Lance Formation

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title: "Lance Formation" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["geology-of-the-rocky-mountains", "cretaceous-geology-of-wyoming", "geologic-formations-of-north-dakota", "natural-history-of-wyoming", "natural-history-of-north-dakota", "maastrichtian-stage-of-north-america", "fluvial-deposits", "sandstone-formations-of-the-united-states", "shale-formations-of-the-united-states", "siltstone-formations-of-the-united-states", "lance-formation", "geologic-formations-of-wyoming"] description: "Geological formation in the United States" topic_path: "science/earth-science" source: "https://en.wikipedia.org/wiki/Lance_Formation" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Geological formation in the United States ::

::data[format=table title="Infobox rockunit"]

Field	Value
name	Lance Formation
image	Lance Fm.jpg
caption	Badlands in the Lance Formation along Cow Creek near the type locality, Niobrara County, Wyoming
type	Sedimentary
age	Maastrichtian
~
period	Maastrichtian
prilithology	Sandstone, siltstone, shale
namedfor	Lance Creek, Wyoming
region	Wyoming
country	United States
underlies	Fort Union Formation
overlies	Meeteetse Formation
thickness	up to 600 m
map	Lance-map.jpg
map_caption	Outcrops of the Lance Formation in Wyoming
::

| name = Lance Formation | image = Lance Fm.jpg | caption = Badlands in the Lance Formation along Cow Creek near the type locality, Niobrara County, Wyoming | type = Sedimentary | age = Maastrichtian ~ | period = Maastrichtian | prilithology = Sandstone, siltstone, shale | otherlithology = | namedfor = Lance Creek, Wyoming | namedby = | region = Wyoming | country = United States | coordinates = | unitof = | subunits = | underlies = Fort Union Formation | overlies = Meeteetse Formation | thickness = up to 600 m | extent = | area = | map = Lance-map.jpg | map_caption = Outcrops of the Lance Formation in Wyoming ::figure[src="https://upload.wikimedia.org/wikipedia/commons/4/49/Coal_Stratigraphy_Powder_River_Basin.png" caption="Lance Formation – stratigraphy"] ::

The Lance (Creek) Formation is a division of Late Cretaceous (dating to about 69–66 Ma) rocks in the western United States. Named after Lance Creek, Wyoming, the microvertebrate fossils and dinosaurs represent important components of the latest Mesozoic vertebrate faunas. The Lance Formation is Late Maastrichtian in age (Lancian land mammal age), and shares much fauna with the Hell Creek Formation of Montana and North Dakota, the Frenchman Formation of southwest Saskatchewan, and the lower part of the Scollard Formation of Alberta.

The Lance Formation occurs above the Baculites clinolobatus ammonite marine zone in Wyoming, the top of which has been dated to about 69 million years ago, and extends to the K-Pg boundary, 66 million years ago. However, the characteristic land vertebrate fauna of the Lancian age (which take its name from this formation) is only found in the upper strata of the Lance, roughly corresponding to the thinner equivalent formations such as the Hell Creek Formation, the base of which has been estimated at 66.8 million years old.

Description

The formation is described by W.G. Pierce as thick-bedded, buff-colored sandstone, and drab to green shale. It is Upper Cretaceous in age.

The formation varies in thickness from about 90 m (300 ft.) in North Dakota, to almost 600 m (2,000 ft.) in parts of Wyoming.

Depositional environment

The Lance Formation was laid down by streams, on a coastal plain along the edge of the Western Interior Seaway. The climate was subtropical; there was no cold season and probably ample precipitation.

Paleontology

At least tens of thousands of Late Cretaceous vertebrate remains have been recovered from the Lance Formation. Fossils ranging from microscopic elements to extensive bonebeds, with nearly complete, sometimes articulated dinosaur skeletons, have been found. Most other animals known from the formation are freshwater animals, and some are exclusively freshwater forms (for instance, frogs and salamanders). However, marine fossils are also found in the formation, suggesting that the sea was nearby. The bird fauna is mainly composed of orders still existing today.

