Genus: Protolambda OSBORN, 1898
Etymology: Greek, protos, "first" + Lambda.
= Aletridelphys DAVIS, 2007
Etymology: Greek, aletris, meaing a female slave who grinds corn; in reference to the broad molars of referred species, and Greek, delphys, 'womb'; a common suffix for marsupials.

Species: hatcheri OSBORN, 1898
Etymology: In honor of John Bell Hatcher.
= Pediomys hatcheri (OSBORN, 1898) CLEMENS, 1961

Lectotype: AMNH 2202

Locality: Lance Creek Area, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material: Fragmentary right maxilla with UM3.

Syntype: AMNH 2203: UM2.

Referred material:

ARCHIBALD, 1982

Locality: V73087, Flat Creek 5, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

UCMP 117635: Fragment of 1 UMx.

 

Locality: V72208, Lead Slug Hill, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

UCMP 110630: Fragment of UM2 or UM3.

 

 

Locality: V73076, Engdahl Anthills 2, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

UCMP 108979: LM4.

 

CLEMENS, 1961

Locality: Dragon Canyon on the eastern side of the Wasatch Plateau, Utah.

Horizon: North Horn Formation.

Biostratigraphy:

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

Material:

UCMP 55640: Maxilla fragment with upper molar.

 

CLEMENS, 1966

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:

UCMP 50294: Fragment of maxilla with alveolus of UC, roots of UP1 and UP2-3, UM1.

UCMP 51400: Fragment of maxilla with UM1-2.

UCMP 46881: Fragment of right dentary with LM2-LM4, inclusive.

AMNH 58848: Fragment of right dentary with LP3-LM3, inclusive.

Numbers: Not given: plus 24 isolated teeth.

 

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:

UCMP 48157: Fragment of maxilla with UDP3, and UM1.

AMNH 58745: Fragment of maxilla with UP3 and UM1.

AMNH 58763: Fragment of maxilla with UM1-2.

AMNH 57982: Fragment of maxilla with UM1-3.

KU 12955: Fragment of maxilla with UM3-4.

AMNH 57983: Fragment of maxilla with UM2-3.

AMNH 58793: Fragment of right mandible with LP2 and LP3.

Numbers: Not given: plus 41 isolated teeth.

 

Locality: UCMP V-5619, Wyoming.

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

Localities: UCMP V-5616, Altman Blowout, this large blowout, site of the UCMP field-party camps form 1956 to 1960, is just east of the crest of the divide separating Lance Creek and Hancock Creek and 100 yards east of a dirt road. Fossils were found in anthills, talus, and sandstone exposed in the blowout, which is in the NE 1/4, Sec. 9, T37N, R64W, Eastern Wyoming.7

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, 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, 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.

 

cf. P. hatcheri FOX, 1979

Locality: Near Irvine, Cypress 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,

Material:

UA 14816: Lower molar.

 

HUNTER, HARTMAN & KRAUSE, 1997

Locality: Muddy Tork Locality, Makoshika State Park, Williston Basin, Dawson County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

MOR 803: Right maxillary fragment with M2.

 

Locality: Vashus Locality, Makoshika State Park, Williston Basin, Dawson County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

V-1: Left dentary with M3, M4.

 

LILLEGRAVEN, 1969

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

UA 3690: Fragmentary mandible with roots of LP1-3, LM1-4.

UA 3690: LM3.

 

WHITMORE, 1988

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 12372: Left M2.

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Species: florencae (CLEMENS, 1966) emend DAVIS, 2006
Etymology:
= Pediomys florencae CLEMENS, 1966

Holotype: UCMP 51440

Locality: UCMP V5820, Kent 484, on the surface near the top of the east side of a small draw on the south side of the prominent hill northeast of the J. Krejci ranch house, Wyoming.

Horizon: Lance Formation.

Biostratigraphy:

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

Material: Fragmentary left maxilla with UM2-3.

Referred material:

AMNH 2201:

 

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:

Numbers: Not given: 39 fragments of maxilla each containing but 1 tooth or isolated teeth.

 

 

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:

AMNH 59478: Edentulos fragment of maxilla with alveoli of UM2-4.

KU 12953: Fragment of left dentary with LM2 and alveoli of LM3 and LM4.

Numbers: Not given: plus 38 fragments of maxillae each containing but a single tooth or isolated teeth.

 

Localities: UCMP V-5622, V-5820, Wyoming.

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

Localities: UCMP V-5616, Altman Blowout, this large blowout, site of the UCMP field-party camps form 1956 to 1960, is just east of the crest of the divide separating Lance Creek and Hancock Creek and 100 yards east of a dirt road. Fossils were found in anthills, talus, and sandstone exposed in the blowout, which is in the NE 1/4, Sec. 9, T37N, R64W, Eastern Wyoming.7

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, 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, 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.

 

ARCHIBALD, 1982

Locality: V72213, V73087, V74106, V74116, V75178, and V76161, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

Numbers: Not given: 10 teeth and tooth fragments.

 

Locality: Flat Creek local fauna, Garfield County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

UCMP 110541: Edentulous dentary.

 

HUNTER & ARCHIBALD, 2002

Locality: PTRM locality V89004, Miller Butte Locality, North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

PTRM 605: Right m2.

