The Wapiti Formation is a geological formation of the Western Canada Sedimentary Basin in northwestern Alberta, and northeastern British Columbia, Canada. Its deposition spanned the time interval from the upper Campanian through to the lower Maastrichtian, between approximately 80 and 68 Ma. It was named by G.M. Dawson in 1881, presumably for exposures along the lower part of the Wapiti River and downstream along the Smoky River in Alberta.Glass, D.J. (editor) 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba. Canadian Society of Petroleum Geologists, Calgary, 1423 p. on CD-ROM. .
Dinosaur remains are among the fossils that have been recovered from the Cretaceous portion of the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 574-588. . The Wapiti Formation does not produce many fossils due to its limited surface exposure and accessibility, although two Pachyrhinosaurus bone beds have been productive.Ryan, M. J., and A. P. Russell, 2001, Dinosaurs of Alberta (exclusive of Aves), in: Mesozoic Vertebrate Life, edited by Tanke, D. H., and K. Carpenter, Indiana University Press, pp. 279–297 Plant fossils and trace fossils have been unearthed here too.
Lithology The Wapiti Formation consists of interbedded sandstones, siltstones, shales and mudstones, with thin conglomerates, coal seams and bentonite beds. The sandstones are typically thick, pale grey, crossbedded and bentonitic. The middle part contains less sandstones, more mudstones, and fewer and thinner coals. The upper part contains thicker lenticular sandstones and more coals.
Depositional environment The Wapiti Formation was deposited in inland fluvial and floodplain environments, with local areas of lacustrine sediments. The sandstones were deposited mainly in fluvial channel environments, with siltstones, carbonaceous shales and coals accumulating in overbank settings.
Thickness and Distribution The Wapiti Formation rests conformably on the marine shales of the Smoky Group. It is more than thick in the foothills of the Canadian Rockies in the west, and it thins eastward to its erosional edge. It is correlative with the entire sequence of the Belly River Group, Bearpaw Formation, Edmonton Group and Scollard Formation in south-central Alberta. In most areas it is unconformably overlain by glacial and post-glacial sediments of Quaternary age, or exposed at surface. In a few upland areas it is unconformably overlain by Paleogene gravel deposits.
Vertebrate paleofauna
Indeterminate ankylosaurids, albertosaurines, pachycephalosaurids, ornithomimids, lambeosaurs, and saurolophines are known from Alberta. Corythosaurus is also known from the formation. Dinosaurs of the Wapiti Formation Genus Species Location Member Material Notes Imagescf. AlbertosaurusIndeterminate British Columbia TeethGorgosaurusG. libratus British ColumbiaApproximately near the top of Unit 2 or base of Unit 3 Natural mold of partial skullcf. GorgosaurusIndeterminate Alberta TeethBellatoripesB. fredlundi Alberta Unit 4Three trackways and an isolated print.Footprints of large tyrannosaurids.cf. Haenamichnuscf. H. isp. Alberta Unit 4An isolated track.Footprint of large azhdarchid pterosaur.BoreonykusB. certekorum Alberta Unit 3TroodonF. Fanti and T. 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(1-4):37-53Indeterminate Alberta Units 3 and 4N. J. Enriquez, N. E. Campione, C. Sullivan, M. Vavrek, R. L. Sissons, M. A. White and P. R. Bell. 2020. Probable deinonychosaur tracks from the Upper Cretaceous Wapiti Formation (upper Campanian) of Alberta, Canada. Geological Magazine (in press). doi:10.1017/S0016756820001247Teeth; probable troodontid footprints are also knownEdmontosaurus?E. sp. Alberta Unit 4Mummified specimen (UALVP 53722); originally referred to E. regalisHadrosauridae nov. tax.sp. nov. British Columbia A new taxon of hadrosaurid. PachyrhinosaurusCurrie, P.J., Langston, W., and Tanke, D.H. (2008). "A new species of Pachyrhinosaurus (Dinosauria, Ceratopsidae) from the Upper Cretaceous of Alberta, Canada." pp. 1-108. In: Currie, P.J., Langston, W., and Tanke, D.H. 2008. A New Horned Dinosaur from an Upper Cretaceous Bone Bed in Alberta. NRC Research Press, Ottawa, Ontario, Canada. 144 pp. P. lakustai AlbertaRichardoestesiaR. gilmorei AlbertaSaurornitholestesS. sp. Alberta
See also List of dinosaur-bearing stratigraphic units
References