Clambank Hollow Quarry (Cretaceous to of the United States)

Where: Chouteau County, Montana (47.8° N, 109.6° W: paleocoordinates 54.9° N, 75.8° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Judith River Formation (Montana Group), Middle Campanian to Middle Campanian (83.5 - 70.6 Ma)

• 40 feet below top of formation; Judithian based on fauna

• group of beds-level stratigraphic resolution

Environment/lithology: fine channel fill; lenticular, carbonaceous claystone

• "river meander or oxbow lake"
• "a crescentic lens rapidly pinching out to the E and dipping very steeply to the W...2 feet in thickness and can be divided into two parts, a lower subdivision not more than 6 inches thick which is very rich in bones, and an upper extremely well indurated subdivision with less bone concentration. Both lenses contain coal lenticles and plant debris."

Size class: mesofossils

Collected in 1964-1966; reposited in the AMNH

Collection methods: bulk, sieve,

Primary reference: A. Sahni. 1972. The vertebrate fauna of the Judith River Formation, Montana. Bulletin of the American Museum of Natural History 147(6):321-412 [J. Alroy/J. Alroy/M. Carrano]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 14446: authorized by John Alroy, entered by John Alroy on 30.04.1994, edited by Matthew Carrano, Patricia Holroyd, Roger Benson and Philip Mannion

Creative Commons license: CC BY (attribution)

