Genus: Nortedelphys CASE, GOIN & WOODBURNE, 2005
Etymology: Castillian, Norte, in reference to the north, to the earliest and northern occurrence for didelphids; Greek, delphys, "womb" in refernece to opossium marsupials.

Species: magnus CASE, GOIN & WOODBURNE, 2005
Etymology: Latin, magnus, "large" in reference to the larger size of the molars of this species.

Holotype: UA 2846

Locality: KUA-1, SW 1/4, SE 1/4, Sec. 18, T34N, R21W, Alberta Province, Canada.

Horizon: Scollard Formation, Uppermost Edmonton Group. (Scollard member, Paskapoo Formation)

Biostratigraphy:

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

Material: Left maxillary fragment with LM1-M4, and left mandibular ramus with Lp3-m4.

Referred material:

Locality: UCMP V-5619 (Nern-Baker), Powder River Basin, Niobrara County, Eastern Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

UCMP 45601: LM1.

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Species: intermedius CASE, GOIN & WOODBURNE, 2005
Etymology: Intermedius in reference to the intermediate size of its molars compared to the other two species of the genus.

Holotype: UCMP 134776

Locality: UCMP V-87072, McCone County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material: LM3.

Referred material:

UCMP 13265: RM1.

 

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, Upper Senonian subepoch, Upper Upper Gulf epoch, Late Cretaceous.

Material:

UCMP 46994:

UCMP 51385: RM1-2.

UCMP 46139: lm3.

UCMP 47588: lm1.

 

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, Upper Senonian subepoch, Upper Upper Gulf epoch, Late Cretaceous.

Material:

UCMP 54479: RM3.

 

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.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

UCMP 51427: LM1-2.

UCMP 53097: RM2.

 

Locality: Lance Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

UW 497:

 

Locality: Bug Creek Anthills, UCMP Locality V65127, McCone County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

UCR 20885: LM3.

UCMP 137350: rm3.

 

Locality: UCMP V651, Painter Ranch, Harding County, South Dakota.

Horizon: Lower Hell Creek Formation.

Biostratigraphy:

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

Material:

SDSM unnumbered:

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Species: minimus CASE, GOIN & WOODBURNE, 2005
Etymology: In reference to the smaller size of its molars compared to the other two larger species.

Holotype: UCMP 72211

Locality: Bug Creek Anthills, UCMP Locality V65127, McCone County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material: LM3.

Referred material:

UCMP 137351: RM1.

 

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, Upper Senonian subepoch, Upper Upper Gulf epoch, Late Cretaceous.

Material:

UCMP 52715: RM2.

 

Locality: Lance Creek, Niobrara County, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

UW 27031: LM1.