File:Didymoceras cheyennense (fossil ammonite) (Pierre Shale, Upper Cretaceous; Custer County, South Dakota, USA) (33938339953).jpg
Original file (1,873 × 3,276 pixels, file size: 3.61 MB, MIME type: image/jpeg)
|
This is a file from the Wikimedia Commons. The description on its description page there is shown below.
Commons is a freely licensed media file repository. You can help. |
_(Pierre_Shale,_Upper_Cretaceous;_Custer_County,_South_Dakota,_USA)_(33938339953).jpg){kind=small}
Summary
| Description |
Didymoceras cheyennense (Meek & Hayden, 1856) - fossil ammonite from the Cretaceous of South Dakota, USA. Ammonites are common & conspicuous fossils in Mesozoic marine sedimentary rocks. Ammonites are an extinct group of cephalopods - they’re basically squids in coiled shells. The living chambered nautilus also has a squid-in-a-coiled-shell body plan, but ammonites are a different group. Ammonites get their name from the coiled shell shape being reminiscent of a ram’s horn. The ancient Egyptian god Amun (“Ammon” in Greek) was often depicted with a ram’s head & horns. Pliny’s Natural History, book 37, written in the 70s A.D., refers to these fossils as “Hammonis cornu” (the horn of Ammon), and mentions that people living in northeastern Africa perceived them as sacred. Pliny also indicates that ammonites were often pyritized. Ammonites typically have a planispirally coiled, calcareous shell. The fossil shown above has a bizarre and irregularly shaped shell. Such examples are called heteromorph ammonites. Classification: Animalia, Mollusca, Cephalopoda, Ammonoidea, Ancyloceratina, Nostoceratidae Stratigraphy: Pierre Shale, Upper Cretaceous Locality: unrecorded/undisclosed site in Custer County, southwestern South Dakota, USA See info. at: <a href="https://en.wikipedia.org/wiki/Didymoceras" rel="nofollow">en.wikipedia.org/wiki/Didymoceras</a> and <a href="https://en.wikipedia.org/wiki/Ancyloceratina" rel="nofollow">en.wikipedia.org/wiki/Ancyloceratina</a> |
| Date | |
| Source | Didymoceras cheyennense (fossil ammonite) (Pierre Shale, Upper Cretaceous; Custer County, South Dakota, USA) |
| Author | James St. John |
Licensing
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
|
This image was originally posted to Flickr by James St. John at https://flickr.com/photos/47445767@N05/33938339953 (archive). It was reviewed on 1 December 2019 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 09:02, 1 December 2019 | | 1,873 × 3,276 (3.61 MB) | Ser Amantio di Nicolao | Transferred from Flickr via #flickr2commons |
File usage
The following 2 pages use this file:
Global file usage
The following other wikis use this file:
- Usage on www.wikidata.org
_(Pierre_Shale,_Upper_Cretaceous;_Custer_County,_South_Dakota,_USA)_(33938339953).jpg){kind=link}