Sundance Formation

From Wikipedia, the free encyclopedia
Jump to: navigation, search


Sundance Formation
Stratigraphic range: Upper Jurassic
Type sedimentary
Underlies Morrison Formation
Overlies Chugwater Formation
Primary limestone
Other shale, sandstone
Region Western North America
Country United States

The Sundance Formation is a western North American sequence of Upper Jurassic age[1] marine shales, sandy shales, and sandstones.


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 Upper Triassic Chugwater Formation red beds.


The Sundance Formation is known for fossils of an extinct species of marine cephalopod, Belemnites densus.

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.[2]

Vertebrate paleofauna[edit]


Pterosaurs of the Sundance Formation
Taxa Presence Description Images


  1. P. stokesi[3]
  • Found in Wyoming at the Alcova/Grey Reef Reservoir, Seminoe Reservoir, and Bighorn Canyon National Recreation area.[3]
  1. Found in Wyoming, at the ichnospecies' type locality.[3]
  • Alcova/Grey Reef Reservoir and Seminoe Reservoir housed at University of Wyoming, Laramie.[3] Alcova/Grey Reef Reservoir specimens are also housed at Tate Museum, Casper College.[3]
  1. Specimens housed at University of Wyoming, Laramie.[3]

Invertebrate paleofauna[edit]


Belemnoids of the Sundance Formation
Taxa Presence Description Images


  1. B. densus


  1. ^ 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". PALAIOS. SEPM Society for Sedimentary Geology. 21 (5): 480–492. doi:10.2110/palo.2005.P05-062R. 
  2. ^ BLM−Bureau of Land Management, Wyoming Office: "Red Gulch Dinosaur Tracksite" website, info, maps, photo gallery, accessed 8.21.2015
  3. ^ a b c d e f g 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.

Jurassic Period
Lower/Early Jurassic Middle Jurassic Upper/Late Jurassic
Hettangian | Sinemurian
Pliensbachian | Toarcian
Aalenian | Bajocian
Bathonian | Callovian
Oxfordian | Kimmeridgian