Species: montana GILMORE, 1911
Etymology: In reference to Montana, where the specimen was discovered.

Holotype: AMNH-DVP 5032

Locality: 25 miles southeast at Lismas, Dawson County, Montana.

Horizon: Lance Formation.

Biostratigraphy:

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

Material: Skull missing the posterior portion from the orbits.

Referred material:

BREITHAUPT, 1985

Locality: Wyoming.

Horizon: "Mesaverde" Formation.

Biostratigraphy:

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

Material:

Number: Not given:

 

CARPENTER & LINDSEY, 1980

Locality: Sec. 25, T20N, R21W, Carson County, South Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

DMNH 471: Left dentary.

 

Localities: UCMP Localities V-5002, V-5004, V-51616-V-51619, V-5622-V5624, V-5710, V-5713, V-5715, V-5820, V-5875, V-5919-V5920, V-5922, Eastern Wyoming.

Locality: UCMP V-5003, S 1/2, Sec. 20, T37N, R64W, Lance Creek, Powder River Basin, Niobrara County, Wyoming.

Locality: UCMP V-5815, Hatcher Number 2, western side of a cross-stratified sandstone erosional remnant near the center of a large blowout on the crest of a ridge, the distance form the nearest point on the road, approximately 150 yards south of the quarry, to the Johnson ranch is 0.4 miles, Niobrara County (Formerly Converse County), Eastern Wyoming.

Locality: UCMP V-5817, False Disciple Point, cross-stratified sandstone and sandy shales cropping out on the top of the northern end of a long, northwestward-trending ridge that extends from the crest of the divide between the Hancock and Lance Creek drainages, Niobrara County (Formerly Converse County), Wyoming.

Locality: UCMP V-5818: Anthills built around the rim of the only blowout on the south side of a canyon that empties into a tributary of Hancock Creek, Niobrara County (Formerly Converse County), Eastern Wyoming.

Locality: UCMP V-5918, Fish tooth Hill, Anthills and talus found in and around a badland area on the eastern side of a north-trending ridge extending from the crest of the divide between Cow and Dogie Creeks, Niobrara County (Formerly Converse County), Eastern Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

Numbers: Not given: Isolated teeth, doubtless some of the skull fragments, vertebrae, limb bones and scutes referred to Leidyosuchus (ESTES 1964) Belong here.

 

ESTES, 1964

Locality: Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

Numbers: Not given: Teeth.

 

ESTES & BERBERIAN, 1970

Locality: Bug Creek Anthills locality, McCone County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

MCZ 3650: Teeth, scutes, fragmentary limb, vertebral and skull bones.

 

BREITHAUPT, 1982

Locality: UW Locality V-79032, Rock Springs Uplift, Sweetwater County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

UW 14081, 14082: Teeth.

 

BYRANT, 1990

Locality: Northeastern Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

UCMP 131575: Tooth and dorsal scute.

UCMP 131576, 131577: Teeth.

 

CARPENTER, 1979

Locality: Crow Creek, Weld County, Colorado.

Horizon: Laramie Formation.

Biostratigraphy:

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

Material:

UCM 38802, 38745, 38831: Teeth.

 

HOLROYD & HUTCHINSON, 2002

Locality: V 86049, western North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

177996-177997:

 

 

Locality: V 86071, western North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

172099:

 

 

Locality: V 86072, western North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

172133:

Locality: V 86095, western North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

172194:

 

Locality: V 86097, western North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

172227:

Locality: V 86099, western North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

177871:

 

Locality: V 86100, western North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

172158:

NORELL, CLARK & HUTCHISON, 1994

Locality: UCMP locality V86049, sec. 14, T124N, R106W, Slope County, North Dakota.

Horizon: Hell Creek Formation, 23.3 m below the contact with the Ludlow Formation,

Biostratigraphy:

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

Material:

UCMP 133901: Skull with articulated mandible, the hyoid skeleton, the vertebral column from atlas to sacrum but posterior part of the series poorly preserved dorsal osteoderms of neck, trunk and proximal part of tail, ventral armor of throat (there appears to have been no belly armor), most of forelegs lacking only the distal ulnae and parts of the right manus, proximal parts of scapula and coracoid, interclavicle, right femur, left femur lacking distal end, proximal fibula and partial right ilium.

 

SULLIVAN & LUCAS, 2001, 2003

Locality: SMP locality 376a Willow Wash (north-central), San Juan Basin, New Mexico.

Horizon: De-na-zin Member, Lower Kirtland Formation.

Biostratigraphy:

Age: Kirtlandian age, Upper Campanian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material:

SMP VP-1312: Incomplete skull and lower jaw.

SMP VP-1264: Incomplete skull roof.

 

TRIEBOLD, 1997

Locality: Sandy Site, Harding 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:

 

WHITMORE, 1988

Locality: SDSM Locality V851, Zerbst Locality, east of the Cheyenne River, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

SDSM 12440: 46 teeth.

 

Locality: SDSM Locality V852, Hanson Locality, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

SDSM 12441: 58 teeth.

 

Locality: SDSM Locality V853, Leonard’s Lizard Site, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

SDSM 12442: 6 teeth.

 

Locality: SDSM Locality V685, Greasewood Creek Locality, northern side of the south fork of the Greasewood Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

SDSM 12710: 5 teeth.

 

WOLBERG, HALL, BELLIS, CHAVEX, ANDERSON, MORO, & GIL 1988

Locality: Fossil Forest locality, near Split Lip Flats, San Juan Basin, San Juan County, New Mexico.

Horizon:

Biostratigraphy:

Age: Late Cretaceous.

Material:

Number: Not given:

 

= Bottosaurus perugosus COPE, 1875 (nomen dubium)
Etymology:
= Brachychampsa perrugosa (COPE, 1875) GILMORE, (sic)

AMNH-DVP 1110

Locality: Red Deer River, Alberta Province, Canada.

Horizon: Judith River Formation, Campanian, Late Cretaceous.

Material:

A left mandibular ramus, from which the posterior ends of the dentary and splenial bones and the articular and coronoid elements are missing.

Occiput.

 

= Brachychampsa? sealeyi WILLIAMSON, 1996
Etymology: In honor of Paul L. Sealey, for discovery of the holotype and for his many contributions to New Mexico Paleontology
= Brachychampsa nova WILLIAMSON & SEALEY, 1995

NMMNH P-25050

Locality: NMMNH Locality -3034, Southeastern San Juan Basin, New Mexico.

Horizon: Allison Member, Menefee Formation.

Biostratigraphy:

Age: Lower Campanian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material: Partial skull and associated partial right mandible, partial ramus of the left mandible, and a nearly complete osteoderm.