PBDB Taxon

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Triceratops

Reptilia - Ceratopsidae

Taxonomy

Triceratops was named by Marsh (1889). Its type is Ceratops horridus. It is the type genus of Triceratopsini.

It was synonymized subjectively with Agathaumas by Baur (1891) and Lydekker (1893).

It was assigned to Ceratopsia by Zittel (1890); to Scelidosauria by Seeley (1892); to Ceratopsia by Gadow (1898) and Gadow (1901); to Ceratopidae by Mansel-Pleydell (1902); to Agathaumidae by Lull (1906); to Eoceratopsinae by Lambe (1915); to Monocloninae by Tatarinov (1964); to Ceratopsia by Marsh (1890), Winkler (1893), Gadow (1897), Tornier (1913), Lull (1924) and Ostrom (1965); to Ceratopinae by Olshevsky and Ford (1994); to Ceratopsinae by Nopcsa (1928), Huene (1950) and Sereno (1998); to Ceratopsidae by Marsh (1889), Marsh (1891), Marsh (1895), Depéret (1896), Marsh (1896), Lambe (1899), Nopcsa (1901), Hay (1902), Lambe (1905), Hatcher et al. (1907), Huene (1909), von Zittel (1911), Brown (1914), Brown (1914), Matthew (1915), Joleaud (1922), Gregory and Mook (1925), Huene (1927), Hay (1930), Russell (1930), Lull (1933), Chakravarti (1934), Sternberg (1949), Romer (1956), Parsch (1963), Kuhn (1964), Estes (1964), Romer (1966), Charig (1967), Swinton (1970), Madsen and Miller (1979), Lehman (1981), McIntosh (1981), McGinnis (1982), Russell (1984), Breithaupt (1985), Ostrom and Wellnhofer (1986), Clemens (1986), Tokaryk (1986), Carroll (1988), Eberth (1997), Makovicky (2001) and You and Dodson (2003); to Chasmosaurinae by Dodson and Currie (1990), Lehman (1990), Lehman (1996), Forster (1996), Vickaryous and Ryan (1997), Dodson (1997), Dodson (1997), Dodson et al. (2004), Farke (2004), Diem and Archibald (2005), Wu et al. (2007), Ryan (2007), Hunt and Lehman (2008), Scannella and Horner (2010), Longrich (2010), Xu et al. (2010), Ryan et al. (2010), Farke (2011), Maidment and Barrett (2011), Fiorillo and Tykoski (2012) and Longrich and Field (2012); and to Triceratopsini by Longrich (2014).

Species

Ojoceratops fowleri, Tatankaceratops sacrisonorum, T. horridus (syn. T. albertensis, T. elatus, T. brevicornus, T. serratus, Nedoceratops hatcheri, T. obtusus, T. flabellatus, T. eurycephalus, T. calicornis), T. prorsus, T. sulcatus

Synonyms

Diceratus was named by Mateus (2008).

It was synonymized subjectively with Triceratops by Hunt and Lehman (2008) and Scannella and Horner (2010); it was synonymized subjectively with Nedoceratops by Farke (2011).

It was assigned to Ceratopsidae by Mateus (2008).
Nedoceratops was named by Ukrainsky (2007).

It was synonymized subjectively with Triceratops by Scannella and Horner (2010), Scannella and Horner (2011), Longrich and Field (2012) and Longrich (2014).

It was assigned to Ceratopsidae by Ukrainsky (2007); and to Chasmosaurinae by Farke (2011).
Ojoceratops was named by Sullivan and Lucas (2010).

It was synonymized subjectively with Triceratops by Longrich (2014).

It was assigned to Chasmosaurinae by Sullivan and Lucas (2010), Jasinski et al. (2011) and Maidment and Barrett (2011); and to Ceratopsidae by Jasinski (2015).
Tatankaceratops was named by Ott and Larson (2010). Its type is Tatankaceratops sacrisonorum.

It was synonymized subjectively with Triceratops by Longrich (2014).

It was assigned to Chasmosaurinae by Ott and Larson (2010) and Maidment and Barrett (2011).
Triceratops sulcatus was named by Marsh (1890). Its type specimen is USNM 4276 and is a 3D body fossil. Its type locality is west side, Lance Creek, which is in a Maastrichtian terrestrial horizon in the Lance Formation of Wyoming.

