Where: Las Animas County, Colorado (37.2° N, 103.6° W: paleocoordinates 36.9° N, 66.6° W)
• coordinate based on nearby landmark
• outcrop-level geographic resolution
When: Lincoln Limestone Member (Greenhorn Limestone Formation), Middle Cenomanian (99.6 - 93.5 Ma)
• The vertebrate-rich calcarenite unit discussed in this paper is located approximately 2.5 m above the contact between the noncalcareous Graneros Shale and calcareous Greenhorn Limestone. Ostrea beloiti and I. cf. I. rutherfordi range from the Middle Cenomanian (96 Ma) to the early Late Cenomanian (ca. 94.6 Ma), and from middle Middle Cenomanian (ca. 95 Ma) to possibly as late as early Late Cenomanian (ca. 94.55 Ma), respectively (Kauffman et al., 1993, fig. 7). Thus, the concurrent age of occurrence for these two bivalve taxa is 95–94.5 Ma, which dictates that the vertebrate-rich horizon is no older than the middle Middle Cenomanian (ca. 95 Ma). Based upon the similarity of our data with those presented by Kauffman et al. (1993, fig. 7), and considering the close proximity of the calcarenite layers to the X-bentonite, we think that the age of the vertebrate-rich horizon is somewhere between middle Middle Cenomanian (ca. 95 Ma) and late Middle Cenomanian (ca. 94.7 Ma).
• group of beds-level stratigraphic resolution
Environment/lithology: deep subtidal ramp; lithified grainstone
Size classes: macrofossils, mesofossils
Collection methods: bulk, surface (float), chemical,
• Repository: Sternberg Museum of Natural History, Fort Hays State University (FHSM), Hays, Kansas
Primary reference: K. Shimada, J. A. Parkin, J. M. Palermo and B. A. Schumacher. 2003. Late Cretaceous marine vertebrates from the basal Greenhorn Limestone in southeastern Colorado. Journal of Vertebrate Paleontology 23(3):96A [J. Alroy/J. Alroy/J. Alroy]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, edited by Matthew Clapham
Creative Commons license: CC BY (attribution)
Taxonomic list
Bivalvia | |
Ostrea beloiti Logan 1899 oyster | |
Cephalopoda | |
| |
Reptilia | |
| |
cf. Brachauchenius sp. Williston 1903 plesiosaur | |
| |
| |
| |
Actinopteri | |
Protosphyraena sp. Leidy 1857 | |
? Plethodidae indet.2 Loomis 1900 | |
Albulidae indet. Bleeker 1859 bonefish | |
Enchodus cf. shumardi Leidy 1856
Enchodus cf. gladiolus Cope 1872 | |
Xiphactinus audax Leidy 1870 | |
cf. Pachyrhizodus sp.2 Agassiz 1850
cf. Pachyrhizodus minimus2 Stewart 1899 | |
Micropycnodon cf. kansasensis2 Hibbard and Graffham 1941 | |
cf. Palaeobalistum sp.2 Blainville 1818
"Nursallia" sp.2 Blot 1987 | |
Chondrichthyes | |
Ptychodus cf. anonymus Williston 1900 elasmobranch
Ptychodus decurrens Agassiz 1838 elasmobranch
Ptychodus occidentalis Leidy 1868 elasmobranch | |
| |
| |
Cretodus semiplicatus Agassiz 1843 mackerel shark | |
"Carcharias tenuiplicatus" = Eostriatolamia tenuiplicatus, "Carcharias saskatchewanensis" = Microcarcharias saskatchewanensis, Johnlongia cf. parvidens2, "Megachasma comanchensis n. sp." = Pseudomegachasma comanchensis1
"Carcharias tenuiplicatus" = Eostriatolamia tenuiplicatus Cappetta and Case 1975 sand tiger shark
"Carcharias saskatchewanensis" = Microcarcharias saskatchewanensis Case et al. 1990 sand tiger shark | |
"Cretolamna appendiculata" = Cretalamna appendiculata, "Cretalamna appendiculata" = Cretalamna appendiculata2
"Cretolamna appendiculata" = Cretalamna appendiculata Agassiz 1835 mackerel shark | |
Squalicorax curvatus Williston 1900 crow shark
Squalicorax falcatus Agassiz 1843 crow shark | |
| |
"Carcharias amonensis" = Haimirichia amonensis
"Carcharias amonensis" = Haimirichia amonensis Cappetta and Case 1975 mackerel shark | |
Cretomanta canadensis Case et al. 1990 mackerel shark | |
Cretoxyrhina mantelli Agassiz 1835 mackerel shark | |
| |
| |
Rhinobatos incertus Cappetta 1973 guitarfish |