Uintan
| Uintan | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chronology | |||||||||||||
| |||||||||||||
| Formerly part of | Tertiary Period/System | ||||||||||||
| Etymology | |||||||||||||
| Name formality | Formal | ||||||||||||
| Usage information | |||||||||||||
| Celestial body | Earth | ||||||||||||
| Regional usage | Global (ICS) | ||||||||||||
| Time scale(s) used | ICS Time Scale | ||||||||||||
| Definition | |||||||||||||
| Chronological unit | Age | ||||||||||||
| Stratigraphic unit | Stage | ||||||||||||
| Time span formality | Formal | ||||||||||||
| Upper boundary definition candidates | Calcareous nannofossil near LAD of the Haptophyte Reticulofenestra reticulata | ||||||||||||
| Upper boundary GSSP candidate section(s) | Contessa highway section, Gubbio, Central Apennines, Italy | ||||||||||||
The Uintan North American Stage is the North American faunal stage, typically set from 46,3 to 40,1 million years before present.[3] The Uintan Stage is a key part of the North American Land Mammal Age. In the Uinta Basin, a thriving subtropical ecosystem was formed at around 46.0 million years ago. It falls within the Eocene epoch, preceded by the Bridgerian and followed by the Duchesnean NALMA stages.[4] The Uinta Formation is a key piece of this geologic stage. Mammalian sabretooths evolved and became dominant predators in the now-Western United States. These included Apataelurus, Diegoaelurus, and Machaeroides.[5][6]
Substages
[edit]
The Uintan is considered to be contained within the Lutetian sharing the upper boundary and contains the following substages:
- Late/Upper Uintan: Lower boundary source of the base of the Uintan (approximate).
- Early/Lower Uintan: Upper boundary source of the base of the Duchesnean (approximate)
References
[edit]- ↑ Zachos, James C.; Kump, Lee R. (May 2005). "Carbon cycle feedbacks and the initiation of Antarctic glaciation in the earliest Oligocene". Global and Planetary Change. 47 (1): 51–66. Bibcode:2005GPC....47...51Z. doi:10.1016/j.gloplacha.2005.01.001. Retrieved October 2, 2025.
- ↑ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. December 2024. Retrieved October 23, 2025.
- ↑ Hodnett, John-Paul M.; Welsh, Edward T.; Santucci, Vincent L.; Tweet, Justin S. (2022). "A Middle Eocene brontothere (Mammalia; Perissodactyla; Brontotheriidae) from Yellowstone National Park, Wyoming". FOSSIL RECORD 8. New Mexico Museum of Natural History and Science. p. 211.
- ↑ "GeoWhen Database - Uintan". timescalefoundation.org. Retrieved 2025-06-01.
- ↑ Zack, Shawn P. (2019-11-22). "The first North American Propterodon (Hyaenodonta: Hyaenodontidae), a new species from the late Uintan of Utah". PeerJ. 7 e8136. doi:10.7717/peerj.8136. hdl:10150/636415. ISSN 2167-8359. PMC 6876642.
- ↑ County~tom@tskelly.gardnerville.nv.us, Thomas S. Kelly~Natural History Museum of Los Angeles; History~pmurphey@sdnhm.org, Paul C. Murphey~San Diego Museum of Natural (2016-07-14). "Mammals from the earliest Uintan (middle Eocene) Turtle Bluff Member, Bridger Formation, southwestern Wyoming, Part 1: Primates and Rodentia". Palaeontologia Electronica. doi:10.26879/586. Retrieved 2025-06-01.
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