It was considered a nomen dubium by Lull (1933); it was considered a nomen dubium by Ostrom and Wellnhofer (1986), Dodson and Currie (1990), Ostrom and Wellnhofer (1990) and Dodson et al. (2004).
Sterrholophus was named by Marsh (1891).

It was synonymized subjectively with Torosaurus by Huene (1909); it was synonymized subjectively with Triceratops by Hatcher et al. (1907), von Zittel (1911), Kuhn (1964), Romer (1966), Ostrom and Wellnhofer (1986), Dodson and Currie (1990) and Farke (2011).

It was assigned to Ceratopidae by Mansel-Pleydell (1902); and to Ceratopsidae by Marsh (1891), Marsh (1895), Marsh (1896), Nopcsa (1901), Hay (1902), Lambe (1905), Romer (1956) and Tatarinov (1964).
Diceratops was named by Hatcher and Lull (1905) [name vide Hatcher & Lull 1905; name also given as "gen. nov." in Hatcher et al. 1907.].

It was synonymized subjectively with Triceratops by Tatarinov (1964), Ostrom and Wellnhofer (1986), Dodson and Currie (1990), Derstler (1994) and Longrich (2010); it was replaced with Diceratus by Mateus (2008) and Hunt and Lehman (2008); it was replaced with Nedoceratops by Ukrainsky (2007) and Farke (2011).

It was assigned to Agathaumidae by Lull (1906); to Eoceratopsinae by Lambe (1915); to Ceratopsia by Hatcher and Lull (1905), Tornier (1913) and Lull (1924); to Ceratopsinae by Nopcsa (1928) and Huene (1950); to Ceratopsidae by Hatcher et al. (1907), Huene (1909), von Zittel (1911), Joleaud (1922), Gregory and Mook (1925), Huene (1927), Hay (1930), Russell (1930), Romer (1956), Kuhn (1964), Romer (1966), Russell (1984) and Clemens (1986); and to Chasmosaurinae by Forster (1996), Dodson et al. (2004), Wu et al. (2007), Xu et al. (2010) and Ryan et al. (2010).

