St. Mary River Formation

Last updated
St. Mary River Formation
Stratigraphic range: 71.9–67  Ma
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
↓
St Mary River Fm Strata.jpg
Strata of the St. Mary River Formation at the St. Mary Reservoir spillway.
Type Geological formation
Underlies Willow Creek Formation
Overlies Bearpaw Formation
Thicknessup to 762 metres (2,500 ft)
Lithology
Primary Sandstone, shale [1]
Other Mudstone, coal
Location
Coordinates 49°36′N114°06′W / 49.6°N 114.1°W / 49.6; -114.1
Approximate paleocoordinates 49°36′N86°30′W / 49.6°N 86.5°W / 49.6; -86.5
RegionFlag of Alberta.svg  Alberta,
Flag of Montana.svg  Montana
CountryFlag of Canada (Pantone).svg  Canada,
Flag of the United States.svg  USA
Type section
Named for St. Mary River
Named by George Mercer Dawson [2]
Year defined1883
Canada relief map 2.svg
Lightgreen pog.svg
St. Mary River Formation (Canada)
Canada Alberta relief location map - transverse mercator proj.svg
Lightgreen pog.svg
St. Mary River Formation (Alberta)

The St. Mary River Formation is a geologic formation of Late Cretaceous (71.9-67 Ma [3] ) age of the Western Canada Sedimentary Basin in southwestern Alberta and northwesternmost Montana. [4] [5] It was first described from outcrops along the St. Mary River by George Mercer Dawson in 1883, and it takes its name from the river.

Contents

Fossils from the formation include remains of dinosaurs, [6] as well as bivalve shells, plant fossils, and trace fossils. [7]

Lithology

The St. Mary River Formation is generally considered to consist of two units. The lower 30–60 meters (98–197 ft) of the formation was deposited in brackish water environments, and is characterized by fine-grained sandstones, grey shales, coquinoid beds, carbonaceous mudstones and coal beds. The remainder of the formation was deposited in freshwater fluvial and floodplain environments and is characterized by interbedded sandstone and siltstone, with minor occurrences of carbonaceous shale and coal.

Thickness and distribution

The St. Mary River Formation is part of an eastward-thinning wedge of sediments derived from the erosion of the mountains to the west. It is about 762 metres (2,500 ft) thick in the exposures along the Crowsnest and Castle Rivers, and about 457 metres (1,500 ft) thick along the Oldman River.

Relationship to other units

The St. Mary River Formation conformably overlies the Blood Reserve Sandstone, or the Bearpaw Formation where the Blood Reserve Sandstone is absent, and it is conformably overlain by the Willow Creek Formation. It extends from Glacier County, Montana to as far north as the Little Bow River in Alberta, where it grades into and intertongues with the contemporaneous strata of the Horseshoe Canyon Formation. [4] [5]

Fossil content

Flora

Eighteen species of plant leaves were described from the St. Mary River Formation in 1949. [8] More recent work downstream from the St. Mary Reservoir increased the total to at least 32 species. The assemblage includes remains of ferns, Ginkgo , conifers, [9] a Trapa -like plant, [10] and at least six types of large monocot leaves in addition to a sabaloid palm. [9]

Plants
GenusSpeciesPresenceMaterialNotesImages
Cardstonia C. tolmaniiNear Cardston, Alberta. [9] Belongs in Limnocharitaceae.
Hydropteris H. pinnata"Riverbank exposure on the north side of the St. Mary River approx. 50 m below the spillway of the St. Mary Reservoir, east of Cardston, Alberta." [11] Large segments of intact plants. [11] A hydropteridale fern.
Tolmania T. aquaticaNear Cardston, Alberta. [12] "Sixteen compression/ impression specimens". [12] A floating aquatic angiosperm.
Trapago T. angulataSouthern Alberta. [10] "Nearly 500 specimens of various isolated and attached organs". [10]
Zlatkovia Z. crenulataNear Cardston, Alberta. [13] "Sixty-seven coalified compression specimens of leaves, one attached to a stem". [13] An amphibious eudicot.

