PBDB Taxon

Basic info	Taxonomic history	Classification	Included Taxa
Morphology	Ecology and taphonomy	External Literature Search	Age range and collections

Chasmosaurinae

Reptilia - Ceratopsidae

Taxonomy

Chasmosaurinae was named by Lambe (1915). It is not extant. Its type is Chasmosaurus.

It was assigned to Ceratopsia by Lambe (1915); and to Ceratopsidae by Lehman (1989), Dodson and Currie (1990), Lehman (1990), Godfrey and Holmes (1995), Lehman (1996), Dodson (1997), Dodson (1997), Sereno (1997), Eberth et al. (2001), Dodson et al. (2004), Farke (2004), Ryan and Evans (2005), Ryan and Russell (2005), Wu et al. (2007), Ryan (2007), Longrich (2010), Xu et al. (2010), Maidment and Barrett (2011), Farke et al. (2011), Longrich (2013), Longrich (2014), Mallon et al. (2014), Brown and Henderson (2015), Morschhauser et al. (2019) and Fowler and Freedman Fowler (2020).

Subtaxa

Agujaceratops, Anchiceratops, Arrhinoceratops, Bisticeratops, Bravoceratops, Ceratops (syn. Proceratops), Chasmosaurus (syn. Mojoceratops, Protorosaurus, Eoceratops) (type genus), Coahuilaceratops, Judiceratops, Kosmoceratops, Medusaceratops, Navajoceratops, Pentaceratops, Sierraceratops, Spiclypeus, Terminocavus, Triceratopsini, Utahceratops, Vagaceratops (syn. Mercuriceratops)

Synonyms

Ceratops montanus was named by Marsh (1888). Its type specimen is USNM 2411, a skull, and it is a 3D body fossil. Its type locality is Ceratops type site, Cow Creek, which is in a Campanian/Campanian terrestrial horizon in the Judith River Formation of Montana. It is the type species of Ceratops, Proceratops.

It was recombined as Proceratops montanus by Lull (1906); it was considered a nomen dubium by Ostrom and Wellnhofer (1986), Dodson and Currie (1990), Dodson (1990) and Penkalski and Dodson (1999); it was considered a nomen dubium by Dodson et al. (2004), Ryan (2007), Ryan et al. (2010) and Mallon et al. (2016).
Ceratops was named by Marsh (1888). Its type is Ceratops montanus. It is the type genus of Ceratopsidae, Ceratopsoidea, Ceratopsinae.

It was synonymized subjectively with Monoclonius by Baur (1891); it was synonymized subjectively with Agathaumas by Lydekker (1893); it was replaced with Proceratops by Lull (1906); it was considered a nomen dubium by Dodson and Currie (1990), Dodson (1990), Lehman (1990), Dodson et al. (2004), Ryan (2007) and Mallon et al. (2016).

It was assigned to Ceratopsia by Zittel (1890); to Stegosauria by Winkler (1893); to Ceratopsia by Gadow (1898); to Ceratopidae by Mansel-Pleydell (1902); to Ceratopsia by Gadow (1897) and Lull (1924); to Ceratopsinae by Nopcsa (1928), Huene (1950) and Tatarinov (1964); and to Ceratopsidae by Marsh (1888), Marsh (1888), Marsh (1895), Depéret (1896), Marsh (1896), Nopcsa (1901), Hay (1902), Hatcher et al. (1907), Huene (1909), Lambe (1911), von Zittel (1911), Brown (1914), Matthew (1915), Gilmore (1919), Gregory and Mook (1925), Huene (1927), Hay (1930), Lull (1933), Romer (1956), Kuhn (1964), Romer (1966), Charig (1967), Swinton (1970), Powell (1973), Laub (1979), Lehman (1981) and Ostrom and Wellnhofer (1986).
Proceratops was named by Lull (1906). Its type is Ceratops montanus.

It was synonymized subjectively with Ceratops by Hay (1930), Romer (1956) and Romer (1966).

It was assigned to Agathaumidae by Lull (1906).

