ammonites
Egg Mountain, MOR TM-006 (Cretaceous of the United States)

Where: Teton County, Montana (47.8° N, 112.2° W: paleocoordinates 55.4° N, 78.7° W)

• coordinate based on political unit

• small collection-level geographic resolution

When: Two Medicine Formation, Judithian (83.5 - 70.6 Ma)

Environment/lithology: terrestrial; carbonate

Size classes: macrofossils, mesofossils

Collection methods: quarrying, surface (in situ), mechanical,

Primary reference: M. Montellano. 1988. Alphadon halleyi (Didelphidae, Marsupialia) from the Two Medicine Formation (Late Cretaceous, Judithian) of Montana. Journal of Vertebrate Paleontology 8(4):378-382 [J. Alroy/J. Alroy/R. Whatley] more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 14453: authorized by John Alroy, entered by John Alroy on 30.04.1994, edited by Matt Carrano

Creative Commons license: CC BY-NC-ND (attribution-noncommercial-no derivatives)

Egg Mountain, MOR TM-006: Judithian, Montana

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Insecta
Insecta indet. Linnaeus 1758
Mammalia - Allotheria
Paracimexomys sp. Archibald 1982
Database 2006 1 specimen
Cimexomys judithae Sahni 1972
recombined as Paracimexomys judithae
see also Montellano et al. 2000 (8 measurements)
Mammalia - Didelphimorphia - Alphadontidae
Alphadon halleyi Sahni 1972
Reptilia
Reptilia indet. Laurenti 1768
1 specimen
Reptilia - Squamata
Lacertilia indet. Owen 1842
4 specimens
Reptilia - Squamata - Varanidae
Varanidae indet. Hardwicke and Gray 1824
3 individuals
Reptilia - Squamata - Teiidae
Teiidae indet. Gray 1827
1 specimen
Reptilia - Dinosauria
Dinosauria indet. Owen 1842
1 specimen
Reptilia - Dinosauria - Thescelosauridae
Orodromeus makelai n. gen., n. sp. Horner and Weishampel 1988
20 individuals
individuals and egg clutches: includes the type specimen, MOR-294 (4 measurements)
Reptilia - Dinosauria - Prismatoolithidae
Prismatoolithus levis Zelenitsky and Hills 1996
Zelenitsky 2000
Reptilia - Dinosauria - Dromaeosauridae
Dromaeosauridae indet. Colbert and Russell 1969
1 individual
Reptilia - Dinosauria - Troodontidae
Troodon cf. formosus Leidy 1856
5 individuals
individuals and egg clutches
Troodon formosus Leidy 1856
Varricchio et al. 2002 4 specimens
parent taxon of P. levis; MOR 299, 393, 675, 963
Reptilia - Testudines - Chelydridae
Chelydridae indet. Swainson 1839
1 individual
see common names

Geography
Country:United States State/province:Montana County:Teton
Coordinates: 47.8° North, 112.2° West (view map)
Paleocoordinates:55.4° North, 78.7° West
Basis of coordinate:based on political unit
Geographic resolution:small collection
Time
Period:Cretaceous Epoch:Late/Upper Cretaceous
Stage:Campanian 10 m.y. bin:Cretaceous 7
Key time interval:Judithian
Age range of interval:83.5 - 70.6 m.y. ago
Age estimate:76.0 to 75.7 Ma (AEO)
Stratigraphy
Formation:Two Medicine
Lithology and environment
Primary lithology:very fine "carbonate"
Includes fossils?Y
Environment:terrestrial indet.
Taphonomy
Modes of preservation:body
Degree of concentration:concentrated
Size of fossils:macrofossils,mesofossils
Spatial orientation:preferred
Associated major elements:many
Disassociated major elements:many
Disassociated minor elements:some
Spatial resolution:autochthonous
Collection methods and comments
Collection methods:selective quarrying,surface (in situ),mechanical,field collection,survey of museum collection
Reason for describing collection:general faunal/floral analysis
Taxonomic list comments: within "Lithofacies 4," dated at 76.7 Ma (apparently using SCLF AA, but error and method not given): Horner et al. 2001
Metadata
Database number:14453
Authorizer:J. Alroy, M. Carrano Enterer:J. Alroy, M. Carrano
Modifier:M. Carrano Research group:vertebrate
Created:1994-04-30 00:00:00 Last modified:2010-08-21 08:40:44
Access level:the public Released:1994-04-30 00:00:00
Creative Commons license:CC BY-NC-ND
Reference information
Primary reference:
2601 M. Montellano. 1988. Alphadon halleyi (Didelphidae, Marsupialia) from the Two Medicine Formation (Late Cretaceous, Judithian) of Montana. Journal of Vertebrate Paleontology 8(4):378-382 [J. Alroy/J. Alroy/R. Whatley]

Secondary references:

17718ETE M.O.R. Database. 2006. [M. Carrano/M. Carrano]
14356ETE K. F. Hirsch and B. Quinn. 1990. Eggs and eggshell fragments from the Upper Cretaceous Two Medicine Formation of Montana. Journal of Vertebrate Paleontology 10(4):491-511 [M. Carrano/K. Maguire/M. Carrano]
14331ETE J. R. Horner. 1994. Comparative taphonomy of some dinosaur and extant bird colonial nesting grounds. K. Carpenter, K.F. Hirsch & J.R. Horner (eds.) Dinosaur Eggs and Babies. Cambridge University Press, Cambridge 116-123 [M. Carrano/K. Maguire/M. Carrano]
14260ETE J. R. Horner. 1997. Rare preservation of an incompletely ossified fossil embryo. Journal of Vertebrate Paleontology 17(2):431-434 [M. Carrano/M. Carrano/M. Carrano]
33367ETE D. J. Varricchio, J. R. Horner, and F. D. Jackson. 2002. Embryos and eggs for the Cretaceous theropod dinosaur Troodon formosus. Journal of Vertebrate Paleontology 22(3):564-576 [M. Carrano/M. Carrano]
14294ETE D. K. Zelenitsky. 2000. Dinosaur eggs from Asia and North America. Y.-N. Lee (ed.), 2000 International Dinosaur Symposium for Kosong County in Korea. Paleontological Society of Korea Special Publication 4:13-26 [M. Carrano/M. Carrano/M. Carrano]