Genus: Leptalestes DAVIS, 2007
Etymology: Greek, leptaleos, "thin to delicate"; in reference to the very small and slender form of the upper molars of the type species, and Greek, lestes, "theif"; a common suffix for Cretaceous mammals.

Species: krejcii (CLEMENS, 1966) DAVIS, 2007
Etymology:
= Pediomys krejcii CLEMENS, 1966

Holotype: UCMP 51390

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: Fragmentary left maxilla with UP3 and UM1-3.

Referred material:

AMNH 58784: Fragment of maxilla with UM1-2.

Numbers: Not given: plus 9 isolated teeth.

 


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 51384: Fragment of maxilla with UM2-3.

UCMP 51331: Fragment of ramus and coronoid process containing LM3 and alveoli of LM2.

AMNH 58842: Fragment of ramus including LP2 to LM4, inclusive, alveoli of LP1.

Numbers: Not given: 14 isolated teeth.

 


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.

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: 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 117623: Fragmentary right dentary with Lp2-1 and LM3.

Numbers: Not given: 3 fragmentary upper molars, 1 DUP3, and 1 LM4.

 

 

Locality: V74116, Baldy Butte SW-Blazing Saddles, V76167, Cole Anthill 2, 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: 3 isolated upper molars.

 

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 804: L dentary fragment with m3, m4.

 


LILLEGRAVEN, 1969

Localities: KUA-1, 22, 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 2872: DP3.

UA 2225: Fragmentary maxilla with UM1-3.

UA 2410: Fragmentary maxilla with UM2-3.

UA 3804, 3939: UM1.

UA 3227: UM2.

UA 3083, 3097, 3660, 4059: UM3.

UA 3347, 3375, 3812: UM4.

UA 3671: Fragmentary mandible with LC1, LP1 and LM2-3.

UA 3761: Fragmentary mandible with LP2-3, LM1-4.

UA 2789: Fragmentary mandible with LM1-4.

UA 4003: LP3.

UA 2553, 3569, 3717, 3813, 3917: LM1.

UA 2538, 3482, 3822: LM2.

UA 2237: LM3.

 


SLOAN & RUSSELL 1974

Locality: Scabby Butte, northwest of Lethbridge, Lethbridge County, Southwestern Alberta Province, Canada.

Horizon: St. Mary River Formation.

Biostratigraphy:

Age: Edmontonian age, Upper Campanian Stage- Lower Maastrichtian Stage, Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

NMC 9820: Right M3.

 


sp. cf. P. krejcii ROWE, CIFELLLI, LEHMAN & WEIL, 1992

Locality: Terlingua local fauna, OMNH V58 (TMM 43057), 8 km NNE Study Butte, Brewster County, Big Bend of the Rio Grande, Texas.

Horizon: Basal upper shale member, Agua Formation.

Biostratigraphy:

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

Material:


OMNH 22748:

 

cf. P. krejcii WHITMORE, 1988

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 12752: Partial left dentary with m1 and m2.

 


= Pediomys krejcii STORER, 1991

Locality: Gryde Local locality, Farm of Mr. Greg Gryde in Legal Subdivision 11, Section 19, Township 4, Range 18 West of the 3rd Meridian, Saskatchewan Province, Canada.

Horizon: Frenchman Formation.

Biostratigraphy:

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

Material:

P1927.606: LP1.

P1927.545, P1927.701, P1927.2036, P2004.17, P2004.497: RM1.

P1927.254, P1927.316, P1927.546: LM3.

P1927.477, P2004.16: RM3.

P2004.498: LM4.

P1927.600, P2004.75, P2004.499, P2004.500: RM1.

P1927.262, P1927.486, P2004.501: Rm1.

P1927.605, P1927.781: Rm2.

P2004.503: Rm4.

P1927.226, P1927.363, P1927.689: Lm1, m2, or m3.

P1927.252, p2004.504: Rm1, m2, or m3.

_____________________________________________________________________________________

Species: ?cooki (CLEMENS, 1966) DAVIS, 2007
Etymology:
= Pediomys cooki CLEMENS, 1966

Holotype: UCMP 47738

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: Fragmentary right maxilla with UP3 and UM1-3.

