Genus

Valid Extinct

Achelousaurus

Sampson 1994

Achelousaurus is a genus of centrosaurine ceratopsid dinosaur that lived during the Late Cretaceous Period of what is now North America, about 77 to 74.8 million years ago. The first fossils of Achelousaurus were collected in Montana in 1987, by a team led by Jack Horner, with more finds made in 1989. In 1994, Achelousaurus horneri was described and named by Scott D. Sampson; the generic name means "Achelous lizard", in reference to the Greek deity Achelous, and the specific name refers to Horner. The genus is known from a few specimens consisting mainly of skull material from individuals, ranging from juveniles to adults.

Temporal range

Triassic

Jurassic

Cretaceous

Paleogene

Neogene

252 201 145 66 0 Ma

PBDB occurrences

Group

Dinosaures

Herbivore Ground dwelling Terrestrial

click to enlarge

Achelousaurus horneri skull, collected in Glacier County, Montana, at the Museum of the Rockies in Bozeman, Montana. The Ceratopsidae are those dinosaurs with head frills. There are three large subgroups of Ceratopsidae: Centrosaurinae, Ceratopsinae, and Chasmosaurinae. The Triceratopsini are a "tribe" of the Chasmosaurinae -- a genus so vast that it gets the special name "tribe". The Pachyrhinosaurini are a "tribe" within the Centrosaurinae. Achelousaurus is a genus within the Pachyrhinosaurini. So far, only three skulls and some limited skeletal remains have been collected anywhere in the world -- and all of them in Montana. Their bony frills are quite similar to the Styracosaurus albertensis, although their other skull features (such as big bony bosses on the nose and behind the eyes) are not. © Tim Evanson from Washington, D.C., United States of America · CC BY-SA 2.0 · Wikimedia

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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Centrosaurinae Subfamily

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Pachyrhinosaurini Unranked clade

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Achelousaurus Genus

Fossil sites 2 geolocated sites

Distribution

Top countries

🇺🇸 United States

Geological formations

Two Medicine

Temporal distribution

Campanian (83.6–72.2 Ma)

Species (1)

Achelousaurus horneri 84 Ma

Bibliography

Original description

S. D. Sampson. 1994. Two new horned dinosaurs (Ornithischia: Ceratopsidae) from the Upper Cretaceous Two Medicine Formation, Montana, USA. Journal of Vertebrate Paleontology 14(3, suppl.):44A

Bibliography (2)

S. D. Sampson. 1995. Two new horned dinosaurs from the upper Cretaceous Two Medicine Formation of Montana; with a phylogenetic analysis of the Centrosaurinae (Ornithischia: Ceratopsidae). Journal of Vertebrate Paleontology 14(5):743-760 DOI ↗

S. D. Sampson. 1994. Two new horned dinosaurs (Ornithischia: Ceratopsidae) from the Upper Cretaceous Two Medicine Formation, Montana, USA. Journal of Vertebrate Paleontology 14(3, suppl.):44A