Species: ? alticornis (MARSH, 1887) HATCHER vide LULL, 1905/MARSH, HATCHER & LULL, 1907 (nomen dubium)
Etymology: Latin, alti, "tall, high" and Latin, cornus, "horn."
= Bison alticornis MARSH, 1887 (nomen dubium)
= Polyonax alticornis (MARSH, 1887) COPE, 1889 (nomen dubium)
= Ceratops alticornis (MARSH, 1887) MARSH, 1889 (nomen dubium)

Holotype: USNM 1817E (4739 MERRELL, 1907)

Locality: Unknown, Lakewood Gulch (old Green Mountain Creek, CARPENTER, 2006), near Denver, Denver County, Colorado.

Horizon: Denver Formation.

Biostratigraphy:

Age: Lancian age, Late Maastrichtian Stage, Upper Senonian Subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Horn cores.
Note: These horn cores were under Marsh's instructions to be broken and replastered to resemble those of a bison.

_____________________________________________________________________________________

Species: horridus (MARSH, 1889) MARSH, 1889
Etymology: Latin, horridus, "frightful."
= Ceratops horridus MARSH, 1889

Holotype: YPM 1820

Locality: Buck Creek, Converse County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Skull and jaws (Female).

Referred material:

ANDERSON, 1999

Locality: Bear Creek, 28-30 miles south and east of Fort Peck, McCone County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

University of Michigan, UM 17062: Basicranium and ribs.

 

ANONYMOUS, 1994

Locality: South Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Dakota Dinosaur Museum: Skull and skeleton.

 

ARMITAGE & ANDERSON, 2013

Locality: Private Ranch, E 1/2 of the SW 1/4 fo the NE 1/4 Section 14, T. 15 N., R. 56 E., Glendive, Dawson County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian Age, Late Maastrichtian Age, Late Senonian Subepoch, Late Gulf Epoch, Late Cretaceous.

Material:

HTCH-00: An intact supraorbital horn with soft sheets of fibrillar bone.

 

BJORK, 1985

Locality: Ruby Site in the northeastern Butte County, South Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Number: Not given:

 

CARPENTER, 1979

Locality: Weld County, Colorado.

Horizon: Laramie Formation.

Biostratigraphy:

Age: Lancian Age, upper Maastrichtian Stage, uppermost Senonian Subepoch, Upper Upper Gulf Epoch, Late Cretaceous.

Material:

UCM 38473: Left humerus, nasal horn, vertebrae, right coracoid, distal end of ?fibula, fragments of ribs, scapula, phalanges, brow horn, and unidentified bones.

 

D'ANASTASIO, CILLI, BACCHIA, FANTI, GOBBO & CAPASSO, 2022

Locality: Mud Butte Ranch, 45°03'11.26"N, 102°52'5o.582"W, southwestern Perkins County, South Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

"Big John": Fragmentary skull and skeleton.

Note: A lesion on the left squamosal.

DONNAN, 1995

Locality: North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

“Tara”: A relatively complete sub adult.

“Willie”: A perfect pelvis and ossified tendons to tip of tail.

 

EIN, 1993

Locality: A remote Ranch in Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Skeleton “Kevin”
Note: Found with a tip of a Tyrannosaurus tooth.

Skeleton “Vinnie”

 

FORSTER, 1996

Locality: Western Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

UCMP 113697: Skull (female).

 

GALLAGHER, HATCHER & MORRIS, 2014

Locality: Babyback Triceratops Quarry, within the Trubo Ranch USGS Quadrangle, Township 21 North, Range 36 East, Section 35, 47.53767N, 107.05383W, south of Fort PEck Lake and due east of teh suoutehrnmost drainage of Hell Creek, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

GCM 126: Fragmentary skull and Fragmentary skeleton.

 

GARSTKA & BURNHAM, 1997

Locality: SW ¼ section, 19 T13N, R105W, North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

WFQ:9309 (Willy): Skull and nearly complete skeleton.

 

Locality: NE ¼ section, 7 T132N, R105W, North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

WFQ:WRG94.014 (Raymond): Disarticulated skull and fragmentary skeleton.

 

GLUT, 2006

Locality: Wyoming.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

TCM 2001.93.1: Skull.