Synonymy list

Year	Name and author
1888	Ceratops Marsh
1888	Ceratops montanus Marsh p. 477
1888	Ceratops Marsh p. 478
1890	Ceratops Zittel p. 751
1890	Ceratops montanus Zittel p. 751
1893	Ceratops Winkler p. 105
1893	Ceratops montanus Winkler p. 105
1895	Ceratops Marsh
1896	Ceratops Depéret p. 185
1896	Ceratops montanus Hatcher p. 113
1896	Ceratops Marsh p. 243
1897	Ceratops Gadow p. 205
1898	Ceratops Gadow p. 23
1900	Ceratops montanus Walcott p. 23
1901	Ceratops Nopcsa p. 216
1901	Ceratops montanus Nopcsa p. 216
1902	Ceratops Hay p. 500
1902	Ceratops montanus Hay p. 500
1902	Ceratops Mansel-Pleydell p. lxxxiv
1902	Ceratops montanus Mansel-Pleydell p. lxxxv
1906	Proceratops Lull p. 144
1906	Proceratops montanus Lull p. 144
1907	Ceratops Hatcher et al. p. 11
1907	Ceratops montanus Hatcher et al. pp. 100, 172
1909	Ceratops Huene p. 18
1910	Ceratops monatus Lull p. 772
1911	Ceratops Lambe p. 9
1911	Ceratops von Zittel p. 296
1914	Ceratops Brown p. 377
1915	Ceratops montanus Lambe p. 10
1915	Chasmosaurinae Lambe p. 20
1915	Ceratops Matthew p. 30
1919	Ceratops Gilmore p. 64
1924	Ceratops Lull p. 245
1925	Ceratops Gregory and Mook p. 5
1927	Ceratops Huene p. 259
1927	Ceratops montanus Huene p. 261
1928	Ceratops Nopcsa p. 185
1930	Ceratops monatus Arldt p. 702
1930	Ceratops Hay p. 223
1930	Ceratops montanus Hay p. 223
1930	Ceratops montanus Russell p. 142
1931	Ceratops montanus Johnson p. 368
1933	Ceratops Lull p. 96
1933	Ceratops montanus Lull p. 96
1950	Ceratops Huene p. 351
1956	Ceratops Romer p. 639
1964	Ceratops Kuhn p. 55
1964	Ceratops montanus Kuhn p. 55
1964	Ceratops montanus Russell p. 10
1964	Ceratops Tatarinov p. 585
1964	Ceratops montanus Tatarinov p. 585
1966	Ceratops Romer p. 371
1967	Ceratops Charig p. 717
1970	Ceratops Swinton p. 254
1973	Ceratops Powell p. 118
1979	Ceratops Laub p. 4
1979	Ceratops montanus Laub p. 4
1981	Ceratops Lehman p. 207
1986	Ceratops Ostrom and Wellnhofer p. 116
1989	Chasmosaurinae Lehman p. 138
1990	Chasmosaurinae Dodson and Currie p. 612
1990	Chasmosaurinae Lehman p. 212
1995	Chasmosaurinae Godfrey and Holmes p. 727
1996	Chasmosaurinae Lehman p. 505 fig. 10
1997	Chasmosaurinae Dodson p. 12
1997	Chasmosaurinae Sereno p. 443
2001	Chasmosaurinae Eberth et al. p. 59
2001	Ceratops montanus Horner et al. p. 10
2004	Chasmosaurinae Dodson et al. p. 495
2004	Chasmosaurinae Farke p. 5
2005	Chasmosaurinae Ryan and Evans pp. 323-324
2005	Chasmosaurinae Ryan and Russell p. 1381 fig. 10
2007	Chasmosaurinae Ryan p. 391 fig. 12
2007	Chasmosaurinae Wu et al. p. 1261 fig. 14
2010	Chasmosaurinae Longrich p. 692 fig. 10
2010	Chasmosaurinae Xu et al. p. 1634 fig. 3
2011	Chasmosaurinae Farke et al. p. 699
2011	Chasmosaurinae Maidment and Barrett p. 4
2013	Chasmosaurinae Longrich
2014	Chasmosaurinae Longrich p. 303 fig. 8
2014	Chasmosaurinae Mallon et al.
2015	Chasmosaurinae Brown and Henderson
2019	Chasmosaurinae Morschhauser et al. p. 129 fig. 10
2020	Chasmosaurinae Fowler and Freedman Fowler

Is something missing? Join the Paleobiology Database and enter the data

Rank	Name	Author
kingdom	Animalia	()
—	Bilateria
—	Eubilateria	Ax 1987
—	Deuterostomia
phylum	Chordata	Haeckel 1874
subphylum	Vertebrata
superclass	Gnathostomata
—	Osteichthyes	()
subclass	Sarcopterygii	()
subclass	Dipnotetrapodomorpha	(Nelson 2006)
subclass	Tetrapodomorpha	()
—	Tetrapoda
—	Reptiliomorpha
—	Anthracosauria
subclass	Amphibiosauria	Kuhn 1967
—	Cotylosauria	()
—	Amniota
—	Sauropsida
class	Reptilia
subclass	Eureptilia	()
—	Romeriida
—	Diapsida	()

Rank	Name	Author
—	Archosauromorpha	(Huene 1946)
—	Crocopoda
—	Archosauriformes	Gauthier 1986
—	Eucrocopoda
—	Archosauria	()
informal	Avemetatarsalia
—	Ornithodira
—	Dinosauromorpha
—	Dinosauriformes
—	Dinosauria	()
—	Ornithischia	()
—	Genasauria
—	Cerapoda
—	Marginocephalia
—	Ceratopsia	()
infraorder	Neoceratopsia
—	Coronosauria
superfamily	Ceratopsoidea
family	Ceratopsidae
subfamily	Chasmosaurinae
subfamily	Chasmosaurinae

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

Subfm. †Chasmosaurinae Lambe 1915

show all | hide all

G. †Agujaceratops Lucas et al. 2006 [Aguja horned face]

†Agujaceratops mariscalensis Lehman 1989

G. †Anchiceratops Brown 1914

†Anchiceratops ornatus Brown 1914

Invalid names: Anchiceratops longirostris Sternberg 1926 [synonym]