Referred material:

AMNH 58749: Fragment of maxilla with UP3 and UM1.

KU 12516: Fragment of maxilla with UM1-2.

KU 12954: Fragment of maxilla with UM1-3.

Numbers: Not given: plus 56 isolated teeth.

 

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 46400: Fragment of maxilla with UM3-4.

UCMP 51344: Fragment of maxilla with UM3-4.

UCMP 51333: Fragment of maxilla with UM3.

UCMP 51345: Fragment of maxilla with UM3.

UCMP 47473: Fragment of maxilla with UM2.

UCMP 47048: Fragment of maxilla with UM1.

Numbers: Not given: plus 57 isolated teeth.

 


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.

Horizon: Lance Formation.

Biostratigraphy:

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

Material:

UCMP 51602: Fragment of maxilla with UM1.

UCMP 5130: Fragment of maxilla with UM2.

UCMP 51434: Fragment of a right dentary with LM2-LM4, inclusive.

Numbers: Not given: plus 5 isolated teeth.

 

Localities: UCMP V-5002, V-5619, V-5709, 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-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: 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 117632: Fragment of RUM3.

 

= Leptalestes cooki BRAND, HECKERT, SANCHEZ, FOSTER, HUNT-FOSTER & EBERLE, 2022

Localtiy: J & M Site, Rio Blanco County, Colorado.

Horizon: Mesa Verde Group, Williams Fork Formation.

Biostratigraphy:

Age: Late Campanian-Early Maastrichtian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material:

MWC 8859: A left m2 or m3.

 


CLEMENS, 1973

Locality: San Juan Basin, New Mexico.

Horizon: Fruitland Formation.

Biostratigraphy:

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

Material:

Number: Not given.

 

SLOAN & RUSSELL, 1974

Locality: Scabby Butte, northwest of Lethbridge, Lethbridge County, Southwestern Alberta Province, Canada.

Horizon: St. Mary River Formation.

Biostratigraphy:

Age: Edmontonian age, Upper Campanian Stage- Lower Maastrichtian Stage, Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material:

NMC 21307: Buccal portion of right upper molar, probably 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 52511: LEft M3, UWBM 89435: Left m4.


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Species: prokrejcii (FOX, 1979) DAVIS, 2007
Etymology:
= Pediomys prokrejcii FOX, 1979

Holotype: UA 14817

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: Incomplete left maxillary fragment having UM1-2.

Referred material:


Locality: Montana.

Horizon: Judith River Formation.

Biostratigraphy:

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

Material:

AMNH 77375: Right upper molar.

 


Locality: UCMP V-77083, Makela’s French 1, Mammal 1, 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 131341: M1.

UCMP 130544: m2 or m3.

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Species: fassetti (RIGBY & WOLBERG, 1987) DAVIS, 2007
Etymology:
= Pediomys fassetti RIGBY & WOLBERG, 1987

Holotype: UNM-B1734

Locality: Quarry 1, Fossil Forest, San Juan Basin, New Mexico.

Horizon: Lower Kirtland Formation.

Biostratigraphy:

Age: Kirtlandian age, Upper Campanian Stage- Lower Maastrichtian Stage, Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: UM3 fragment.

Referred material:

UNM-B1738: UM1.

UNM-B1737: UM?2.

UNM-B1724: LM?3.

UNM-B1725: Broken LM1.

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Species: toevsi HUNTER, HEINRICH & WEISHAMPEL, 2010
Etymology: In honor of Art Toevs, who helped maintain the field camps during the 1988-90 field seasons for the expeditiosn by the Johns Hopkins University to the St. Mary River Formation.

Holotype: MOR 2505

Locality: Shell Hell, Mor Locality 703, SW 1/4 section 19, Township 31 North, Range 9 W, Glacier County, Montana.

Horizon: St. Mary River Formation.

Biostratigraphy:

Age: Edmontonian age, Upper Campanian Stage- Lower Maastrichtian Stage, Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Right maxilary fragment with M2-4.

Referred material:

MOR 2508: Isoalted RM4.

MOR 2506: Right mandibular fragment with incomplete m1.