 

= “Pediomys” sp. cf. “P”. florencae HUNTER & PEARSON, 1996

Pioneer Trails Regional Museum, Bowman, North Dakota, PTRM-1255

Locality: PTRM-V92067, Little Missouri badlands on public (county) land in the NE 1/4, NW 1/4, SE 1/4, SW 1/4, Section 27, T131N, R105W, Cedar Hills Quadrangle, Bowman County, North Dakota.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material: Right dentary with roots of p1, and p2, p3, m2 talonid, m3.

 

 

HUNTER, HARTMAN & KRAUSE, 1997

Locality: Muddy Tork Locality, Makoshika State Park, Williston Basin, Dawson County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

MOR 800: Left dentary fragment with M3, M4 alveoli.

MOR 876: Left dentary with m3, taloinid of m2, roots of M4.

 

 

Locality: Specific locality unknown, Makoshika State Park, Williston Basin, Dawson County, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

MOR 883: Right maxillary fragment with M2, M3, fragment of M4 and roots of M1.

 

LOFGREN, 1995

Locality: UCMP V85092, K-Mark, Bug Creek anthill, McGuire Creek, Montana.

Horizon: Hell Creek Formation.

Biostratigraphy:

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

Material:

UCMP 134792: Right edentulous dentary fragment.

 

= Pediomys cf. P. florencae RUSSELL, 1987

Locality: Henry Farm Locality, 1s, 8, sec. 5, tp 39, rge 22, W4thM, north side of the Red Deer River valley, 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:

ROM 25352: Talonid of a right M1 or M2.

WILSON, DECHENSE & ANDERSON, 2010

Locality: Ingrid’s Jaw, DMNH loc. 3322 (=UWBM loc. C1098) is an irregular, weathered isolated outcrop of ~30 m2 immediately south of Weld County Road 122, Pawnee National Grasslands, Cheyenne basin, Weld County, Colorado.

Horizon: Upper Laramie Formation.

Biostratigraphy:

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

Material:

DMNH 52228: Lingual fragment of a left M2.

Locality: The Natural Fort, UCM loc. 78193, is located among a large outcrop of ~0.4 km2 and up to 12 m in relief that lies immediately east of Interstate 25 near northbound exit 293, where there was once a rest area, Pawnee National Grasslands, Cheyenne basin, Weld County, Colorado.

Horizon: Upper Laramie Formation.

Biostratigraphy:

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

Material:

UCM 40589: Left dentary fragment with p3.

 

 

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Species: clemensi (SAHNI, 1972) emend DAVIS, 2006
Etymolgy: In honor of Dr. Clemens, for his work in Mesozoic mammals.
= Pediomys clemensi SAHNI, 1972

Holotype: AMNH 77373

Locality: Clambank Hollow, Chouteau County, Montana.

Horizon: Judith River Formation.

Biostratigraphy:

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

Material: UM2 or UM3.

Referred material:

AMNH 77374: UM.

AMNH 77377: UM.

 

ARCHIBALD, 1987

Locality: Piceance Creek Basin, North West Colorado.

Horizon: Williams Fork Formation.

Biostratigraphy:

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

Material:

Number: Not given:

 

FOX, 1979

Locality: Alberta, Canada.

Horizon: Judith River Formation.

Biostratigraphy:

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

Material:

UA 14812: Right maxillary fragment having UM1-3 (UM2 incomplete).

UA 4349: Left maxillary fragment having UM2-3.

UA 14811: Right dentary fragment having LM1-4.

UA 14810: Left dentary fragment having LP1-3, LM2-4, (LM4 incomplete).

 

 

KOSTER, CURRIE, EBERTH, BRINKMAN, JOHNSTON & BRAMAN, 1987

Locality: 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:

Number: Not given:

 

 

MONTELLANO, 1992

Locality: UCMP V-81234, Put’s Plunder, Kennedy Coulee, Sections 10, 19, 29, and 30, Township 37N, Range 9E, and in Sections 23, and 24, Township 37N, range 8E, approximately 40 km north of Rudyard, Hill County, Montana.

Horizon: Judith River Formation.

Biostratigraphy:

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

Material:

UCMP 131338: M1.

UCMP 131329, 131339, 131340: m2-3.

 

Locality: UCMP V-78097, French 3 Hill, Havre Badlands, Hill County, Montana.

Horizon: Judith River Formation.

Biostratigraphy:

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

Material:

UCMP 122151: m2-3.

 

Locality: UCMP V-78098, Garbani 1, Havre Badlands, Hill County, Montana.

Horizon: Judith River Formation.

Biostratigraphy:

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

Material:

UCMP 122148: M1.

UCMP 131330: M2-3?

UCMP 130558, 122178: 2 m2-3.

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Species: mcgilli KELLY, 2014
Etymology: In honor of Lewis McGill for his considerate support of this study adn allowing access to the LLJS Quarry on his ranch propteryt. In addition, Lewis donated many of ht especimens reported herein.

Holotype: LACM 15792

Locality: Lane's Little Jaw Site Quarry (= locaity LACM 7942): Powder River County, Montana.

Horizon: Hell Creek Formation?

Biostratigraphy:

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

Material: Partial right dentary wiht m2-3.

Referred material:

LACM 157293: Partial left denatry with m3.