Note: Nicknamed "Kelsey".

 

Locality: Lennar Homes Subdivision, near Denver, Denver County, Colorado.

Horizon: Denver Formation.

Biostratigraphy:

Age: Lancian age, Late Maastrichtian Stage, Upper Senonian Subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

DMNH 48617: Fragmentary skull.

GOODWIN, 1998

Locality: UCMP V97006, small badland area located just north of the divide separating the drainages of Snow Creek, to the north and Hell Creek, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

UCMP 154452: Fragmentary skull of a juvenile.

UCMP 136306, 113697: Larger juvenile skulls.

 

GOODWIN & HORNER, 2007

Locality: Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

UCMP 159233: Fragmentary left postorbital horn of a juvenile.

UCMP 158441: Right baby postorbital horn.

UCMP 399749: Right baby postorbital horn.

UCMP 400001: An isolated juvenile epinasal.

Note: The above were found as surface "float".

MOR 2572: Right juvenile squamosal.

 

Locality: UCMP Locality V83226 (Harley's Puzzle), Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

UCMP 128562: Left surangular, 4 epiparietals and episquamosals, epinasal, posterior left dentary and left postorbital of a juvenile.

 

HAPP & MORROW, 1997, HAPP & MORROW, 2000, HAPP, 2003, 2007

Locality: Near Jordan, Section 2, Townships 20 North, Range 37E, 47°31'40"N, 106°58'29"W, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

SUP 9713: Skull and fragmentary skeleton of a juvenile.
Note: Skin impressions and teeth marks from crocodilians and small theropods.
Note: HAPP & MORROW, 2000, state that there is soft tissue impressions in the skull.
Note: HAPP 2003, 2008 notes that there are pathologies on the skull, the left horn is missing more than 1/3rd its length, toothmarks, 3 parallel marks on the left squamosal.

 

HATCHER, 2007

Locality: Privately owned lands within the Hell Hollow and Trumbo Ranch USGS Quadrangles of Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

GCM 105, 106, 120 and others left in situ.

 

HORNER & GOODMAN, 2008

Locality: Garifield and McCone Counties, Eastern Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

MOR 1100 (SG-5): Juvenile skull.

MOR 1120 (Getaway Trike): Subadult skull.

MOR 2574 (Quitin' Time): Subadult skull.

MOR 2570 (Scavenged skull): Adult skull.

UCMP 137263: Subadult skull.

UCMP 13766: Subadult skull.

UCMP 144297 (Bay Stud Coulee): Adult skull.

UCMP 174838 (Coyote Basin): Adult skull.

 

/SCANNELA & FOWLER, 2014

Locality: HC-376, Baker Trike, northeastern Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

MOR 1604: Articulated skull and syncervical.

 

Locality: HC-385, Haxby Trike, northeastern Montana.

Horizon: Upper unit, Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

MOR 1625: Partial articualted skull including premax/nasal horn/rostrum/partial postorbital horn/ squamosal/parietal.

 

MORELES & CAMPBELL, 2006

Number: Not given: Fragmentary skull of a subadult.

 

LAMBE, 1914

Locality: Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

NMC 58: Skull lacking frill.

 

LARSON, LARSON, OTT & BAKKER, 2007

Locality: Zerbst Ranch, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

BHI 6273: Fragmentary skull and skeleton.
Note: Has skin impressions and is the best 'mummified' ceratopsian specimen.

LULL, 1933

Locality: Chalk Butte region, between Powderville and Ekalkaka, Montana.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

FMNH 12003: Skull and various skeletal parts and several pairs of horn cores (Male)

 

Locality: Short Pine Hills, Harding County, northeast quarter of Sec. 35, tp 17N, R1E, South Dakota.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

South Dakota State School of Mines, P 271: Skull.

From near the locality another skull.

 

OSTROM & WELLNHOFFER, 1986

Locality: Lance Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

USNM 5738, YPM 1836, 1838:

 

Locality: Buck Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

USNM 2124, 7239:

 

Locality: Dogie Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

YPM 1837:

USNM 5740: Section skull showing braincase.

RICH, 1996

Locality: Lance Creek Area, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Number: Not given: Skull.