Synonymy list

Year	Name and author
1889	Triceratops Marsh pp. 173-174
1890	Triceratops sulcatus Marsh
1890	Triceratops Marsh p. 418
1890	Triceratops sulcatus Marsh p. 422
1890	Triceratops Zittel p. 752
1890	Triceratops sulcatus Zittel p. 753
1891	Sterrholophus Marsh
1891	Triceratops Marsh p. 265
1891	Sterrholophus Marsh pp. 339-340
1892	Triceratops Seeley
1893	Triceratops Winkler p. 109
1895	Sterrholophus Marsh
1895	Triceratops Marsh
1896	Triceratops Depéret p. 185
1896	Sterrholophus Marsh p. 243
1896	Triceratops Marsh p. 243
1897	Triceratops Gadow p. 205
1898	Triceratops Gadow p. 23
1899	Triceratops Lambe p. 187
1900	Triceratops sulcatus Walcott p. 23
1901	Triceratops Gadow p. 430
1901	Sterrholophus Nopcsa p. 217
1901	Triceratops Nopcsa p. 217
1901	Triceratops sulcatus Nopcsa p. 217
1902	Triceratops Hay p. 498
1902	Sterrholophus Hay p. 499
1902	Triceratops sulcatus Hay p. 499
1902	Sterrholophus Mansel-Pleydell p. lxxxiv
1902	Triceratops Mansel-Pleydell p. lxxxiv
1902	Triceratops sulcatus Mansel-Pleydell p. lxxxv
1905	Diceratops Hatcher and Lull p. 417
1905	Triceratops Lambe p. 23
1905	Sterrholophus Lambe p. 24
1906	Diceratops Lull p. 144
1906	Triceratops Lull p. 144
1907	Triceratops Hatcher et al. p. 12
1907	Diceratops Hatcher et al. p. 168
1907	Triceratops sulcatus Hatcher et al. p. 170
1909	Diceratops Huene p. 18
1909	Triceratops Huene p. 18
1911	Diceratops von Zittel p. 296
1911	Triceratops von Zittel p. 296
1913	Diceratops Tornier p. 375
1913	Triceratops Tornier p. 375
1914	Triceratops Brown p. 377
1914	Triceratops sulcatus Brown p. 542
1914	Triceratops Brown p. 543
1914	Triceratops sulcatus Huene p. 584
1915	Diceratops Lambe p. 18
1915	Triceratops Lambe p. 20
1915	Triceratops Matthew p. 30
1920	Triceratops sulcatus Pompeckj p. 114
1922	Triceratops Joleaud p. 64
1922	Diceratops Joleaud p. 65
1924	Diceratops Lull p. 244
1924	Triceratops Lull p. 244
1925	Triceratops Gregory and Mook pp. 4-6
1925	Diceratops Gregory and Mook p. 6
1927	Diceratops Huene p. 261
1927	Triceratops Huene p. 261
1927	Triceratops sulcatus Huene p. 261
1928	Diceratops Nopcsa p. 185
1928	Triceratops Nopcsa p. 185
1930	Diceratops Hay p. 226
1930	Triceratops Hay p. 227
1930	Triceratops sulcatus Hay p. 230
1930	Diceratops Russell p. 140
1930	Triceratops Russell p. 140
1930	Triceratops sulcatus Russell p. 140
1933	Triceratops Lull p. 114
1934	Triceratops Chakravarti p. 78
1940	Triceratops sulcatus Brown and Schlaikjer p. 4 fig. 3
1949	Triceratops Sternberg p. 41 fig. 1
1950	Diceratops Huene p. 351
1950	Triceratops Huene p. 351
1956	Diceratops Romer p. 639
1956	Sterrholophus Romer p. 639
1956	Triceratops Romer p. 639
1963	Triceratops Parsch p. 8
1964	Triceratops Estes p. 145
1964	Diceratops Kuhn p. 56
1964	Triceratops Kuhn p. 59
1964	Triceratops sulcatus Kuhn p. 59
1964	Triceratops Tatarinov p. 583
1964	Sterrholophus Tatarinov p. 585
1965	Triceratops Ostrom p. 39
1965	Triceratops sulcatus Ostrom p. 39
1966	Diceratops Romer p. 371
1966	Triceratops Romer p. 371
1967	Triceratops Charig p. 717
1970	Triceratops Swinton p. 254
1979	Triceratops Madsen and Miller p. 5
1981	Triceratops Lehman p. 207
1981	Triceratops McIntosh p. 41
1982	Triceratops McGinnis p. 106
1984	Diceratops Russell p. 27
1984	Triceratops Russell p. 27
1985	Triceratops Breithaupt p. 167
1986	Diceratops Clemens p. 80
1986	Triceratops Clemens p. 80
1986	Triceratops Ostrom and Wellnhofer p. 156
1986	Triceratops Tokaryk p. 193
1988	Triceratops Carroll
1990	Triceratops Dodson and Currie p. 612
1990	Triceratops Lehman p. 212
1994	Triceratops Olshevsky and Ford
1996	Diceratops Forster p. 261
1996	Triceratops Forster p. 268
1996	Triceratops Lehman p. 505 fig. 10
1997	Triceratops Dodson p. 12
1997	Triceratops Eberth p. 202
1997	Triceratops Vickaryous and Ryan p. 492
1998	Triceratops Sereno p. 62
2001	Triceratops Makovicky p. 254 fig. 18.3
2003	Triceratops You and Dodson
2004	Diceratops Dodson et al. p. 496
2004	Triceratops Dodson et al. p. 496
2004	Triceratops Farke p. 4
2005	Triceratops Diem and Archibald p. 251
2007	Triceratops Ryan p. 391 fig. 12
2007	Nedoceratops Ukrainsky p. 292
2007	Diceratops Wu et al. p. 1261 fig. 14
2007	Triceratops Wu et al. p. 1261 fig. 14
2008	Triceratops Hunt and Lehman p. 1132
2008	Diceratus Mateus p. 423
2010	Triceratops Longrich p. 692 fig. 10
2010	Tatankaceratops Ott and Larson p. 205
2010	Diceratops Ryan et al. p. 185
2010	Triceratops Ryan et al. p. 185
2010	Triceratops Scannella and Horner p. 1166
2010	Ojoceratops Sullivan and Lucas p. 171
2010	Diceratops Xu et al. p. 1634 fig. 3
2010	Triceratops Xu et al. p. 1634 fig. 3
2011	Nedoceratops Farke p. 3
2011	Triceratops Farke pp. 6-8
2011	Ojoceratops Jasinski et al. p. 253
2011	Ojoceratops Maidment and Barrett p. 3
2011	Tatankaceratops Maidment and Barrett p. 3
2011	Triceratops Maidment and Barrett p. 36
2012	Triceratops Fiorillo and Tykoski
2012	Triceratops Longrich and Field p. 9
2014	Triceratops Longrich p. 303 fig. 8
2015	Ojoceratops Jasinski p. 79

