The Sundance Formation is a western North American sequence of Middle Jurassic to Upper Jurassic age[ 1] Dating from the Bathonian to the Oxfordian , around 168-157 Ma, It is up to 100 metres thick[ 2] and consists of marine shale , sandy shale, sandstone , and limestone deposited in the Sundance Sea , an inland sea that covered large parts of western North America during the Middle and early Late Jurassic.
Geology
The Sundance Formation underlies the western North American Morrison Formation , the most fertile source of dinosaur fossils in the Americas, and is separated by a disconformity from the underlying Middle Jurassic Gypsum Springs Formation .
Fossils
The Sundance Formation is known for fossils of an extinct species of marine cephalopod , the belemnite Pachyteuthis densus , as well as several extinct species of oyster , including Deltoideum , Liostrea , and Gryphaea nebrascensis . Other common invertebrates include crinoids, echinoids, gastropods, insects, ostracods, and foraminifera.[ 3]
Fossil dinosaur 'footprints' on an ancient ocean shoreline are preserved in the formation and protected at the Red Gulch Dinosaur Tracksite , located in the Bureau of Land Management Red Gulch/Alkali National Back Country Byway, near Shell in Big Horn County, Wyoming .[ 4]
Paleobiota
Vertebrates
Invertebrates
Fish
References
^ Jennings, Debra S.; Stephen T. Hasiotis (2006). "Taphonomic analysis of a dinosaur feeding site using Geographic Information Systems (GIS), Morrison Formation, Southern Bighorn Basin, Wyoming, USA" (PDF) . PALAIOS . 21 (5). SEPM Society for Sedimentary Geology: 480–492. doi :10.2110/palo.2005.P05-062R . S2CID 55369947 .
^ Syzdek, Joseph; Malone, David; Craddock, John (2019-08-01). "Detrital Zircon U-Pb Geochronology and Provenance of the Sundance Formation, Western Powder River Basin, Wyoming" . The Mountain Geologist . 56 (3): 295–317. doi :10.31582/rmag.mg.56.3.295 . ISSN 0027-254X . S2CID 210290670 .
^ Mcmullen, Sharon K.; Holland, Steven M.; O'keefe, F. Robin (June 2014). "The Occurrence of Vertebrate and Invertebrate Fossils in a Sequence Stratigraphic Context: The Jurassic Sundance Formation, Bighorn Basin, Wyoming, U.S.A." PALAIOS . 29 (6): 277–294. doi :10.2110/pal.2013.132 . ISSN 0883-1351 . S2CID 126843460 .
^ BLM−Bureau of Land Management, Wyoming Office: "Red Gulch Dinosaur Tracksite" website , info, maps, photo gallery, accessed 8.21.2015
^ a b Lockley, M.; Harris, J.D.; and Mitchell, L. 2008. "A global overview of pterosaur ichnology: tracksite distribution in space and time." Zitteliana . B28. p. 187-198. ISSN 1612-4138 .
^ W. R. O'Keete, F. R. and Wahl Current taxonomic status of the plesiosaur Pantosaurus striatus from the Upper Jurassic Sundance Formation, Wyoming , article on pages 37-47 of the complete issue, 2003, Paludicola, 4 (2) : 27-68. Paperback – January 1, 2003
^ Massare, Judy A.; Wahl, William R.; Ross, Mike; Connely, Melissa V. (January 2014). "Palaeoecology of the marine reptiles of the Redwater Shale Member of the Sundance Formation (Jurassic) of central Wyoming, USA" . Geological Magazine . 151 (1): 167–182. doi :10.1017/S0016756813000472 . ISSN 0016-7568 – via Geological Magazine.
44°15′24″N 105°40′57″W / 44.2568°N 105.6824°W / 44.2568; -105.6824
Cenozoic chronostratigraphy of Colorado
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Mesozoic chronostratigraphy of Colorado
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Paleozoic chronostratigraphy of Colorado
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Precambrian chronostratigraphy of Colorado
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