Molluscs

Beds of Ostrea and Corbicula shells are common in the basal, brackish water portion of the formation. The overlying freshwater beds include shells of freshwater and terrestrial molluscs. Shells of unionid freshwater mussels are common in the fluvial sandstones. [7]

Mammals

The mammals of the St. Mary River Formation were described by Sloan and Russell in 1974. [14]

Mammals
GenusSpeciesPresenceMaterialNotesImages
Cimolodon C. nitidusLocality 11, 15 miles north of Lundbreck, Alberta. [14] NMC 17667, a right M2. [14] A cimolodontid.
Cimolomys C. gracilisScabby Butte, Alberta. [14] "NMC 17662, 17663, 17664, 3 tooth fragments from at least 2 individuals." [14] A cimolomyid.
Ptilodus gracilis.jpg
Didelphodon?D.? sp.Scabby Butte, Alberta. [14] "ROM 7848, the badly worn trigonid of a right molar." [14]
Didelphodon NT small.jpg
Eodelphis?E.? sp.Scabby Butte, Alberta. [14] "ROM 7849, a worn, broken right molar". [14]
Leptalestes L. toevsiMontana. [15] A pediomyid.
Meniscoessus M. conquistaScabby Butte, Alberta. [14] "3 teeth from at least 2 individuals (ROM 7846, 7847, 7850)". [14] A cimolomyid.
Mesodma M. cf. thompsoniScabby Butte, Alberta. [14] NMC 17665. [14]
Miacidae?Genus and species undetermined.Scabby Butte, Alberta. [14] "NMC 9821, trigonid of a left lower molar". [14] Assignment to Miacidae is tentative until the complete tooth is known.
Nidimys N. occultusMontana. [15] A ptilodontoid.
Paracimexomys P. propriscusMontana. [15] A multituberculate.
Pediomys P. cf. cookiScabby Butte, Alberta. [14] NMC 21307, buccal portion of right upper molar. [14]
P. cf. krejciiScabby Butte, Alberta. [14] NMC 9820, right M1. [14]
Ptilodontoidea Genus and species indet.Montana. [15] MOR 2535. [15] A ptilodontoid comparable in size to the smallest Mesodma species. [15]
Turgidodon T. russelliMontana. [15] An alphadontid.

Dinosaurs

Dinosaur tracks

The St. Mary River Formation has produced relatively few dinosaur fossils from its outcrops in southwestern Alberta. [16] However, footprints and trackways have been found along the St. Mary and Oldman Rivers. More than 100 track-bearing stratigraphic units were documented in one section 177 metres (580 ft) thick, which is one of the highest densities of track-bearing layers reported from any succession. One footprint from the formation includes the first record of skin impressions from the bottom of a hadrosaur foot. [17]

Ornithischians

Ornithischians
GenusSpeciesLocationStratigraphic positionMaterialNotesImages

Anchiceratops [18]

A. ornatus [19]

Remains later found to be referrable to Anchiceratops, but it's not known what species. [18]

Montanoceratops Montanoceratops BW.jpg
Montanoceratops
Pachyrhinosaurus Pachyrhinosaurus.jpg
Pachyrhinosaurus

Edmontonia [20]

E. longiceps [20]

Montanoceratops [21]

M. cerorhynchus [21]

Pachyrhinosaurus [18]

P. canadensis [18]

Regaliceratops [22]

R. peterhewsi

  • Alberta

Theropods

Theropods
GenusSpeciesLocationStratigraphic positionMaterialNotesImages

Albertosaurus [18]

[18]

Saurornitholestes [23]

cf. Saurornitholestes sp. [23]

Troodon [24]

Troodon sp." [24]

Color key
Taxon Reclassified taxonTaxon falsely reported as presentDubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

