Medicine Rocks Site 1: Torrejonian, Montana

List of taxa
Where & when
Taphonomy & methods
Metadata & references
Taxonomic list
cf. Scotiophryne sp. Estes 1969
    = Anura indet.
Gardner and DeMar 2013
Discoglossidae indet. Günther 1859
said to be a new genus
    = Anura indet.
Gardner and DeMar 2013
Chondrichthyes - Myliobatiformes - Dasyatidae
Dasyatidae indet. Jordan 1888
Actinopteri - Acipenseriformes - Polyodontidae
cf. Paleopsephurus sp. MacAlpin 1947
Actinopteri - Acipenseriformes - Acipenseridae
cf. Acipenser sp. Linnaeus 1758
Actinopteri - Amiiformes - Palaeolabridae
Palaeolabrus cf. montanensis Estes 1969
Actinopteri - Amiiformes - Amiidae
Amia fragosa Jordan 1927
Amia uintaensis (Leidy 1873)
nomen dubium belonging to Amiinae
Actinopteri - Lepisosteiformes - Lepisosteidae
Lepisosteus occidentalis (Leidy 1856)
original and current combination Lepidotus occidentalis
Proteida - Batrachosauroididae
Opisthotriton kayi Auffenberg 1961
Habrosaurus dilatus Gilmore 1928
Scapherpeton tectum Cope 1876
Lisserpeton bairdi Estes 1965
Reptilia - Testudines
Compsemys victa (Leidy 1856)
Reptilia - Testudines - Baenidae
Palatobaena bairdi Gaffney 1972
Archibald and Hutchison 1979
CCM 77-11 (three-quarters of undistorted skull)
Reptilia - Testudines
Hutchemys rememdium n. gen., n. sp. Joyce et al. 2009
Joyce et al. 2009
YPM PU 16795 - holotype (a nearly complete postcranial skeleton); referred specimen: YPM PU 16781 (right hyo/hypoplastron)
cf. Plastomenus sp. Cope 1873
Reptilia - Crocodylia
Leidyosuchus sp. Lambe 1907
    = Crocodylia indet. Owen 1842
Alroy 2007
Reptilia - Alligatoridae
Alligatorinae indet. Cuvier 1807
Reptilia - Squamata - Xenosauridae
Exostinus lancensis Gilmore 1928
1 specimen
PU 16780, anterior end of left maxilla
Reptilia - Squamata - Necrosauridae
cf. Provaranosaurus sp. Gilmore 1942
6 specimens
PU 16779a–e, broken left maxilla with two teeth, fragment of left maxilla with one tooth, fragment of left dentary with no teeth preserved, fragment of right dentary with one tooth. PU 16782, posterior end of right dentary with one tooth.
Reptilia - Squamata - Anguidae
cf. Gerrhonotus sp. Wiegmann 1828
9 specimens
PU 16778a, almost complete right dentary; 16778b, posterior half of left dentary. Unnumbered fragments of three right and three left dentaries; one questionably referred posterior half of left dentary.
Pancelosaurus piger (Gilmore 1928)
recombined as Odaxosaurus piger
PU 17034, posterior ends of two right and three left dentaries, the anterior end of a left maxilla, and one tooth bearing fragment. Numerous unnumbered osteoscutes, complete and partly co-ossified frontals, and another frontal fragment.
Reptilia - Squamata
Coniophis sp. Marsh 1892
1 specimen
PU 16773, nine vertebrae, most of them eroded and broken
    = cf. Coniophis precedens Marsh 1892
Longrich et al. 2012
YPM-PU 16773
cf. Dunnophis sp. Hecht 1959
1 specimen
PU 16774, eleven eroded and broken vertebrae.
    = cf. Coniophis precedens Marsh 1892
Longrich et al. 2012
YPM-PU 16774
Reptilia - Squamata - Globauridae
Contogenys sloani Estes 1969
Estes 1969 3 specimens
YPM-PU 17035, right dentary; 17036a, broken left dentary; 17036b, post. end of right dentary with associated coronoid, splenial, and parts of surangular and angular
    = Contogenys ekalakaensis n. sp. Nydam and Fitzpatrick 2009
Nydam and Fitzpatrick 2009
17035 is the holotype
Reptilia - Squamata - Oligodontosauridae
cf. Oligodontosaurus sp. Gilmore 1942
2 specimens
PU 18577, almost complete trunk vertebra; 16777, posterior part of right dentary.
    = Oligodontosaurus cf. wyomingensis Gilmore 1942
Longrich et al. 2015
YPM-PU 16777 (left dentary)
Reptilia - Squamata - Xantusiidae
Palaeoxantusia fera Hecht 1956
5 specimens
PU 16775, complete right dentary; 16776, posterior part of left dentary with associated angular and part of surangular; three other unnumbered fragments of dentaries, two left, one right.
Champsosaurus sp. Cope 1876
Mammalia - Primates - Plesiadapidae
Pronothodectes cf. matthewi Gidley 1923
Gingerich 1976
Mammalia - Primates - Picrodontidae
Picrodus silberlingi Douglass 1908
Scott and Fox 2005
Mammalia - Primates - Carpolestidae
Elphidotarsius cf. florencae Gidley 1923
Rose 1975
Mammalia - Ungulata - Phenacodontidae
Tetraclaenodon puercensis (Cope 1881)
Thewissen 1990
Mammalia - Multituberculata - Neoplagiaulacidae
Parectypodus sylviae (Rigby 1980)
Sloan 1987
Mesodma pygmaea Sloan 1987
Sloan 1987
Mammalia - Multituberculata - Ptilodontidae
Baiotomeus lamberti n. sp. Krause 1987
Krause 1987
see common names

