2). With the exception of Rav W-1, which has since been lost as a consequence of quarry reclamation, all of the Ravenscrag Formation localities remain accessible and continue to be productive. Seven vertebrate microfossil localities from the upper Maastrichtian Frenchman Formation are reported here, all of which are Lancian in age: Long Fall, Fr-1, By Gar Gap, Hairpin, Wounded Knee, Wounded C, and Gryde. With the exception of Long Fall and Wounded Knee, which have been lost through reclamation or construction, all of the Frenchman Formation localities are accessible and remain productive.

Early mammalian recovery after the end-Cretaceous mass extinction: A high-resolution view from McGuire Creek area, Montana, USA

“…We compiled genus-level presence/absence data for 16 faunas from Saskatchewan, Canada, to New Mexico, USA (Table 1). We excluded several faunas (e.g., Long Fall Horizon and Frenchman 1, Saskatchewan; Gas Tank Hill, Utah) that are poorly constrained temporally (Cifelli et al, 2004;Lofgren et al, 2004Lofgren et al, , 2005Redman et al, 2015;Clemens, 2017). When data sources listed a taxonomic occurrence modified with "cf."…”

A new, diminutive species ofCatopsalis(Mammalia, Multituberculata, Taeniolabidoidea) from the early Paleocene of southwestern Alberta, Canada

“…calgariensis , is larger than Taeniolabis lamberti Simmons, 1987, and exhibits significant overlap with T. taoensis in both size and cusp number (Middleton, 1982; Simmons, 1987). Catopsalis is first known from Late Cretaceous deposits in southwestern Saskatchewan, at the Medicine Hat Brick and Tile Quarry Long Fall horizon in the Frenchman Formation (Johnston and Fox, 1984; Fox, 1989), although the age of this locality has been challenged and debate continues (Fox, 1990, and see Lofgren et al, 2004; Redman et al, 2015). The earliest uncontested record of Catopsalis is from the earliest part of the Paleocene at several localities in the Western Interior of North America, during the Puercan North American Land Mammal Age (NALMA), where three relatively poorly represented species have been identified ( C .…”

A new species of the basal plesiadapiform Purgatorius (Mammalia, Primates) from the early Paleocene Ravenscrag Formation, Cypress Hills, southwest Saskatchewan, Canada: further taxonomic and dietary diversity in the earliest primates

“…Purgatorius coracis: Perhaps the most relevant comparison is between the dentitions of P. pinecreeensis and P. coracis (Fig. 3): both species are known from the Puercan of southwestern Saskatchewan (Pine Cree Park and Rav W-1, the type locality for P. coracis, are approximately 30 km from one another), although P. coracis is slightly older (Fox and Scott 2011;Redman et al 2015). As regards the upper dentition, UALVP 51003, a left P4 of P.…”

“…A large sample was obtained from the locality by the Royal Tyrrell Museum of Palaeontology in 2012, resulting in discovery of the specimens described here, as well as significant new mammal material, to be described elsewhere (Scott et al in prep.). The Pine Cree Park locality is provisionally considered middle Puercan (Pu2) based on the mammal assemblage and recently analyzed palynomorphs (Redman et al 2015).…”