Genus
Valid Extinct

Chasmosaurus

Lambe 1914
Etymology Lézard à ouverture (fait référence à la collerette pourvue de très grandes fenêtres pariétales).

Chasmosaurus is a genus of ceratopsid dinosaur from the Late Cretaceous Period in North America. Its given name means 'opening lizard', referring to the large openings (fenestrae) in its frill. With a length of 4.3–4.8 metres (14.1–15.7 ft) and a weight of 1.5–2 tonnes —or anywhere from 2,200 to nearly 5,000 lbs—Chasmosaurus was of a slightly smaller to "average" size, especially when compared to larger ceratopsids.

Temporal range
Triassic
Jurassic
Cretaceous
Paleogene
Neogene
252 201 145 66 0 Ma
PBDB occurrences
21
Group
Dinosaures
Herbivore Ground dwelling Terrestrial
Chasmosaurus
click to enlarge
Chasmosaurus on display at the Royal Ontario Museum. © Eduard Solà · CC BY-SA 3.0 · Wikimedia
Chasmosaurus
Chasmosaurus
PBDB ↗ Wikipedia ↗
Classification
Dinosauria Unranked clade
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Ornithischia Unranked clade
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Neornithischia Unranked clade
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Pyrodontia Unranked clade
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Cerapoda Unranked clade
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Marginocephalia Unranked clade
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Ceratopsia Suborder
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Ceratopsidae Family
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Chasmosaurinae Subfamily
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Chasmosaurus Genus
Measurements
Length
4,6 m ⓘ
Chasmosaurus irvinensis — min connu
5,9 m ⓘ
Chasmosaurus belli — max connu
5 m ⓘ
Mass
1 000 kg ⓘ
Chasmosaurus irvinensis — min connu
2 100 kg ⓘ
Chasmosaurus belli — max connu
2 000 kg ⓘ
Fossil sites 21 geolocated sites
Distribution
Top countries
🇨🇦 Canada
20
🇺🇸 United States
1
Geological formations
Dinosaur Park
18
Oldman
1
Judith River
1
Temporal distribution
Campanian (83.6–72.2 Ma)
21
Species (6)
Chasmosaurus belli 84 Ma
Chasmosaurus brevirostris nomen dubium, species not entered Chasmosaurus 84 Ma
Chasmosaurus kaiseni nomen dubium, species not entered Chasmosaurus 84 Ma
Chasmosaurus russelli 84 Ma
Mojoceratops perifania subjective synonym of Chasmosaurus russelli 84 Ma
Monoclonius canadensis nomen dubium, species not entered Chasmosaurus 84 Ma
Synonyms (6)
Chasmosaurus brevirostris nomen dubium, species not entered Chasmosaurus
Chasmosaurus kaiseni nomen dubium, species not entered Chasmosaurus
Eoceratops subjective synonym of Chasmosaurus
Mojoceratops subjective synonym of Chasmosaurus
Monoclonius canadensis nomen dubium, species not entered Chasmosaurus
Protorosaurus subjective synonym of Chasmosaurus
Images 10
Bibliography
Original description
L. M. Lambe. 1914. On Gryposaurus notabilis, a new genus and species of trachodont dinosaur from the Belly River Formation of Alberta, with a description of the skull of Chasmosaurus belli. The Ottawa Naturalist 27(11):145-155
Bibliography (12)
J. A. Campbell, M. J. Ryan, and R. B. Holmes, C. J. Schröder-Adams. 2016. A re-evaluation of the chasmosaurine ceratopsid genus Chasmosaurus (Dinosauria: Ornithischia) from the Upper Cretaceous (Campanian) Dinosaur Park Formation of western Canada. PLoS ONE 11(1):e0145805:1-39 DOI ↗
T. Konishi. 2015. Redescription of UALVP 40, an unusual specimen of Chasmosaurus Lambe, 1914 (Ceratopsidae: Chasmosaurinae) bearing long postorbital horns, and its implications for ontogeny and alpha taxonomy of the genus. Canadian Journal of Earth Sciences 52(8):608-619 DOI ↗
S. C. R. Maidment and P. M. Barrett. 2011. A new specimen of Chasmosaurus belli (Ornithischia: Ceratopsidae), a revision of the genus, and the utility of postcrania in the taxonomy and systematics of ceratopsid dinosaurs. Zootaxa 2963:1-17 DOI ↗
N. R. Longrich. 2010. Mojoceratops perifania, a new chasmosaurine ceratopsid from the late Campanian of western Canada. Journal of Paleontology 84(4):681-694 DOI ↗
P. J. Currie and D. A. Russell. 2005. The geographic and stratigraphic distribution of articulated and associated dinosaur remains. Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed. Indiana University Press, Bloomington
S. J. Godfrey and R. Holmes. 1995. Cranial morphology and systematics of Chasmosaurus (Dinosauria: Ceratopsidae) from the Upper Cretaceous of western Canada. Journal of Vertebrate Paleontology 15(4):726-742 DOI ↗
A. K. Behrensmeyer. 1994.
A. R. Fiorillo. 1989. The vertebrate fauna from the Judith River Formation (Late Cretaceous) of Wheatland and Golden Valley counties, Montana. Mosasaur 4:127-142
C. M. Sternberg. 1940. Ceratopsidae from Alberta. Journal of Paleontology 14(5):468-480
B. Brown. 1933. A new longhorned Belly River ceratopsian. American Museum Novitates 669:1-3
R. S. Lull. 1933. A revision of the Ceratopsia or horned dinosaurs. Memoirs of the Peabody Museum of Natural History 3(3):1-175 DOI ↗
L. M. Lambe. 1902. New genera and species from the Belly River Series (mid-Cretaceous). Geological Survey of Canada Contributions to Canadian Palaeontology 3(2):25-81