Country:United States State/province:Montana County:Carter
Coordinates: 46.1° North, 104.5° West (view map)
Paleocoordinates:51.8° North, 81.0° West
Basis of coordinate:stated in text
Geographic resolution:outcrop
Period:Paleogene Epoch:Paleocene
Stage:Danian 10 m.y. bin:Cenozoic 1
Key time interval:Torrejonian
Age range of interval:63.30000 - 61.70000 m.y. ago
* legacy (obsolete) database fields
Formation:Fort Union Member:Ekalaka
Local section:Medic Local bed:1
Local order:bottom to top
Stratigraphy comments: "The Medicine Rocks Sandstone, a unit that was originally mapped as part of the Tongue River Member of the Fort Union Formation. More recent work, however, has shown that the Medicine Rocks Sandstone is bounded by unconformities and it has thus been designated as its own unit, now called the Ekalaka Member of the Fort Union Formation YPM PU 16781 is from “Locality 1,” which Sloan (1970) grouped with other localities into an assemblage named Medicine Rocks I. A tentative Torrejonian 3 age is typically given on the basis of the mammalian assemblage found at that site (e.g., Lofgren et al. 2004)" (Joyce et al. 2009)
Lithology and environment
Primary lithology: sandstone
Lithology description: "sandstone" (Estes 1976)
Environment:terrestrial indet.
Geology comments: "freshwaters of a warm temperate coastal plain" (Estes 1976)
Modes of preservation:body
Size of fossils:mesofossils
Collection methods and comments
Collection excludes:some genera
Collection methods:surface (float)
Reason for describing collection:taxonomic analysis
Taxonomic list comments:said to be To3
several other localities in this area are Tiffanian
Site III and Mehling Site are "at essentially the same stratigraphic level": Krause 1987a
possibly relevant: Pantolambda bathmodon Simons 1960: "probably occurs in the Medicine Rocks local fauna" Pantolambda cavirictum Simons 1960: "Medicine Rock local fauna"
SEE Sloan 1970
Also known as:Medicine Rocks I
Database number:14874
Authorizer:J. Alroy, P. Holroyd, M. Carrano, P. Mannion Enterer:J. Alroy, P. Holroyd, M. Carrano, P. Mannion
Modifier:P. Mannion Research group:vertebrate
Created:1994-04-30 00:00:00 Last modified:2012-12-21 06:39:36
Access level:the public Released:1994-04-30 00:00:00
Creative Commons license:CC BY
Reference information