 

RUSSELL & MANABE, 2002, FUJIWARA, 2009

Locality: Bowman County, North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

NSM PV20379: Nearly complete skull and skeleton. Nicknamed “Raymond".

SPENCER, TURNER & CHADWICK, 2001

Locality: Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Number: Not given: Teeth.

 

TRIEBOLD & RUSSELL, 1995

Locality: “Sandy Quarry”, near Buffalo, South Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Number: Not given:

 

= Triceratops prorsus referred specimen FORSTER, 1996, ERICKSON & PICKETT, 1987/ERICKSON, 1966

Locality: Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

SMM P62/1/1: Partial skull and skeleton. (female).
Note: Skull shows a partially healded-puncture wound just below the left eye, may be from another Triceratops. (ROBERT J. MEYERSON pers comm).

ERICKSON, 2017

Locality: Triceratops Quarry, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

SMM P93.16/1, SMM P 2014.3.1C: Braincase.

 

Locality: Locality 11, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

SMM: Skull.

 

Locality: Locality 19, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

SMM: Skull.

 

Locality: Locality 24, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

SMM: Skull and skeleton.

= Polyonax mortuarius COPE, 1874 (nomen dubium)
Etymology: Greek, mortuarius, "belong to the dead."
= Agathaumas mortuarius (COPE, 1874) HAY, 1901 (nomen dubium)

Holotype: AMNH 3950

Locality: Unknown, Colorado.

Horizon: Laramie Formation.

Biostratigraphy:

Age: Lancian Age, upper Maastrichtian Stage, uppermost Senonian Subepoch, Upper Upper Gulf Epoch, Late Cretaceous.

Material: 3 dorsal vertebrae and fragments of horncores.

 

= Triceratops flabellatus MARSH, 1889
Etymology: Latin, flabellatus, "fan-like."
= Sterrholophus flabellatus MARSH, 1889
= Trioceratops flabellatus KEYES, 1894 (sic)

Holotype: YPM 1821

Locality: It laid in a bed of arenaceous shale, at the summit and at the extreme western point of a high and rocky ridge about half a mile in length, running westward from the main divide between Buck Creek and Lance Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Note: Perhaps somewhat above that of any of the other members of the ceratopsidae, other than T. sulcatus.

Material: Skull and dentary, femur, ilium, ischium, scapula and a few vertebrae of a juvenile male.

Referred material:

Top incorrect illustration from Marsh; bottom corrected skull from Lull, 1934.

= Triceratops cf. flabellatus BREITHAUPT, 1985

Locality: Wyoming.

Horizon: Lower Evanston Formation.

Biostratigraphy:

Age: Lancian age, uppermost Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Number: Not given:

 

= Triceratops serratus MARSH, 1890
Etymology: Latin, serratus, "serrated."

Holotype: YPM 1823

Locality: Lightning Creek, Niobrara County, Wyoming.

Note: According to HATCHER, MARSH & LULL is as follows. ‘the exact locality was on the north side of the middle fork and about 3 miles above the mouth of the draw of Dry Creek, which empties into Lance Creek form the west, immediately below the U-L cattle ranch, then long abandoned, but now occupied as a sheep ranch by r. Jacob Mills.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Skull and jaws.
Note: Paleopathology, the right mandibular ramus is somewhat pathologic (LULL, 1933).

Referred material:

GILMORE, 1919

Locality: Buck Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

USNM 2416: Fragmentary skull.

 

LULL, 1903

Locality: In the wall of Hell Creek Canon, Sieber ranch, some 25 miles form the Missouri River, and 35 miles northwest of Miles City, Montana.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

AMNH 970: The skull lacks only the distal portions of the postfrontal horn cores, the nasals and their horn core, and a portion of the premaxillary bones, fragmentary dentary, forelimbs.

Note: Modeled forelimb for the composite skeleton of the Triceratops elatus (skull is Triceratops sternbergii, FORSTER Thesis, nomen nudum) at the American Museum of Natural History.

Note: More than likely this is actually a Torosaurus skull.

 

= Triceratops sulcatus MARSH, 1890 (nomen dubium)
Etymology: Latin, sulcatus, past participle of sulcare, "to make furrowed." 

Holotype: USNM 4276

Locality: Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Note: Perhaps somewhat above that of any of the other members of the ceratopsidae, other than T. flabellatus.