See also

Related Research Articles

<i>Pachyrhinosaurus</i> Ceratopsid dinosaur genus from Late Cretaceous US and Canada

Pachyrhinosaurus is an extinct genus of centrosaurine ceratopsid dinosaur from the Late Cretaceous period of North America. The first examples were discovered by Charles M. Sternberg in Alberta, Canada, in 1946, and named in 1950. Over a dozen partial skulls and a large assortment of other fossils from various species have been found in Alberta and Alaska. A great number were not available for study until the 1980s, resulting in a relatively recent increase of interest in Pachyrhinosaurus.

<i>Montanoceratops</i> Extinct genus of dinosaurs

Montanoceratops is an extinct genus of small ceratopsian dinosaur that lived approximately 70 million years ago during the latter part of the Cretaceous Period in what is now Montana and Alberta. Montanoceratops was a small sized, moderately-built, ground-dwelling, quadrupedal herbivore, that could grow up to an estimated 2.5 m (8.2 ft) in length and 170 kg (370 lb) in body mass.

<span class="mw-page-title-main">Dinosaur Park Formation</span> Uppermost member of the Belly River Group geologic unit in Alberta, Canada

The Dinosaur Park Formation is the uppermost member of the Belly River Group, a major geologic unit in southern Alberta. It was deposited during the Campanian stage of the Late Cretaceous, between about 76.5 and 74.4 million years ago. It was deposited in alluvial and coastal plain environments, and it is bounded by the nonmarine Oldman Formation below it and the marine Bearpaw Formation above it.

The Oldman Formation is a stratigraphic unit of Late Cretaceous age that underlies much of southern Alberta, Canada. It consists primarily of sandstones that were deposited in fluvial channel and floodplain environments. It was named for exposures along the Oldman River between its confluence with the St. Mary River and the city of Lethbridge, and it is known primarily for its dinosaur remains and other fossils.

<span class="mw-page-title-main">Two Medicine Formation</span> Geological formation in Montana, United States and Alberta, Canada

The Two Medicine Formation is a geological formation, or rock body, in northwestern Montana and southern Alberta that was deposited between 83.5 ± 0.7 Ma and 70.6 ± 3.4 Ma, during Campanian time. It crops out to the east of the Rocky Mountain Overthrust Belt, and the western portion of this formation is folded and faulted while the eastern part, which thins out into the Sweetgrass Arch, is mostly undeformed plains. Below the formation are the nearshore deposits of the Virgelle Sandstone, and above it is the marine Bearpaw Shale. Throughout the Campanian, the Two Medicine Formation was deposited between the western shoreline of the Late Cretaceous Interior Seaway and the eastward advancing margin of the Cordilleran Overthrust Belt. The Two Medicine Formation is mostly sandstone, deposited by rivers and deltas.

<span class="mw-page-title-main">Judith River Formation</span> Fossil-bearing geologic formation in Montana, part of the Judith River Group

The Judith River Formation is a fossil-bearing geologic formation in Montana, and is part of the Judith River Group. It dates to the Late Cretaceous, between 79 and 75.3 million years ago, corresponding to the "Judithian" land vertebrate age. It was laid down during the same time period as portions of the Two Medicine Formation of Montana and the Oldman Formation of Alberta. It is an historically important formation, explored by early American paleontologists such as Edward Drinker Cope, who named several dinosaurs from scrappy remains found here on his 1876 expedition. Modern work has found nearly complete skeletons of the hadrosaurid Brachylophosaurus.

<span class="mw-page-title-main">Horseshoe Canyon Formation</span> Geological formation in Canada

The Horseshoe Canyon Formation is a stratigraphic unit of the Western Canada Sedimentary Basin in southwestern Alberta. It takes its name from Horseshoe Canyon, an area of badlands near Drumheller.