Taxonomic list

• "about 75 Ma" according to Swisher AA date: Rogers pers. commun. 15.4.94NISP 268
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Gastropoda
 Heterostropha - Valvatidae
? Valvata montanensis
 Cerithioidea - Pleuroceridae
Goniobasis sp., ? Goniobasis subtortuosa
Goniobasis sp. Lea snail
 Architaenioglossa - Viviparidae
Lioplacodes judithensis, Viviparus sp.
Viviparus sp. Montfort 1810 snail
Bivalvia
 Unionida - Unionidae
Unio sp.
Unio sp. Philipsson 1788 freshwater mussel
 Cardiida - Sphaeriidae
Sphaerium planum
Sphaerium planum fingernail clam
Mammalia
 Theriamorpha - Pediomyidae
"Pediomys clemensi n. sp." = Protolambda clemensi, "Pediomys prokrejcii" = Leptalestes prokrejcii4
"Pediomys clemensi n. sp." = Protolambda clemensi Sahni 1972 metatherian
"Pediomys prokrejcii" = Leptalestes prokrejcii4 Fox 1979 metatherian
 Theriamorpha - Stagodontidae
Eodelphis sp.1
Eodelphis sp.1 Matthew 1916 metatherian
 Polydolopimorphia -
Ectocentrocristus foxi n. sp.10
Ectocentrocristus foxi n. sp.10 Rigby and Wolberg 1987 metatherian
 Theriamorpha - Alphadontidae
Alphadon attaragos2, Alphadon halleyi n. sp., Turgidodon russelli3, "Alphadon praesagus" = Turgidodon praesagus
Alphadon attaragos2 Lillegraven and McKenna 1986 metatherian
pers. commun.
Alphadon halleyi n. sp. Sahni 1972 metatherian
includes "A. sahnii" of Lillegraven and McKenna 1986
Turgidodon russelli3 Fox 1979 metatherian
"Alphadon praesagus" = Turgidodon praesagus Russell 1952 metatherian
 Theriamorpha - Gypsonictopidae
Gypsonictops lewisi n. sp.
Gypsonictops lewisi n. sp. Sahni 1972 eutherian
 Cimolesta - Cimolestidae
Cimolestes sp.2, cf. Batodon sp.2
Cimolestes sp.2 Marsh 1889 eutherian
pers. commun.
cf. Batodon sp.2 Marsh 1892 eutherian
pers. commun.
 Theriamorpha -
Paranyctoides sp.2
Paranyctoides sp.2 Fox 1979 eutherian
pers. commun.
 Multituberculata -
Cimexomys judithae n. sp.
Cimexomys judithae n. sp. Sahni 1972 multituberculate
one specimen is Paracimexomys sp.: Montellano 1992
 Multituberculata - Neoplagiaulacidae
"Mesodma primaeva" = Filikomys primaevus, Mesodma sp.2
"Mesodma primaeva" = Filikomys primaevus Lambe 1902 multituberculate
"primaevus": OK according to Novacek and Clemens 1977; one specimen from "40 feet east of Clambank Hollow Quarry and on the opposite side of the gully"
Mesodma sp.2 Jepsen 1940 multituberculate
pers. commun.
 Multituberculata - Cimolodontidae
Cimolodon sp.
Cimolodon sp. Marsh 1889 multituberculate
 Multituberculata -
"Cimexomys magnus n. sp." = Paracimexomys magnus
"Cimexomys magnus n. sp." = Paracimexomys magnus Sahni 1972 multituberculate
 Multituberculata - Cimolomyidae
Meniscoessus major, Cimolomys clarki
Meniscoessus major Russell 1936 multituberculate
Cimolomys clarki Sahni 1972 multituberculate
Reptilia
 Squamata - Chamopsiidae
Leptochamops denticulatus
Leptochamops denticulatus Gilmore 1928 squamates
 Squamata - Teiidae
Teiidae indet.6
Teiidae indet.6 Gray 1827 squamates
AMNH 8487, 8488
 Squamata - Xenosauridae
Exostinus lancensis
Exostinus lancensis Gilmore 1928 squamates
 Squamata -
Paraderma bogerti
Paraderma bogerti Estes 1964 squamates
 Squamata - Anguidae
"Peltosaurus piger" = Odaxosaurus piger
"Peltosaurus piger" = Odaxosaurus piger Gilmore 1928 squamates
 Squamata -
Parasaniwa wyomingensis
Parasaniwa wyomingensis Gilmore 1928 squamates
 Testudinata - Baenidae
? Baenidae indet.
? Baenidae indet. Cope 1882 turtle
 Ornithischia - Ceratopsidae
Ceratopsidae indet.
Ceratopsidae indet. Marsh 1888 ceratopsid
 Ornithischia -
"? Stegoceras validus" = Stegoceras validum
"? Stegoceras validus" = Stegoceras validum Lambe 1902 ornithischian
 Ornithischia - Hadrosauridae
"Kritosaurus cf. breviceps" = Hadrosaurus breviceps, "Procheneosaurus altidens" = Trachodon altidens
"Kritosaurus cf. breviceps" = Hadrosaurus breviceps Marsh 1889 hadrosaurid
"Procheneosaurus altidens" = Trachodon altidens Lambe 1902 hadrosaurid
 Ornithischia -
Orodromeus makelai5
Orodromeus makelai5 Horner and Weishampel 1988 ornithopod
 Ornithischia - Nodosauridae
Edmontonia longiceps
Edmontonia longiceps Sternberg 1928 ankylosaur
 Theropoda -
Paronychodon lacustris
Paronychodon lacustris Cope 1876 maniraptoran
 Theropoda - Troodontidae
Troodon formosus
Troodon formosus Leidy 1856 maniraptoran
Amphibia
 Temnospondyli - Albanerpetontidae
Albanerpetontidae indet.7
Albanerpetontidae indet.7 Fox and Naylor 1982 tetrapod
AMNH 8479, 8480
 Salientia -
Anura "Unnamed genus and species I"9, Anura "indet. 1"9, Anura "indet. 3"9, Hensonbatrachus kermiti9, cf. Scotiophryne sp.9
Anura "Unnamed genus and species I"9 Fischer von Waldheim 1813 frog
AMNH FARB 8460*, maxilla; = Discoglossid C of Sahni
Anura "indet. 1"9 Fischer von Waldheim 1813 frog
AMNH FARB 8451*, 8464*, 33044*, maxillae; = Discoglossid B of Sahni
Anura "indet. 3"9 Fischer von Waldheim 1813 frog
AMNH FARB 8462*, 33040*, 33041*, 33046*, maxillae
Hensonbatrachus kermiti9 Gardner and Brinkman 2015 frog
AMNH FARB 33042*, 33043*, maxillae - Discoglossid A (in part)
cf. Scotiophryne sp.9 Estes 1969 frog
AMNH FARB 33045*
 Proteida - Batrachosauroididae
Prodesmodon copei
Prodesmodon copei Estes 1964 salamander
 Caudata - Urodela
Habrosaurus sp.8
Habrosaurus sp.8 Gilmore 1928 siren
Actinopteri
 Elopiformes - Phyllodontidae
? Paralbula sp.
? Paralbula sp. Blake 1940
 Aspidorhynchiformes - Aspidorhynchidae
Belonostomus longirostris
1Alroy 2002; 2Carrano 1999; 3Cifelli 1990; 4Fox 1979; 5Galton 1995; 6Gao and Fox 1996; 7Gardner 2000; 8Gardner 2003; 9Gardner et al. 2016; 10Rigby and Wolberg 1987