Species: cracens ESTES, 1969
Etymology: Greek, cracens, "slender."
Holotype: UCMP 46608
Locality: UCMP V-5620, Lull Quarry, near the head of a tributary of Buck Creek, Powder River Basin, Niobrara County (Formerly Converse County), Wyoming.
Horizon: Lance Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material: Left dentary lacking anterior end, all teeth broken at their tips.
Referred material:
UCMP 49958: Posterior fragment of right maxilla.
UCMP 49957: Posterior fragment of left maxilla.
Locality: UC locality V-5825, Powder River Basin, Eastern Wyoming.
Horizon: Lance Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
UCMP 54263: Dentary fragment.
ESTES, BERBERIAN & MESZOELY, 1969
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 3663: Well-worn fragments of dentaries and maxillae.
GAO & FOX, 1996
Locality: KUA-3, Stettler County, Alberta Province, Canada.
Horizon: Scollard Formation, Uppermost Edmonton Group.
Biostratigraphy:
Age: Lancian Age, uppermost Maastrichtian Stage, uppermost Senonian subepoch, Upper Upper Gulf Epoch, Late Cretaceous.
Material:
UALVP 33388: Fragmentary left dentary.
Locality: UCMP V-5711, Bushy Tailed Blowout, Quarry area includes the floor of a small blowout approximately 10 yards northwest of the highest point on the ridge forming the northeastern side of the blowouts of loc. V-5003, S 1/2, Sec. 20, T37N, R64W, Lance Creek, Powder River Basin, Niobrara County, Wyoming.
Horizon: Lance Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
UALVP 29785, 29786: Fragmentary dentaries.