<span class="mw-page-title-main">Scollard Formation</span> Upper Cretaceous to lower Palaeocene stratigraphic unit of the Western Canada Sedimentary Basin

The Scollard Formation is an Upper Cretaceous to lower Palaeocene stratigraphic unit of the Western Canada Sedimentary Basin in southwestern Alberta. Its deposition spanned the time interval from latest Cretaceous to early Paleocene, and it includes sediments that were deposited before, during, and after the Cretaceous-Paleogene (K-Pg) extinction event. It is significant for its fossil record, and it includes the economically important coal deposits of the Ardley coal zone.

The Frenchman Formation is stratigraphic unit of Late Cretaceous age in the Western Canada Sedimentary Basin. It is present in southern Saskatchewan and the Cypress Hills of southeastern Alberta. The formation was defined by G.M. Furnival in 1942 from observations of outcrops along the Frenchman River, between Ravenscrag and Highway 37. It contains the youngest of dinosaur genera, much like the Hell Creek Formation in the United States.

<span class="mw-page-title-main">Cloverly Formation</span> Geological formation in the United States

The Cloverly Formation is a geological formation of Early and Late Cretaceous age that is present in parts of Montana, Wyoming, Colorado and Utah in the western United States. It was named for a post office on the eastern side of the Bighorn Basin in Wyoming by N.H. Darton in 1904. The sedimentary rocks of formation were deposited in floodplain environments and contain vertebrate fossils, including a diverse assemblage of dinosaur remains. In 1973, the Cloverly Formation Site was designated as a National Natural Landmark by the National Park Service.

<span class="mw-page-title-main">Bearpaw Formation</span> Geologic formation in North America

The Bearpaw Formation, also called the Bearpaw Shale, is a geologic formation of Late Cretaceous (Campanian) age. It outcrops in the U.S. state of Montana, as well as the Canadian provinces of Alberta and Saskatchewan, and was named for the Bear Paw Mountains in Montana. It includes a wide range of marine fossils, as well as the remains of a few dinosaurs. It is known for its fossil ammonites, some of which are mined in Alberta to produce the organic gemstone ammolite.

The Milk River Formation is a sandstone-dominated stratigraphic unit of the Western Canada Sedimentary Basin in southern Alberta, Canada. It was deposited in near-shore to coastal environments during Late Cretaceous time. Based on uranium-lead dating, palynology and stratigraphic relationships, deposition occurred between ~84.1 and 83.6 Ma.

The Belly River Group is a stratigraphical unit of Late Cretaceous age in the Western Canadian Sedimentary Basin.

<span class="mw-page-title-main">Foremost Formation</span> Geologic formation in Alberta, Canada

The Foremost Formation is a stratigraphic unit of Late Cretaceous (Campanian) age that underlies much of southern Alberta, Canada. It was named for outcrops in Chin Coulee near the town of Foremost and is known primarily for its dinosaur remains and other fossils.

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 lower Campanian through to the upper 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.

The Willow Creek Formation is a stratigraphic unit of Late Cretaceous to Early Paleocene age in the Western Canada Sedimentary Basin of southwestern Alberta. It was first described by George Mercer Dawson in 1883 along the Willow Creek, a tributary of the Oldman River. Williams and Dyer defined the type section in 1930 at the mouth of Willow Creek, east of Fort Macleod.

<span class="mw-page-title-main">Almond Formation</span> Geological formation in Wyoming, U.S.

The Almond Formation is a geological formation of Late Cretaceous age in Wyoming. It was deposited in marsh, deltaic, lagoonal, estuarine, and shallow marine environments along the western shore of the Western Interior Seaway. It consists primarily of fine- to medium-grained sandstone, siltstone, shale, and coal. Fossils from the Almond Formation include remains of dinosaurs and plants.