G. †Arrhinoceratops Parks 1925

†Arrhinoceratops brachyops Parks 1925

G. †Bisticeratops Dalman et al. 2022

†Bisticeratops froeseorum Dalman et al. 2022

G. †Bravoceratops Wick and Lehman 2013

†Bravoceratops polyphemus Wick and Lehman 2013

G. †Chasmosaurus Lambe 1914

†Chasmosaurus belli Lambe 1902

†Chasmosaurus russelli Sternberg 1940

Invalid names: Mojoceratops perifania Longrich 2010 [synonym]

Invalid names: Chasmosaurus brevirostris Lull 1933 [nomen dubium], Chasmosaurus kaiseni Brown 1933 [nomen dubium], Eoceratops Lambe 1915 [synonym], Mojoceratops Longrich 2010 [synonym], Monoclonius canadensis Lambe 1902 [nomen dubium], Protorosaurus Lambe 1914 [synonym]

G. †Coahuilaceratops Loewen et al. 2010

†Coahuilaceratops magnacuerna Loewen et al. 2010

G. †Judiceratops Longrich 2013

†Judiceratops tigris Longrich 2013

G. †Kosmoceratops Sampson et al. 2010

†Kosmoceratops richardsoni Sampson et al. 2010

G. †Medusaceratops Ryan et al. 2010

†Medusaceratops lokii Ryan et al. 2010

G. †Navajoceratops Fowler and Freedman Fowler 2020

†Navajoceratops sullivani Fowler and Freedman Fowler 2020

G. †Pentaceratops Osborn 1923

†Pentaceratops sternbergii Osborn 1923

Invalid names: Pentaceratops fenestratus Wiman 1930 [synonym]

G. †Sierraceratops Dalman et al. 2022

†Sierraceratops turneri Dalman et al. 2022

G. †Spiclypeus Mallon et al. 2016

†Spiclypeus shipporum Mallon et al. 2016

G. †Terminocavus Fowler and Freedman Fowler 2020

†Terminocavus sealeyi Fowler and Freedman Fowler 2020

Unr. †Triceratopsini Longrich 2011

G. †Eotriceratops Wu et al. 2007

†Eotriceratops xerinsularis Wu et al. 2007

G. †Regaliceratops Brown and Henderson 2015

†Regaliceratops peterhewsi Brown and Henderson 2015

G. †Titanoceratops Longrich 2011

†Titanoceratops ouranos Longrich 2011

G. †Torosaurus Marsh 1891

†Torosaurus latus Marsh 1891

Invalid names: Torosaurus gladius Marsh 1891 [objective synonym]

†Torosaurus utahensis Gilmore 1946

G. †Triceratops Marsh 1889

†Triceratops horridus Marsh 1889

Invalid names: Nedoceratops hatcheri Lull 1905 [synonym], Triceratops albertensis Sternberg 1949 [synonym], Triceratops brevicornus Hatcher and Lull 1905 [synonym], Triceratops calicornis Marsh 1898 [synonym], Triceratops elatus Marsh 1891 [synonym], Triceratops eurycephalus Schlaikjer 1935 [synonym], Triceratops flabellatus Marsh 1889 [synonym], Triceratops obtusus Marsh 1898 [synonym], Triceratops serratus Marsh 1890 [synonym]

†Triceratops prorsus Marsh 1890

Invalid names: Nedoceratops Ukrainsky 2007 [synonym], Ojoceratops Sullivan and Lucas 2010 [synonym], Sterrholophus Marsh 1891 [synonym], Tatankaceratops Ott and Larson 2010 [synonym], Triceratops sulcatus Marsh 1890 [nomen dubium]

G. †Utahceratops Sampson et al. 2010

†Utahceratops gettyi Sampson et al. 2010

G. †Vagaceratops Sampson 2010

†Vagaceratops irvinensis Holmes et al. 2001

Invalid names: Mercuriceratops gemini Ryan et al. 2014 [synonym], Pentaceratops aquilonius Longrich 2014 [synonym]

Invalid names: Mercuriceratops Ryan et al. 2014 [synonym]

Invalid names: Ceratops Marsh 1888 [nomen dubium]

Diagnosis

Reference	Diagnosis
S. C. R. Maidment and P. M. Barrett 2011	Modified from Lehman (1989): large ceratopsian dinosaurs with long, low facial region (preorbital length/height ratio = 1.4 to 3.0); inter-premaxillary fossae present; premaxilla and predentary with horizontal or poorly developed lateral cutting flange; nasal horn core, if present, small and formed in part by a separate ossification (epinasal); postfrontal foramen present; frontoparietal fontanelle walled mostly by the postorbital bones; frontal bones reduced; prefrontal bones small; cranial frill long (0.94 to 1.70 basal length of skull, except in Triceratops); triangular squamosal bones (length/height ratio = 2.0 to 3.5); prominent longitudinal channel in ventral surface of sacrum; triangular acromial process of the scapula arises about half way along the scapula blade; deep triceps fossa on the caudolateral deltopectoral crest of the humerus; foramen on the caudomedial humerus located dorsal to the apex of the deltopectoral crest; strongly curved ischium.