Multicolored (variegated) beds of the Morrison Formation at Como Bluff, Wyoming. Many historical dinosaur sites are located along the flanks of the bluff. The Sundance Formation is visible as the reddish beds at the base of the bluff.
Como Bluff is a long ridge extending east–west, located between the towns of Rock River and Medicine Bow, Wyoming. The ridge is an anticline, formed as a result of compressional geological folding. Three geological formations, the Sundance, the Morrison, and the Cloverly Formations, containing fossil remains from the Late Jurassic of the Mesozoic Era are exposed.
Nineteenth-century paleontologists discovered many well-preserved specimens of dinosaurs, as well as mammals, turtles, crocodilians, and fish from the Morrison Formation. Because of this, Como Bluff is considered to be one of the major sites for the early discovery of dinosaur remains. Among the species discovered is the only known specimen of Coelurus. Significant discoveries were made in 22 different areas scattered along the entire length of the ridge. It is included on the National Register of Historic Places as well as the National Natural Landmark list.
History of discovery
The Fossil Cabin at Como Bluff, built in 1932 from broken dinosaur bones.
The discovery of dinosaurs at Como Bluff has been recounted numerous times, most notably by Schuchert and LeVene,[1] Shur,[2]Ostrom and McIntosh,[3] and Jaffe.[4] Most of the specimens were collected by men working for O.C. Marsh between 1877 and 1889, although some were collected by the Hubbel brothers for E.D. Cope between 1879 and 1880.[5] The American Museum of Natural History (AMNH) excavated in 1897 [1]-1898 [2], finding two partial skeletons of sauropods. A summary of the quarries and their contents is given below.
In later years, the American Museum of Natural History and Yale University jointly reopened Quarry 9, the Mammal Quarry, 1968–1970, finding only a few specimens.[6] More recently, Robert Bakker has done some collecting there with a variety of groups.
In addition to the major significance of dinosaur discoveries at Como Bluff, the site has also been the source of significant early mammal fossils. In early 1878, Marsh was ecstatic to find that one of his men had uncovered a fossil from a Jurassic mammal. Within a year, the historic Quarry 9 at Como was discovered, producing an astounding 250 specimens, which increased the knowledge of Jurassic mammals exponentially.[7]
^Schuchert, C., and LeVene, C.M. 1940. O.C.Marsh, Pioneer in Paleontology. Yale University Press, New Haven.
^Shur, E. 1974. The Fossil Feud. Exposition Press, NY. 340p.
^Ostrom, J. H., and McIntosh, J.S. 1966. Marsh's Dinosaurs: The Collections from Como Bluff. Yale University Press, New Haven.
^Jaffe, M. 2000. The Gilded Dinosaur. Crown Publ., New York.
^McCarren, Mark J. The Scientific Contributions of Othniel Charles Marsh, pp 1, 8, 19-20, Peabody Museum of Natural History, Yale University, New Haven, Connecticut. ISBN0-912532-32-7.
^Prothero, D.R. 1981. New Jurassic mammals from Como Bluff, Wyoming, and the interrelationships of non-tribosphenic Theria. Bulletin of the American Museum of Natural History 167: 281:325
^McCarren, Mark J. The Scientific Contributions of Othniel Charles Marsh, pp 1, 7-8, 19-20, Peabody Museum of Natural History, Yale University, New Haven, Connecticut. ISBN0-912532-32-7.
^Carrano, M.T., and Velez-Juarbe, J. 2006. Paleoecology of the Quarry 9 vertebrate assemblage from Como Bluff, Wyoming (Morrison Formation, Late Jurassic). Palaeogeography, Palaeoclimatology, Palaeoecology 237:147-159.
^Foster, J.R. 2003. Paleoecological analysis of the vertebrate fauna of the Morrison Formation (Upper Jurassic), Rocky Mountain region, USA. New Mexico Museum of Natural History and Science 23:1-95.