<span class="mw-page-title-main">Paskapoo Formation</span> Stratigraphic unit in Western Canada

The Paskapoo Formation is a stratigraphic unit of Middle to Late Paleocene age in the Western Canada Sedimentary Basin. The Paskapoo underlies much of southwestern Alberta, and takes the name from the Blindman River. It was first described from outcrops along that river, near its confluence with the Red Deer River north of the city of Red Deer, by Joseph Tyrrell in 1887. It is important for its freshwater aquifers, its coal resources, and its fossil record, as well as having been the source of sandstone for the construction of fire-resistant buildings in Calgary during the early 1900s.

This is an overview of the fossil flora and fauna of the Maastrichtian-Danian Hell Creek Formation.

<i>Regaliceratops</i> Extinct genus of dinosaurs

Regaliceratops is a monospecific genus of chasmosaurine ceratopsid dinosaur from Alberta, Canada that lived during the Late Cretaceous in what is now the St. Mary River Formation. The type and only species, Regaliceratops peterhewsi, is known only from an adult individual with a nearly complete skull lacking the lower jaw, which was nicknamed "Hellboy". Regaliceratops was named in 2015 by Caleb M. Brown and Donald M. Henderson. Regaliceratops has an estimated length of 5 metres (16 ft) and body mass of 2 metric tons. The skull of Regaliceratops displays features more similar to centrosaurines, which suggests convergent evolution in display morphology in ceratopsids.

