The Ripley Formation is a geological formation in North America found in the U.S. states of Alabama, Georgia, Mississippi, Missouri,[1] and Tennessee. The lithology is consistent throughout the layer. It consists mainly of glauconitic sandstone. It was formed by sediments deposited during the Maastrichtian stage of the Late Cretaceous. It is a unit of the Selma Group and consists of the Cusseta Sand Member, McNairy Sand Member and an unnamed lower member.[2] It has not been extensively studied by vertebrate paleontologists, due to a lack of accessible exposures. However, fossils have been unearthed including crocodile, hadrosaur, nodosaur, tyrannosaur, ornithomimid, dromaeosaur, and mosasaur remains have been recovered from the Ripley Formation.[2]
| Ripley Formation | |
|---|---|
| Stratigraphic range: Upper Cretaceous | |
 Rockground exposed in the Ripley Formation near Greenville, Alabama. | |
| Type | Geological formation |
| Unit of | Selma Group |
| Sub-units | Cusseta Sand Member, McNairy Sand Member (Chronister dinosaur site) |
| Underlies | Prairie Bluff Chalk Formation |
| Overlies | Demopolis Chalk Formation |
| Thickness | 40 m (130 ft) to 175 m (574 ft) |
| Lithology | |
| Primary | Glauconitic sandstone |
| Other | Micaceous chalk |
| Location | |
| Region | Alabama, Georgia, Mississippi, Missouri, Tennessee |
| Country | United States |
| Type section | |
| Named for | Ripley, Mississippi |
Paleofauna
edit- Hypsibema missouriensis (hadrosaurid) – "Caudal vertebrae, fragmentary dentary and predentary."[3]
- cf. Gryposaurus sp.[4]
- Nodosauridae sp.[5]
- Tyrannosauroidea sp.[6][7][8]
- cf. Albertosaurus sp.[9]
- Dromaeosauridae sp.[7]
- Possible Ornithomimidae indet.[7]
- Eothoracosaurus mississippiensis[10]
- Thoracosaurus neocesariensis[11]
- Leidyosuchus sp.
- Adocus punctatus
- Naomichelys speciosa
- Trionyx sp.[4]
- Habrosaurus sp.
- Amiidae sp.
- Lepisosteus sp.
- Platacodon nanus
See also
edit
References
edit- ^ "Hypsibema missouriensis". DinoData. 2011. Archived from the original on September 13, 2011. Retrieved January 12, 2011.
- ^ a b Kiernan, Caitlin R. (2002). "Stratigraphic distribution and habitat segregation of mosasaurs in the Upper Cretaceous of western and central Alabama, with an historical review of Alabama mosasaur discoveries". Journal of Vertebrate Paleontology. 22 (1): 91–103. doi:10.1671/0272-4634(2002)022[0091:SDAHSO]2.0.CO;2. S2CID 130280406.
- ^ "Table 20.1," in Weishampel, et al. (2004). Page 443.
- ^ a b Parris, David. "CHRONISTER SITE INVESTIGATIONS: NEW INFORMATION ON THE CRETACEOUS OF MISSOURI". Retrieved 6 October 2006.
- ^ Bruns, Michael E. "NEW APPALACHIAN ARMORED DINOSAUR MATERIAL (NODOSAURIDAE, ANKYLOSAURIA) FROM THE MAASTRICHTIAN RIPLEY FORMATION OF ALABAMA". The Geological Society of America. Retrieved 1 April 2016.
- ^ Powers, Marc (February 19, 2004). "A bone to pick for Missouri". Southeast Missourian. Southeast Missourian. Archived from the original on November 18, 2015. Retrieved January 12, 2011.
- ^ a b c Fix, Michael F.; Darrough, Guy (2004). "Dinosauria and associated vertebrate fauna of the Late Cretaceous Chronister site of southeast Missouri". Abstracts with Programs. 36 (3). Geological Society of America: 14. Archived from the original on 2012-03-31. Retrieved 2016-08-28.
- ^ Holloway, Brad (January 31, 2005). "Rock of ages – Museum reveals fossil find in Bollinger County". Southeast Missourian. Southeast Missourian. Retrieved January 14, 2011.
- ^ "Missouri Dinosaur - Chronister Vertebrate Site - Bruce Sinchcomb". www.lakeneosho.org. Retrieved 2021-12-12.
- ^ Brochu, Christopher A. (2004-09-10). "A new Late Cretaceous gavialoid crocodylian from eastern North America and the phylogenetic relationships of thoracosaurs". Journal of Vertebrate Paleontology. 24 (3): 610–633. doi:10.1671/0272-4634(2004)024[0610:anlcgc]2.0.co;2. ISSN 0272-4634. S2CID 131176447.
- ^ Kenneth., Carpenter (1983). Thoracosaurus neocesariensis (De Kay, 1842) (Crocodylia: Crocodylidae) from the Late Cretaceous Ripley Formation of Mississippi. [s.n.] OCLC 895629547.