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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

Rank	Name	Author
—	Diapsida	()
—	Archosauromorpha	(Huene 1946)
—	Crocopoda
—	Archosauriformes	Gauthier 1986
—	Eucrocopoda
—	Archosauria	()
informal	Avemetatarsalia
—	Ornithodira
—	Dinosauromorpha
—	Dinosauriformes
—	Dinosauria	()
—	Ornithischia	()
—	Genasauria
—	Cerapoda
—	Marginocephalia
—	Ceratopsia	()
family	Ceratopsidae
subfamily	Chasmosaurinae
—	Triceratopsini
genus	Triceratops

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.

G. †Triceratops Marsh 1889

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†Triceratops horridus Marsh 1889

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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]

Diagnosis

Reference	Diagnosis
J. H. Ostrom and P. Wellnhofer 1986	Large ceratopsian with three facial horns – two large brow horns composed of postfrontals and frontals and a single nasal horn composed of a separate ossification or as an outgrowth of the nasals; lengths and curvature of horns vary; nasal horn size variable, but always shorter than brown horns, directed up and forward and usually not curved; brow horns project up and forward, and transverse or posterior curvature variable, but usually not present; frill short compared with some other ceratopsids (postorbital length = 1.1 to 1.4 times preorbital length), composed of parietals and long squamosals extending to posterior frill margin; frill margins now horned or bearing spikes, but may support blunt epoccipital bones; frill is not fenestrated except for small lateral and superior temporal fenestra proximally; postfrontal fontanelle usually closed; antorbital fenestra narrow and slit-like; external naris very large; large edentulous turtle-like beak composed of rostral and premaxillae above and predentary below; jugal expanded into a robust ventral process overlapping the quadrate; mandivle massive with a strong laterally placed coronoid process of the denture; teeth "two-rooted" and compressed into large longitudinal shearing batteries; twenty-four presacral vertebrae, including eight cervicals; first four cervicals co-ossified; lumbars lacking; sacral series includes posterior dorsals and proximal caudals up to a total of 10 or 11 segments; limbs as in other ceratopsids.
J. B. Scannella and J. R. Horner 2010	Skull bears elongate postorbital horn cores (derived from fusion of the postorbitals and prefrontals early in ontogeny) plus a single variable epinasal horn. Epinasal unites the rostral-nasal-premaxillae complex. The shape of the frontal fontanelle is variable, though generally circular when present; some specimens lack a frontal fontanelle as a result of closure of the frontals and parietal. Parietal-squamosal frill relatively short, broad, and fan-like (compared to other chasmosaurine genera). Fenestrated and expanded in mature individuals. Strong undulating midline parietal ridge throughout early ontogeny becomes a broad parietal bar in mature specimens; fenestrae are ovate to nearly circular. Pronounced squamosal bars alongside parietal-squamosal contacts in mature specimens. Epiparietals and episquamosals ornament posterior and lateral margins of the parietal-squamosal frill. Epijugals on the jugal ﬂange fuse the jugal-quadratojugal complex (modiﬁed from Ostrom and Wellnhofer, 1986, and Forster, 1996).
R. M. Sullivan and S. G. Lucas 2010 (Ojoceratops)	As for the type and only known species.
C. J. Ott and P. L. Larson 2010 (Tatankaceratops)	As for type species, by monotypy.
A. A. Farke 2011 (Nedoceratops)	As for the type and only species.