Primary reference:

23573. R. Estes. 1976. Middle Paleocene lower vertebrates from the Tongue River Formation, southeastern Montana. Journal of Paleontology 50(3):500-520 [J. Alroy/J. Alroy]

Secondary references:

19636 J. Alroy. 2007. Synonymies and reidentifications of North American fossil vertebrates and so forth. [J. Alroy/J. Alroy]
38165 J. D. Archibald and J. H. Hutchison. 1979. Revision of the genus Palatobaena (Testudines, Baenidae), with the description of a new species. Postilla 177:1-19 [P. Mannion/P. Mannion/P. Holroyd]
12167ETE R. Estes. 1969. A scincoid lizard from the Cretaceous and Paleocene of Montana. Breviora 331:1-9 [M. Carrano/M. Carrano/R. Benson]
65027 J. D. Gardner and D. E. DeMar. 2013. Mesozoic and Palaeocene lissamphibian assemblages of North America: a comprehensive review. Palaeobiodiversity and Palaeoenvironments 93:459-515 [P. Holroyd/P. Holroyd/P. Holroyd]
1635 P. D. Gingerich. 1976. Cranial Anatomy and Evolution of Early Tertiary Plesiadapidae (Mammalia, Primates). University of Michigan Papers on Paleontology 15:1-141 [J. Alroy/J. Alroy/P. Mannion]
44082 W. G. Joyce, A. Revan, T. R. Lyson and I. G. Danilov. 2009. Two new plastomenine softshell turtles from the Paleocene of Montana and Wyoming. Bulletin of the Peabody Museum of Natural History 50(2):307-325 [P. Mannion/P. Mannion]
2160 D. W. Krause. 1987. Baiotomeus, a New Ptilodontid Multituberculate (Mammalia) from the Middle Paleocene of Western North America . Journal of Paleontology 61(3):595-603 [J. Alroy/J. Alroy/J. Ju]
42713 N. R. Longrich, B.-A. S. Bhullar, and J. A. Gauthier. 2012. A transitional snake from the Late Cretaceous period of North America. Nature 488:205-208 [P. Mannion/P. Mannion]
54822 N. R. Longrich, J. Vinther, R. A. Pyron, D. Pisani, and J. A. Gauthier. 2015. Biogeography of worm lizards (Amphisbaenia) driven by end-Cretaceous mass extinction. Proceedings of the Royal Society, B 282:20143034 [P. Mannion/P. Mannion]
31563ETE R. L. Nydam and B. M. Fitzpatrick. 2009. The occurrence of Contogenys-like lizards in the Late Cretaceous and Early Tertiary of the Western Interior of the U.S.A. Journal of Vertebrate Paleontology 29(3):677-701 [M. Carrano/M. Carrano/P. Mannion]
2947 K. D. Rose. 1975. The Carpolestidae: Early Tertiary primates from North America. Bulletin of the Museum of Comparative Zoology 147(1) [J. Alroy/J. Alroy/J. Ju]
14679 C. S. Scott and R. C. Fox. 2005. Windows on the evolution of Picrodus (Plesiadapiformes: Primates): morphology and relationships of a species complex from the Paleocene of Alberta. Journal of Paleontology 79(4):635-657 [J. Alroy/J. Alroy]
3196 R. E. Sloan. 1987. Paleocene and latest Cretaceous mammal ages, biozones, magnetozones, rates of sedimentation, and evolution. Geological Society of America Special Paper 209:165-200 [J. Alroy/J. Alroy/M. Uhen]
3401 J. G. M. Thewissen. 1990. Evolution of Paleocene and Eocene Phenacodontidae (Mammalia, Condylarthra). University of Michigan Papers on Paleontology 29:1-107 [J. Alroy/J. Alroy/P. Mannion]