Genus: Vagaceratops SAMPSON, LOEWEN, FARKE, ROBERTS, FORSTER, SMITH & TITUS, 2010
Etymology: Latin, vagas, "wanderer" and Greek, ceratops, "horned face"; in reference to the occurrence of this clade in the north (Alberta) and south (Utah) of Laramidia during the late Campanian.

Species: irviensis (HOLMES, FORSTER, RYAN & SHEPHERD, 2001) SAMPSON, LOEWEN, FARKE, ROBERTS, FORSTER, SMITH & TITUS, 2010 (Type)
= Chasmosaurus irvinensis HOLMES, FORSTER, RYAN & SHEPHERD, 2001
Etymology: In reference to Irvine, Alberta, Canada, near where the type was found.
= Nova HOLMES, SHEPHERD & FORSTER, 1999

Holotype: CMN (NMC) 41357

Locality: 4.2 km southwest of Irvine, NE ¼ section 23, T11, R3, west of the 4th meridian, Cypress County, Alberta Province, Canada.

Horizon: Upper Dinosaur Park Formation, upper Judith River Group.

Biostratigraphy:

Age: Judithian age, Middle Campanian Stage, middle Senonian subepoch, upper Gulf Epoch, Late Cretaceous.

Material: Fragmentary skull and fragmentary skeleton.
Note: Paleopathology, orbital horn core resorption pits, an extra fontanelle affecting the right squamosal. Also right first metacarpus and proximal pollical phalanx is pathologic (REGA & HOLMES, 2006)

Referred material:

Locality: Quarry 184, 4.8 km NW of Iddesleight, Cypress County, Alberta Province, Canada.

Horizon: Upper Dinosaur Park Formation, upper Judith River Group.

Biostratigraphy:

Age: Judithian age, Middle Campanian Stage, middle Senonian subepoch, upper Gulf Epoch, Late Cretaceous.

Material:

RTMP 87.45.1: Dorsoventrally crushed skull lacking mandible, most of the posterior parietal bar, most of the right squamosal, and distal tip of the right jugal.

 

Locality: Near the village of Onefour, Cypress County, Southeastern Alberta Province, Canada.

Horizon: Upper Dinosaur Park Formation, upper Judith River Group.

Biostratigraphy:

Age: Judithian age, Middle Campanian Stage, middle Senonian subepoch, upper Gulf Epoch, Late Cretaceous.

Material:

RTMP 98.102.8: Fragmentary skull with nearly complete posterior parietal bar.

RTMP 98.102.1: Hundreds of skull fragments.

RTMP 98.102.8: Miscellaneous associated frill fragments.

= Chasmosaurus belli (referred) LULL, 1933

Locality: Dinosaur Provincial Park, 1 miles below Steveville, Tp 21, R12, on the left bank of the Red Deer River, Newell County, Alberta Province, Canada.

Horizon: Dinosaur Park Formation, upper Judith River Group.

Biostratigraphy:

Age: Judithian age, Middle Campanian Stage, middle Senonian subepoch, upper Gulf Epoch, Late Cretaceous.

Material:

AMNH 5402: Skull, right dentary, splenial, predentary, cervical, dorsal, caudal vertebrae, sacrum, radius, ribs, femur, tibia and metapodials.

 

= Chasmosaurus belli (referred) OSTROM, 1966

Locality: Quarry 110, Dinosaur Provincial Park, South side of the west branch of Little Sandhill Creek, 60 feet below the overlying Pierre shales, Dinosaur Provincial Park, Red Deer River, Newell County, Alberta Province, Canada.

Horizon: Dinosaur Park Formation, upper Judith River Group.

Biostratigraphy:

Age: Judithian age, Middle Campanian Stage, middle Senonian subepoch, upper Gulf Epoch, Late Cretaceous.

Material:

YPM 2016: Skull.

 

STERNBERG, 1925

Locality: Dinosaur Provincial Park, 2 1/2 miles southeast of the mouth of Little Sand Hill Creek about 160 feet above the Red Deer River, Dinosaur Provincial Park, Newell County, Alberta Province, Canada.

Horizon: Dinosaur Park Formation, upper Judith River Group.

Biostratigraphy:

Age: Judithian age, Middle Campanian Stage, middle Senonian subepoch, upper Gulf Epoch, Late Cretaceous.

Material:

CM 2280: Skull, jaws, column complete and articulated to the 4th sacral, complete series of ribs except 5 cervicals, and d2 dorsals, and parts of some others, both scapulae, right coracoid, both sternal bones, anterior portion of right ilium, anterior 2/3rds of left ilium, both pubes, both humeri and the proximal portion of the left femur.