Material: Poorly persevered skull, jaws, several vertebrae and some limb material.
Note: Paleopathology, an orbital horn core evidently suffered a fracture in life with the distal portion being subsequently lost (HATCHER, MARSH & LULL, 1908, reprinted 1980)

Referred material:

Locality: Buck Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

USNM 4286, 1203, 1206-1210: Fragmentary skulls.

DERSTER, 1994

Number: Not given: An articulated skeleton missing the skull in situ.

= Triceratops elatus MARSH, 1891
Etymology: Latin, elatus, "lofty, proud, high."
= Trisceratops elatus KEYES, 1894 (sic)

Holotype: USNM 1201

Locality: Lance Creek, Niobrara County, Wyoming.
Note: According to HATCHER, MARSH & LULL, 1907, “It lay on the gently sloping hillside, about a quarter of a mile form the creek and directly opposite the mouth of Lightning Creek.”

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Skull (male).
Note: Paleopathology, left squamosal has a perforaton (TANKE & ROTHSCHILD, 2002).

Plesiotype: USNM 4805

Locality: About 10 feet from the type.

Material: Right dentary with the surangular and coronoid, a portion of the left surangular, the occipital condyle, nasal horn core, an imperfect pterygoid, several epoccipitals, and some other portions of the skull and skeleton not now accessible Male).

Referred material:

GILMORE, 1919

Locality: Near Buck Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

USNM 4708: Postorbital horn cores, right-horn core was broken off during life.

 

GILMORE, 1920

Locality: Lance Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

USNM 2100: Skull (Male).

= Triceratops? elatus

Locality: Cow Creek, Fergus County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

YPM 1829:

 

LULL, 1933

Locality: Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

USNM 5741: Skull.

 

= Claorhynchus trihedrus COPE, 1892 (nomen dubium)
Etymology: Latin, tri, "three" and Latin, hedrus, "sided."

Holotype: AMNH 3978

Locality: Judith River, Fergus County, Montana.

Horizon: Judith River Formation.

Biostratigraphy:

Age: Judithian age, Campanian Stage, Senonian subepoch, Upper Gulf epoch, Late Cretaceous.

Material: Premaxillary tip and predentary.

 

= Triceratops obtusus MARSH, 1898
Etymology: Latin, obtusus, "blunt."

Holotype: USNM 4720

Locality: 1 mile east of Lance Creek and 2 miles southeast of the U-L Ranch, Converse [Niobrara] County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Nearly complete skull and vertebra (Male).

Nasals.

 

= Triceratops calicornis MARSH, 1898
Etymology: Greek, cali, "beautiful" and Latin, corneus, "horn, made of horn."
= Triceratops californis WOLCOTT, 1900 (sic)

Holotype: MNHN 1912.20 (was USNM 4928)

Locality: Found about 1 mile nearly due south of the locality which yielded the skeleton referred by marsh to Triceratops prorsus USNM 4842, Lance Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Skull lacking some parts of the frill, lower jaws, 2 cervical vertebrae, portions of atlas and other cervicals, 10 dorsal vertebrae, portions of the other dorsals, 5 cervical ribs, 2 thoracic ribs (many of the others), both pubes, both ilia (poorly preserved), sacrum (poorly preserved), and many ossified vertebrae (Male).

= Triceratops ingens LULL, 1915 (nomen dubium)
Etymology: Latin, ingens, "enormous, massive."

Holotype: YPM 1828

Locality: Dogie Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Unprepared cranial and post-cranial material.

 

= Triceratops maximus BROWN, 1933
Etymology: Latin, maximus, "greatest."

Holotype: AMNH 5040

Locality: Rock Creek, 20 miles south of Lismas, Garfield County, Montana. (according to LULL, 1933: 20 miles south of Lismas, along the canyon of Hell Creek, about 30 miles above Milk River, in the northern part of Dawson County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: 8 free vertebrae and 2 cervical ribs.

_____________________________________________________________________________________

Species: prorsus MARSH, 1890
Etymology: Latin, prorsus, "straightforward."
= Agathaumas prorsus (MARSH, 1890) LYDEKKER, 1893

Holotype: YPM 1822

Locality: Lightning Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Skull and jaws and 6 cervicals (female).