Measurements

No measurements are available

Composition:

hydroxyapatiteo

Entire body:

yesg

Adult length:

10 to < 100o

Adult width:

1.0 to < 10o

Adult height:

1.0 to < 10o

Maximum body mass:

10000 kgg

Minimum body mass:

3000 kgg

Architecture:

compact or denseo

Ontogeny:

accretion, modification of partso

Grouping:

gregariouso

Environment:

terrestrialsubo

Locomotion:

actively mobileo

Life habit:

ground dwellingsubo

Diet:

herbivoresubo

Reproduction:

oviparouso

Dispersal:

direct/internalo

Dispersal 2:

mobileo

Created:

2005-08-25 05:45:07

Modified:

2005-08-25 07:45:07

Source: g = genus, subo = suborder, o = order

References: Marsh 1875, Norman and Weishampel 1991, Peczkis 1995

Age range: base of the Maastrichtian to the top of the Lancian or 72.10000 to 66.00000 Ma

Collections (159 total)

Time interval	Ma	Country or state	Original ID and collection number
Late/Upper Campanian	83.5 - 70.6	Canada (Alberta)	T. horridus (162141)
Late/Upper Campanian - Maastrichtian	83.5 - 66.0	USA (New Mexico)	T. sp. (55286)
Maastrichtian	72.1 - 66.0	USA (Wyoming)	T. sp. (225318 225319)
Maastrichtian	72.1 - 66.0	USA (Montana)	T. elatus (49016) T. prorsus (173841) T. sp. (38544 55353 55355 64428 64429 100852 109660 109661 142376 189572 228491)
Maastrichtian	72.1 - 66.0	USA (South Dakota)	T. horridus (225317 225924) T. sp. (74175)
Lancian	70.6 - 66.0	USA (Colorado)	T. sp. (14640)
Lancian	70.6 - 66.0	Canada (Saskatchewan)	T. sp. (14558 128461)
Lancian	70.6 - 66.0	USA (Montana)	T. sp. (14516 14550 14615 14616 14649 81041 81042 144502 179991)
Lancian	70.6 - 66.0	USA (Wyoming)	Ceratopsia indet. (165877) T. sp. (14505 14527 14538 14557 14579 14601 14609 165878)
Lancian	70.6 - 66.0	USA (South Dakota)	T. sp. (14537 192251)
Lancian	70.6 - 66.0	USA (North Dakota)	T. sp. (137710 137728 224667)
Late/Upper Maastrichtian	70.6 - 66.0	USA (South Dakota)	Tatankaceratops sacrisonorum (97798) T. horridus (179969 224486) T. sp. (50082 124934 150890 150892 150893 179970 216603 224484 224488 224489 224490 224492)
Late/Upper Maastrichtian	70.6 - 66.0	USA (Utah)	T. sp. (48549)
Late/Upper Maastrichtian	70.6 - 66.0	Canada (Saskatchewan)	T. prorsus (152400 152401 228825 228826 228827) T. sp. (14555 54105 152399 225845) T. sp., T. prorsus (45675)
Late/Upper Maastrichtian	70.6 - 66.0	USA (North Dakota)	T. horridus (191374) T. prorsus (24851) T. sp. (45123 57919)
Late/Upper Maastrichtian	70.6 - 66.0	USA (Colorado)	Ceratopsia indet. (49527) T. sp. (49529 73927 182584)
Late/Upper Maastrichtian	70.6 - 66.0	Canada (Alberta)	T. albertensis (47127 47128)
Late/Upper Maastrichtian	70.6 - 66.0	USA (New Mexico)	Chasmosaurinae indet. (68042) Ojoceratops fowleri (47819 97795 97796 138833 171027)
Late/Upper Maastrichtian	70.6 - 66.0	USA (Montana)	T. horridus (217183) T. prorsus (14674 173842) T. sp. (13142 55354 67129 72143 88990 99441 109659 142326 157187 162855 179968 183109 183110 189003 221004 221005 221007 227182 227283)
Late/Upper Maastrichtian	70.6 - 66.0	USA (Wyoming)	Ceratops horridus (46119) Ceratopsia indet. (52089) Diceratops hatcheri (46133) T. brevicornus (46132 52683) T. calicornis (50931) T. elatus (46130 52682 52691 52692) T. eurycephalus (52107) T. flabellatus (46136 165876) T. obtusus (46131) T. prorsus (46127 46129 52690 52694 189513) T. serratus (46126) T. serratus, Ceratopsia indet. (52686) T. sp. (14585 26760 45878 50086 50087 52088 52681 52684 52687 52688 52693 52695 54177 54179 57161 57162 57166 57168 142325 164991 164992 164993 191271 226054 226055) T. sp., T. sulcatus (52685) T. sulcatus (46138 52689)