Comanche National Grassland (Cretaceous to of the United States)

Where: Baca County, Colorado (37.0° N, 102.7° W: paleocoordinates 36.5° N, 65.8° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Lincoln Limestone Member (Greenhorn Limestone Formation), Middle Cenomanian to Middle Cenomanian (99.6 - 93.5 Ma)

• "lowermost part of the Lincoln Limestone... middle/early late Cenomanian"

• group of beds-level stratigraphic resolution

Environment/lithology: grainstone

• "calcarenite beds"

Size classes: macrofossils, mesofossils

Collection methods: bulk, surface (float), chemical,

• "surface collecting and acid treatment"

Primary reference: K. Shimada, B. A. Schumacher, J. A. Parkin and J. M. Palermo. 2006. Fossil marine vertebrates from the lowermost Greenhorn Limestone (Upper Cretaceous: Middle Cenomanian) in southeastern Colorado. Journal of Paleontology 80(sp 63):1-45 [M. Carrano/H. Street]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 35429: authorized by John Alroy, entered by John Alroy on 12.12.2003

Creative Commons license: CC BY (attribution)

Taxonomic list

• some molluscs may be omitted
Bivalvia
 Myalinida - Inoceramidae
 Ostreida - Ostreidae
Ostrea beloiti Logan 1899 oyster
Cephalopoda
 Ammonitida - Acanthoceratidae
Eucalycoceras sp. Spath 1923 ammonite
Chondrichthyes
 Hybodontiformes - Ptychodontidae
Ptychodus decurrens Agassiz 1839 elasmobranch
 Euselachii -
Cretomanta canadensis Case et al. 1990 elasmobranch
 Rajiformes - Rhinobatidae
Rhinobatos incertus Cappetta 1973 guitarfish
 Lamniformes - Anacoracidae
Squalicorax curvatus Williston 1900 crow shark
Squalicorax falcatus Agassiz 1843 crow shark
 Lamniformes - Archaeolamnidae
Archaeolamna sp. Siverson 1992 mackerel shark
 Lamniformes - Cretoxyrhinidae
Cretoxyrhina mantelli Agassiz 1843 mackerel shark
Cretolamna appendiculata Agassiz 1843 mackerel shark
Cretodus semiplicatus Agassiz 1843 mackerel shark
 Lamniformes - Odontaspididae
"Cretolamna cf. woodwardi" = Pseudoisurus tomosus Glikman 1957 sand tiger shark
Actinopteri
 Albuliformes - Albulidae
Albulidae indet. Bleeker 1859 bonefish
 Salmoniformes - Enchodontidae
 Ichthyodectiformes - Ichthyodectidae
Xiphactinus audax Leidy 1870
 Pachycormiformes - Pachycormidae
Protosphyraena sp. Leidy 1857
 Pycnodontiformes - Pycnodontidae
Pycnodontidae indet. Agassiz 1835
Reptilia
 Squamata - Dolichosauridae
 Sauropterygia - Polycotylidae
cf. Trinacromerum sp. Cragin 1888 plesiosaur
 Sauropterygia - Pliosauridae
cf. Brachauchenius sp. Williston 1903 plesiosaur