Note: When discovered, the skull lay a few feet above the bottom of the canyon and at a slightly lower horizon that the type of T. serratus.

Note: According to HATCHER, MARSH & LULL is as follows. ‘the exact locality was on the north side of the middle fork and about 3 miles above the mouth of the draw of Dry Creek, which empties into Lance Creek form the west, immediately below the U-L cattle ranch, then long abandoned, but now occupied as a sheep ranch by r. Jacob Mills.

Referred material:

ANONYMOUS, 1911/1912

Locality: Near Schneider Creek, Niobrara County, Wyoming.

Horizon: Laramie Formation.

Biostratigraphy:

Age: Lancian Age, upper Maastrichtian Stage, uppermost Senonian Subepoch, Upper Upper Gulf Epoch, Late Cretaceous.

Material:

BMNH: Nearly complete skull lacking the middle of the occipital crest, the left horn-core, and the left quadrate. (Nearly 6 1/2 feet long)

BMNH: Two other fragmentary skulls are at the ?Senckenberg Museum.

 

FORSTER, 1996/MOLNAR, 1978?

Locality: On the Lester D. Engdahl Ranch (not, as originally noted, the F. S. McKeever Ranch), S34, T21N, R37E, near Jordan, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

LACM 7207: Fragmentary skull.
Note: Found near the skull of Stygivenator molnari.

 

FOSTER, 1996

Locality: Western Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

SDSM 2760: Skull.

 

GILMORE, 1906

Locality: Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

USNM 4842: Nearly complete skull and fragmentary skeleton.

 

HATCHER, MARSH & LULL, 1907

Locality:

Horizon:

Biostratigraphy:

Age:

Material:

YPM 2082: Left tibia and coossified astragalus.

 

Locality:

Horizon:

Biostratigraphy:

Age:

Material:

USNM 2100: Skull missing snout.
Note: This is mounted on the skeleton at the United States National Museum.

HOLLAND, 1997

Locality: West of the road, north of Pretty Butte, some 29 km (18mi) northwest of Marmarth, north of Cannonball Creek on land leased by Lyle Tennant from the U.S. Forest Service, SE ¼, NE ¼, NE ¼, NW ¼, sec. 32, T135N, R106W, Badland Draw Quadrangle Montana-North Dakota, 7.5 minute series, 1:24,000, Slope County, North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

University of North Dakota Paleontology Collections, UND 3000: Fragmentary skull.

 

LULL, 1933

Locality: Hell Creek, along the canyon of Hell Creek, about 30 miles above the mouth of Milk River, in the northern part of Dawson County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Amherst College Collection: Skull with recurved nasal horn.

 

LUPTON, GABRIEL & WEST, 1980

Locality: Chris's Bone bed, McCone County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Number: Not given: Vertebrae, iliac blade, phalanges, fragment of maxillary bone with teeth and seven isolated teeth.

 

OSTROM & WELLNHOFFER, 1986

Locality: Buck Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

USNM 1205:

 

STENERSON & O’CONNER, 1994

Locality: Northwestern South Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Number: Not given: Teeth, frill, horns and vertebrae.

 

STERNBERG, 1924

Locality: Badlands in Sec. 15, T1, R5W, 3rd principal meridian, Rocky Creek, Saskatchewan Province, Canada.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Number: Not given:

 

STERNBERG, 1949/TOKARYK, 1986

Locality: Morgan Creek, east branch of Rocky Creek, Saskatchewan Province, Canada.

Horizon: Frenchman Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

GSC 8598: Anterior part of the nasals and the horncore.

 

Locality: East of Eastend, north side of Frenchman River, Saskatchewan Province, Canada.

Horizon: Frenchman Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

GSC 8864: Anterior part of nasals and the horncore.

 

Locality: Southeast of Eastman, Frenchman River Valley, Saskatchewan Province, Canada.

Horizon: Frenchman Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

EMP14.1: Skull cast of ROM No. 1434 (Skull and incomplete skeleton)

 

TOKARYK, 1985

Locality: Locality 72F08-0003, Triceratops Quarry, 22 mi South of Shaunavon, LSD 7, S5, T5, R18W 3rd Meridian, Frenchman River Valley, Saskatchewan Province, Canada.