Coelurosaurs

Birds

::data[format=table]

Birds reported from the Lance Formation	Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
"Asteriornis-like bird"	Indeterminate			UCMP 143274, a fragmentary mandible	Previously identified as a parrot, then Caenagnathidae, but lacks the distinctive mandibular grooves, which appear early in development and present even in the smallest members of the latter. Larger than Asteriornis itself.
::

Other coelurosaurs

An isolated tooth crown of an indeterminate coelurosaur is recovered from the formation. ::data[format=table]

Miscellaneous coelurosaurs of the Lance Formation	Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
Trierarchuncus	cf. T. prairiensis				An alvarezsaurid originally identified from the Hell Creek Formation.
Troodontinae	Indeterminate			YPM VP 004691	Not referrable to Paronychodon or Pectinodon.
cf. Microraptoria	Indeterminate				Potentially the youngest microraptorian specimens, but YPM VP 865 may belong to the Unenlagiinae or Halszkaraptorinae.
Eudromaeosauria	Indeterminate			YPM VPPU 20589
::

Ornithischia

Ankylosaurs

::data[format=table]

Ankylosaurs of the Lance Formation	Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
				More than 70 osteoderms and a tooth
Denversaurus	D. schlessmani	Wyoming		FPDM-V9673, formerly BHI 127327	armor]]-plated dinosaur from the Latest Cretaceous of South Dakota, the last survivor of the nodosaurians, with comments on Stegosaur-Nodosaur relationships. Hunteria 1(3):1–23.(1988).
::

Marginocephalians

::data[format=table]

Marginocephalians reported from the Lance Formation	Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
					A ceratopsian
					A ceratopsid, also found in the Evanston, Frenchman, Hell Creek, Laramie, and Scollard Formations. Synonyms with type specimens from this formation include T. ingens and T. sulcatus.
::

Ornithopods

Indeterminate lambeosaurinae fossils have been found in the Lance Formation. ::data[format=table]

Ornithopods of the Lance Formation	Genus	Species	Location	Stratigraphic Position	Abundance	Notes	Images
					journal=PLOS ONE	volume=15	issue=5
::

Other vertebrates

Other land vertebrates include pterosaurs (e.g. cf. Quetzalcoatlus), crocodiles, champsosaurs, lizards, snakes, turtles, frogs and salamanders.

Remains of fishes and mammals (i.e. Nanocuris) have also been found in the Lance Formation.

