Almond Formation

Almond Formation
Stratigraphic range: CampanianMaastrichtian
73.6–71.1 Ma
TypeGeological formation
UnderliesLewis Shale
OverliesEricson Formation
Lithology
PrimarySandstone
OtherSiltstone, shale, coalb
Location
Coordinates41°36′25″N 109°13′34″W / 41.60694°N 109.22611°W / 41.60694; -109.22611
RegionWyoming
CountryUnited States

Southwestern Wyoming, incl. Almond formation

The Almond Formation is a geological formation of Late Cretaceous (Late Campanian-Early Maastrichtian[1]) 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.[2] Fossils from the Almond Formation include remains of dinosaurs[3] and plants.[4]

Vertebrate paleofauna

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Dinosaurs

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Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Dinosaurs of the Almond Formation
Genus Species Location Stratigraphic position Material Notes Images

Anchiceratops

Indeterminate

Represents a new genus and species of unnamed ceratopsid

Dromaeosaurus
Edmontonia
Edmontosaurus
Thescelosaurus
Unnamed chasmosaurine ceratopsid

Dromaeosaurus[5]

Indeterminate[5]

Edmontonia[5]

Indeterminate[5]

Edmontosaurus[5]

Indeterminate[5]

Maiasaura[5]

Indeterminate[5]

Paronychodon[5]

P. lacustris[5]

Saurolophus[6] S. sp. One specimen (AMNH 3651) consisting of partial cranial and postcranial remains, as well as skin impressions

Thescelosaurus[7]

Indeterminate[7]

Unnamed chasmosaurine ceratopsid[8]

Unnamed

Misidentified as Anchiceratops, it is actually a new species of Pentaceratops-like form that is the sister taxon to Bisticeratops.[9] Holotype was discovered in 1937.

Other vertebrates

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Non-dinosaur vertebrates found in the Almond Formation include crocodyliforms (indet.), turtles (Adocus cf. and Basilemys cf.), and ray-finned fish (Ichthyodectidae indet.).[10]

See also

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Footnotes

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  1. ^ 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.
  2. ^ Kieft, R.L., Hampton, G.J., Jackson, C.A.-L., and Larsen, E., 2011. Stratigraphic architecture of a net-transgressive marginal- to shallow-marine succession: Upper Almond Formation, Rock Springs Uplift, Wyoming, U.S.A. Journal of Sedimentary Research, vol. 81, p. 513-533.
  3. ^ 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.
  4. ^ Stockey, R.A., Rothwell, G.W., and Johnson, K.R., 2007. Cobbania corrugata gen. et. comb. nov. (Araceae): A floating aquatic monocot from the Upper Cretaceous of western North America. American Journal of Botany, vol. 94, no. 4, p. 609-624.
  5. ^ a b c d e f g h i j "3.12 Wyoming, United States; 4. Almond Formation," in Weishampel, et al. (2004). Page 584.
  6. ^ Gates, T. A.; Farke, A. A. (2009-10-01). "Biostratigraphic and biogeographic implications of a hadrosaurid (Ornithopoda: Dinosauria) from the Upper Cretaceous Almond Formation of Wyoming, USA". Cretaceous Research. 30 (5): 1157–1163. doi:10.1016/j.cretres.2009.05.001. ISSN 0195-6671.
  7. ^ a b Listed as "cf. Thescelosaurus sp." in "3.12 Wyoming, United States; 4. Almond Formation," in Weishampel, et al. (2004). Page 584.
  8. ^ Listed as "?Anchiceratops sp." in "3.12 Wyoming, United States; 4. Almond Formation," in Weishampel, et al. (2004). Page 584.
  9. ^ Dalman SG, Jasinski SE, Lucas SG (2022). "A new chasmosaurine ceratopsid from the Upper Cretaceous (Campanian) Farmington Member of the Kirtland Formation, New Mexico". New Mexico Museum of Natural History and Science Bulletin. 90: 127–153.
  10. ^ Cowgill, Ethan; Ashurst-mcgee, Logan; Storrs, Glenn; Johnson, Christopher L.; Affolter, Matthew D.; Law, Lane; Hawkins, Quinlan; Tamez-Galvan, Evan; Kosowatz, Luke (2021). "A PRELIMINARY REPORT ON NEW VERTEBRATE FOSSILS FROM THE LATE CRETACEOUS ALMOND FORMATION, WYOMING". Geological Society of America Abstracts with Programs. 53 (6). doi:10.1130/abs/2021AM-371282.

References

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  • Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.