Horizon: Frenchman Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

SMNH P1163.4: Nearly complete skull.
Note: Paleopathology, serious healing transverse fracture on the parietal bar also possible pathologic frill (TANKE & ROTHSCHILD, 2002, TANKE, FARKE & GILBERT, 2009).

Number: Not given: Several other bones.

 

TOKARYK, 1997

Locality: Frenchman Valley, Saskatchewan Province, Canada.

Horizon: Frenchman Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

SMNH P.2525.1: Partial skull and skeleton.

Number: Not given: Several partial skulls and skeletons that still need to be collected.

 

Locality: Frenchman River Valley, Saskatchewan Province, Canada.

Horizon: Frenchman Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

EM P15.1: Fragmentary skull.

 

= Triceratops brevicornus HATCHER, 1905
Etymology: Latin, brevis, "short" and Latin, cornus, "horn."

Holotype: YPM 1834 (now at Bayerische Stattssammlung fur Palaontologie und Historische Geologie, BSP 1964 I 458) (female)

Locality: About 3 miles above the mouth of Lightning Creek, and about 1 1/2 miles south of the stream, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Skull, dentary, co-ossified atlas/axis, cervicals 3-4 fragmentary, 5-8, and dorsal vertebrae1-7, 8-14 fragmentary, 1 caudal vertebra, fragmentary ribs, right fragmentary pubis.

Referred material:

Locality: Hell Creek, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

CM 1219: Fragmentary skull.

CM: Another fragmentary skull.

 

FORSTER, 1996

Locality: Western Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

CM 1221: Skull (female).

 

OSTROM & WELLNHOFFER, 1986

Locality: Lightning Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

YPM 183:

 

= Triceratops cf. brevicornis SCHUYF, 1969

Locality: Lightning Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

Mineralogisch-Geologisch Museum, number?: 9 m long skull.

_____________________________________________________________________________________

Note: Jack Horner (pers. comm…) has a Triceratops bone bed in eastern Montana.
_____________________________________________________________________________________

SCANNELLA & HORNER, 2010

No locality or horizon locality given.

MOR 004: Articulated skull.

MOR 335: Parietal.

MOR 539: Partial skull.

MOR 699: Disarticulated skull.

MOR 965: Partial skull.

MOR 981: Articulated skull.

MOR 989: Nasal norn, rostral.

MOR 1098: Postorbital horn core.

MOR 1110: Disarticulated skull.

MOR 1120: Disarticulated skull.

MOR 1122: Articulated skull.

MOR 1199: Disarticualted skull.

MOR 1604: Articulated skull.

MOR 1625: Partial skull.

MOR 2927: Squamosal, postorbital horn core.

MOR 2928: Squamosal, dentary.

MOR 2929: Squamosal.

MOR 2937: Maxilla.

MOR 2938: Partial disarticulated skull.

MOR 2942: Squamosal.

MOR 2945: Dentary.

MOR 2946: Partial, squamosal.

MOR 2950: Partial skull.

MOR 2951: Disarticulated skull.

MOR 2952: Partial skull.

MOR 2436: Partial disarticualted skull.

MOR 2551: Partial skull.

MOR 2552: Partial skull.

MOR 2569: Disarticulated skull.

MOR 2570: Partial skull.

MOR 2572: Squamosal.

MOR 2574: Disarticulated skull.

MOR 2576: Postorbital horn core.

MOR 2589: Postorbital horn core.

MOR 2590: Premaxilla.

MOR 2702: Partial skull.

MOR 2923: Articulated skull.

MOR 2924: Disarticulated skull.

MOR 2958: Postorbital horn core.

MOR 2959: Partial skull.

MOR 2969: Parietal.

MOR 2970: Squamosal.

MOR 2971: Partial disarticulated skull.

MOR 2972: Partial skull.

MOR 2975: Partial skull.

MOR 2979: Partial skull.

MOR 2980: Squamosal.

MOR 2982: Partial disarticulated skull.

MOR 2984: Partial skull.

Locality: HC-444, Mark's Trike II, northeastern Montana.

Horizon: Upper unit, Hell Creek Formation.

Biostratigraphy:

Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

MOR 2597: Partial skull.