References

  1. ↑ Lexicon of Canadian Geologic Units. "St. Mary River Formation" . Retrieved 2010-01-01.
  2. ↑ Dawson, G.M., 1883. Preliminary report on the geology of the Bow and Belly river region, Northwest Territory, with special reference to the coal deposits. Geological Survey of Canada, Report of Progress for 1880-81-82, Part B.
  3. ↑ Fowler, Denver Warwick (2017-11-22). "Revised geochronology, correlation, and dinosaur stratigraphic ranges of the Santonian-Maastrichtian (Late Cretaceous) formations of the Western Interior of North America". PLOS ONE. 12 (11): e0188426. Bibcode:2017PLoSO..1288426F. doi: 10.1371/journal.pone.0188426 . ISSN   1932-6203. PMC   5699823 . PMID   29166406.
  4. 1 2 Mossop, G.D. and Shetsen, I., (compilers), Canadian Society of Petroleum Geologists (1994). "The Geological Atlas of the Western Canada Sedimentary Basin, Chapter 24: Upper Cretaceous and Tertiary strata of the Western Canada Sedimentary Basin". Archived from the original on 2013-07-21. Retrieved 2013-08-01.{{cite web}}: CS1 maint: multiple names: authors list (link)
  5. 1 2 Prior, G. J., Hathaway, B., Glombick, P.M., Pana, D.I., Banks, C.J., Hay, D.C., Schneider, C.L., Grobe, M., Elgr, R., and Weiss, J.A. (2013). "Bedrock Geology of Alberta. Alberta Geological Survey, Map 600". Archived from the original on 2013-07-05. Retrieved 2013-08-13.{{cite web}}: CS1 maint: multiple names: authors list (link)
  6. ↑ 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. ISBN   0-520-24209-2.
  7. 1 2 Hamblin, A. P. (1998). "Edmonton Group/St Mary River Formation: Summary of Literature and Concepts. Geological Survey of Canada, Open File 3578" (PDF). Retrieved 2014-01-31.[ permanent dead link ]
  8. ↑ Bell, W.A. 1949. Uppermost Cretaceous and Paleocene floras of western Canada. Geological Survey of Canada, Bulletin 13, 231 p.
  9. 1 2 3 Riley, M.G. and Stockey, R.A.(2004). Cardstonia tolmanii gen. et sp. nov (Limnocharitaceae) from the Upper Cretaceous of Alberta, Canada. International Journal of Plant Sciences 165(5): 897-916.
  10. 1 2 3 Stockey, R.A. and Rothwell, G.W. (1997). The aquatic angiosperm Trapago angulata from the Upper Cretaceous (Maastrictian) St. Mary River Formation of southern Alberta. International Journal of Plant Sciences 158(1): 83-94,
  11. 1 2 Rothwell, G. W.; Stockey, R. A. (1994). "The Role of Hydropteris pinnata gen. et. sp. nov. In Reconstructing the cladistics of Heterosporous Ferns". ERA. doi:10.7939/R3QZ22T7R . Retrieved 2022-08-17.
  12. 1 2 Edmonds, Nathaniel L.; Stockey, Ruth A.; Rothwell, Gar W. (2022-08-04). "Late Cretaceous Aquatic Vegetation: Tolmania aquatica gen. et sp. nov., from Southern Alberta, Canada". International Journal of Plant Sciences. 183 (7): 567–575. doi:10.1086/721261. ISSN   1058-5893. S2CID   251354150.
  13. 1 2 Rothwell, Gar W.; Stockey, Ruth A. (2022-08-08). "Enriching our knowledge of Late Cretaceous wetland plant communities: Zlatkovia crenulata gen. et sp. nov., an amphibious angiosperm from the St. Mary River Formation, Alberta, Canada". Cretaceous Research. 140: 105328. Bibcode:2022CrRes.14005328R. doi: 10.1016/j.cretres.2022.105328 . ISSN   0195-6671. S2CID   251481599.
  14. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Sloan, R.E. and Russell, L.S. 1974. Mammals of the St. Mary River Formation (Cretaceous) of southwestern Alberta. Life Sciences Contributions, Royal Ontario Museum, Number 95.
  15. 1 2 3 4 5 6 7 Hunter, John P.; Heinrich, Ronald E.; Weishampel, David B. (2010-05-18). "Mammals from the St. Mary River Formation (Upper Cretaceous), Montana". Journal of Vertebrate Paleontology. 30 (3): 885–898. Bibcode:2010JVPal..30..885H. doi:10.1080/02724631003763490. ISSN   0272-4634. S2CID   128823128.
  16. ↑ Ryan, M. J., and Russell, A. P., 2001. Dinosaurs of Alberta (exclusive of Aves): In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, Introduction, page 281.
  17. ↑ Currie, P.J., Nadon, G.C. and Lockley, M.G. (1991). "Dinosaur footprints with skin impressions from the Cretaceous of Alberta and Colorado. Can. J. Earth Sci. 28: 102-115" (PDF). doi:10.1139/e91-009.{{cite journal}}: Cite journal requires |journal= (help)CS1 maint: multiple names: authors list (link)
  18. 1 2 3 4 5 6 7 8 9 10 11 12 "1.4 Alberta, Canada; 13. St. Mary River Formation," in Weishampel, et al. (2004). Pages 577-578.
  19. ↑ Listed as "? A. ornatus" in "1.4 Alberta, Canada; 13. St. Mary River Formation," in Weishampel, et al. (2004). Pages 577-578.
  20. 1 2 Listed as "Edmontonia cf. longiceps" in "1.4 Alberta, Canada; 13. St. Mary River Formation," in Weishampel, et al. (2004). Pages 577-578.
  21. 1 2 3 "3.11 Montana, United States; 11. St. Mary River Formation," in Weishampel, et al. (2004). Pages 583-584.
  22. ↑ Brown, Caleb M.; Henderson, Donald M. (June 4, 2015). "A new horned dinosaur reveals convergent evolution in cranial ornamentation in ceratopsidae". Current Biology (online). doi:10.1016/j.cub.2015.04.041.
  23. 1 2 Listed as "cf. Saurornitholestes sp." in "1.4 Alberta, Canada; 13. St. Mary River Formation," in Weishampel, et al. (2004). Pages 577-578.
  24. 1 2 Listed as "? Troodon sp." in "1.4 Alberta, Canada; 13. St. Mary River Formation," in Weishampel, et al. (2004). Pages 577-578.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.