References

References

1. (2006). "First isotopic (U-Pb) age for the Late Cretaceous ''Alamosaurus'' vertebrate fauna of west Texas, and its significance as a link between two faunal provinces". Journal of Vertebrate Paleontology.
2. Pierce, W.G., 1997, Geologic map of the Cody 1 degree x 2 degrees quadrangle, northwestern Wyoming: U.S. Geological Survey, Miscellaneous Geologic Investigations Map I-2500, scale 1:250000.
3. Silver, Mark (August 2, 2014) [http://www.amerisurv.com/content/view/12917/153/ "The Dinosaur Surveyors"] ''The American Surveyor'' Frederick Maryland
4. Federico L. Agnolin. (2010). "An avian coracoid from the Upper Cretaceous of Patagonia, Argentina". Stvdia Geologica Salmanticensia.
5. Nicholas R. Longrich. (2011). "''Titanoceratops ouranous'', a giant horned dinosaur from the Late Campanian of New Mexico". Cretaceous Research.
6. (2009). "An ornithurine-dominated avifauna from the Belly River Group (Campanian, Upper Cretaceous) of Alberta, Canada". Cretaceous Research.
7. (2000). "An avian quadrate from the Late Cretaceous Lance Formation of Wyoming". Journal of Vertebrate Paleontology.
8. "Table 11.1," in Weishampel, et al. (2004). Page 215.
9. (1980). "Presbyornis and the Origin of the Anseriformes (Aves: Charadriomorphae)". Smithsonian Contributions to Zoology.
10. Hope, S.. (2002). "Mesozoic Birds: Above the Heads of Dinosaurs". University of California Press.
11. (2002). "Mesozoic Birds, above the heads of Dinosaurs". University of California Press.
12. (2011). "A Galloanserine Quadrate from the Late Cretaceous Lance Formation of Wyoming". The Auk.
13. Brownstein, C. D.. (2024). "A juvenile bird with possible crown-group affinities from a dinosaur-rich Cretaceous ecosystem in North America". BMC Ecology and Evolution.
14. (25 December 2025). "Mandibular morphology clarifies phylogenetic relationships near the origin of crown birds". BMC Ecology and Evolution.
15. (1998). "A lower jaw from a Cretaceous parrot". Nature.
16. (1999). "Did parrots exist in the Cretaceous period?". Nature.
17. Waterhouse, D. M.. (2006). "Parrots in a nutshell: The fossil record of Psittaciformes (Aves)". Historical Biology.
18. "Table 6.1," in Weishampel, et al. (2004). Page 139.
19. (October 2013). "New Examples of Tyrannosaurus rex from the Lance Formation of Wyoming, United States". Bulletin of the Peabody Museum of Natural History.
20. The Dinosauria 2nd Edition (David B. Weishampel, Halszka Osmólska and Peter Dodson), p. 584-585, Dinosaur Distribution (DAVID B. WEISHAMPEL, PAUL M. BARRETT, RODOLFO A. CORIA, JEAN LE LOEUFF, XU XING, ZHAO XIJIN, ASHOK SAHNI, ELIZABETH M. P. GOMANI, CHRISTOPHER R. NOTO)
21. (2016). "Transfer of museum collection from the Hayashibara Museum of Natural Sciences to the Fukui Prefectural Dinosaur Museum". Memoir of the Fukui Prefectural Dinosaur Museum.
22. Greenfield, T.. (2021-07-22). "This should be a helpful reference for anyone wanting to reconstruct Denversaurus, this is the cervical armor arrangement of "Tank" (FPDM-V9673).".
23. (2013). "Pelvis of ''Gargoyleosaurus'' (Dinosauria: Ankylosauria) and the Origin and Evolution of the Ankylosaur Pelvis". PLOS ONE.
24. Bakker, R.T. (1988). Review of the Late Cretaceous nodosauroid Dinosauria: ''Denversaurus schlessmani'', a new [[Armour (zoology). armor]]-plated dinosaur from the Latest Cretaceous of South Dakota, the last survivor of the nodosaurians, with comments on Stegosaur-Nodosaur relationships. ''Hunteria'' 1(3):1–23.(1988).
25. (22 April 2011). "Spatial niche partitioning in dinosaurs from the latest cretaceous (Maastrichtian) of North America". Proceedings of the Royal Society B: Biological Sciences.
26. (1 January 2002). "Late Cretaceous dinosaurs from the Denver Basin, Colorado". Rocky Mountain Geology.
27. (July 1999). "Vertebrate faunal changes through Lancian and Puercan time in southern Wyoming". Journal of Paleontology.
28. (2002). "The Hell Creek Formation and the Cretaceous-Tertiary Boundary in the Northern Great Plains: An Integrated Continental Record of the End of the Cretaceous · Issue 361". Geological Society of America.
29. (September 2, 1986). "Latest Cretaceous Occurrence of Nodosaurid Ankylosaurs (Dinosauria, Ornithischia) in Western North America and the Gradual Extinction of the Dinosaurs". Journal of Vertebrate Paleontology.
30. "Table 23.1," in Weishampel, et al. (2004). Page 496.
31. Ostrom, John H.. (1978). "Leptoceratops gracilis from the "Lance" Formation of Wyoming". Journal of Paleontology.
32. "Table 17.1," in Weishampel, et al. (2004). Page 368.
33. (2009). "Extreme Cranial Ontogeny in the Upper Cretaceous Dinosaur Pachycephalosaurus". PLOS ONE.
34. (2010). "''Torosaurus'' Marsh, 1891, is ''Triceratops'' Marsh, 1889 (Ceratopsidae: Chasmosaurinae): Synonymy through ontogeny". Journal of Vertebrate Paleontology.
35. (January 2003). "Dinosaur skin fossils from this side of Hell, Wyoming: Paleoenvironmental implications of an upper cretaceous konservat-lagerstatte in the Lance formation". Journal of Vertebrate Paleontology.
36. Boyd, Clint A.. (2009). "Taxonomic revision of the basal neornithischian taxa ''Thescelosaurus'' and ''Bugenasaura''". Journal of Vertebrate Paleontology.
37. (2025-02-28). "''Infernodrakon hastacollis'' gen. et sp. nov., a new azhdarchid pterosaur from the Hell Creek Formation of Montana, and the pterosaur diversity of Maastrichtian North America". [[Journal of Vertebrate Paleontology]].

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