Williams Fork Formation Explained

Williams Fork Formation
Type:	Geological formation
Period:	Campanian - Maastrichtian
Age:	Campanian (Edmontonian) ~
Prilithology:	Mudstone
Otherlithology:	Sandstone
Region:	Colorado
Coordinates:	40°N -108.8°W
Paleocoordinates:	47.5°N -80.3°W
Unitof:	Mesaverde Group

The Williams Fork Formation is a Campanian to Maastrichtian (Edmontonian) geologic formation of the Mesaverde Group in Colorado. Dinosaur remains are among the fossils that have been recovered from the formation, most notably Pentaceratops sternbergii,^[1] . Other fossils found in the formation are the ammonite Lewyites, tyrannosaurids, dromaeosaurids, troodontids, nodosaurids, ankylosaurids, hadrosaurids, hybodonts, neosuchian crocodylomorphs, and the mammals Glasbius and Meniscoessus collomensis.^{[2] [3]}

See also

• List of dinosaur-bearing rock formations
  • List of stratigraphic units with indeterminate dinosaur fossils

References

Bibliography

• Book: . David B. . . Peter . . Halszka . 2004 . The Dinosauria. 2nd . Berkeley. University of California Press . 1–880 . 2019-02-21. 0-520-24209-2.
• Diem, Stephen Daniel. (1999). Vertebrate Faunal Analysis of the Upper Cretaceous Williams Fork Formation, Rio Blanco County, Colorado [Master’s Thesis]. San Diego State University.

Further reading

• Archibald, J. D. (1987). Late Cretaceous (Judithian and Edmontonian) Vertebrates and Geology of the Williams Fork Formation. N.W. Colorado. In P. J. Currie, E. H. Koster, & Royal Tyrrell Museum of Palaeontology (Eds.), Fourth Symposium on Mesozoic Terrestrial Ecosystems: Drumheller, August 10-14, 1987: Short Papers (Rev. ed, pp. 7–11). Tyrrell Museum of Palaeontology.
• Brand, N., Heckert, A., Sanchez, I., Foster, J., Hunt-Foster, R., & Eberle, J. (2022). New Upper Cretaceous Microvertebrate Assemblage from the Williams Fork Formation, northwestern Colorado, U.S.A., and its Paleoenvironmental Implications. Acta Palaeontologica Polonica, 67(3), 579–600. https://doi.org/10.4202/app.00934.2021.
• Cifelli, R. L., Eberle, J. J., Lofgren, D. L., Lillegraven, J. A., & Clemens, W. A. (2004). Mammalian Biochronology of the Latest Cretaceous. In M. O. Woodburne (Ed.), Late Cretaceous and Cenozoic Mammals of North America: Biostratigraphy and Geochronology (pp. 21–42). Columbia University Press. https://www.jstor.org/stable/10.7312/wood13040.8.
• Diem, Stephen Daniel. (1999). Vertebrate Faunal Analysis of the Upper Cretaceous Williams Fork Formation, Rio Blanco County, Colorado [Master’s Thesis]. San Diego State University.
• Noll, M. D. (1998). Sedimentology of the Upper Cretaceous Williams Fork Formation, Rio Blanco County, Northwestern Colorado [Master’s Thesis]. San Diego State University. https://digitallibrary.sdsu.edu/islandora/object/sdsu%3A17
• J. R. Foster and R. K. Hunt-Foster. 2015. First report of a giant neosuchian (Crocodyliformes) in the Williams Fork Formation (Upper Cretaceous: Campanian) of Colorado. Cretaceous Research 55:66-73
• Lockley, M. G., Smith, J. A., & King, M. R. (2018). First reports of turtle tracks from the Williams Fork Formation (‘Mesaverde’ Group), Upper Cretaceous (Campanian) of western Colorado. Cretaceous Research, 84, 474–482. https://doi.org/10.1016/j.cretres.2017.11.001.
• W. J. Kennedy, W. A. Cobban, and G. R. Scott. 2000. Heteromorph ammonites from the Upper Campanian (Upper Cretaceous) Baculites cuneatus and Baculites reesidei zones of the Pierre Shale in Colorado, USA. Acta Geologica Polonica 50:1-20
• J. A. Lillegraven. 1987. Stratigraphic and evolutionary implications of a new species of Meniscoessus (Multituberculata, Mammalia) from the Upper Cretaceous Williams Fork Formation, Moffat County, Colorado. Dakoterra 3:46-56
• Sullivan, R.M., and Lucas, S.G. 2006. "The Kirtlandian land-vertebrate "age" – faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America." New Mexico Museum of Natural History and Science, Bulletin 35:7-29.

Notes and References

1. Diem. Steve. Archibald. James D.. Range extension of southern chasmosaurine Ceratopsian dinosaurs into northwestern Colorado. Journal of Paleontology. 2005. 79. 2. 251–258. 10.1666/0022-3360(2005)079<0251:REOSCC>2.0.CO;2. 2005JPal...79..251D . 21 September 2016. 10.1.1.538.7263. 17715685 .
2. https://paleobiodb.org/classic/displayCollResults?collection_no=14497 Jubb Creek
3. https://paleobiodb.org/classic/displayCollResults?collection_no=76715 Rangely South (SDNHM)