Katian
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The Katian is the second stage of the Upper Ordovician. It is preceded by the Sandbian and succeeded by the Hirnantian stage. The Katian began 453 million years ago and lasted for about 7.8 million years until the beginning of the Hirnantian 445.2 million years ago.[5] During the Katian climate cooled which started the Late Ordovician glaciation
Naming
The name Katian is derived from Katy Lake (Atoka County, Oklahoma, United States).[6]
GSSP
The GSSP of the Katian stage is the Black Knob Ridge Section in southeastern Oklahoma (United States). It is an outcrop of the Womble Shale and the Bigfork Chert, the latter containing the lower boundary of the Katian. The lower boundary is defined as the first appearance datum of the graptolite species Diplacanthograptus caudatus. This horizon is 4.0 m above the base of the Bigfork Chert.[7][8]
Palaeontology
Molluscs
Cephalopods
Endocerids
| Endocerids of the Sandbian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Dapingian-Homerian | ||||
| Dapingian-Hirnantian | ||||
References
- ^ Wellman, C.H.; Gray, J. (2000). "The microfossil record of early land plants". Phil. Trans. R. Soc. B. 355 (1398): 717–732. doi:10.1098/rstb.2000.0612. PMC 1692785. PMID 10905606.
- ^ Korochantseva, Ekaterina; Trieloff, Mario; Lorenz, Cyrill; Buykin, Alexey; Ivanova, Marina; Schwarz, Winfried; Hopp, Jens; Jessberger, Elmar (2007). "L-chondrite asteroid breakup tied to Ordovician meteorite shower by multiple isochron 40 Ar- 39 Ar dating". Meteoritics & Planetary Science. 42 (1): 113–130. Bibcode:2007M&PS...42..113K. doi:10.1111/j.1945-5100.2007.tb00221.x.
- ^ Lindskog, A.; Costa, M. M.; Rasmussen, C.M.Ø.; Connelly, J. N.; Eriksson, M. E. (2017-01-24). "Refined Ordovician timescale reveals no link between asteroid breakup and biodiversification". Nature Communications. 8: 14066. doi:10.1038/ncomms14066. ISSN 2041-1723. PMC 5286199. PMID 28117834.
It has been suggested that the Middle Ordovician meteorite bombardment played a crucial role in the Great Ordovician Biodiversification Event, but this study shows that the two phenomena were unrelated
- ^ "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
- ^ "GSSP Table - Paleozoic Era". Geologic Timescale Foundation. Retrieved 2 December 2012.
- ^ Bergström, Stig; Finney, Stanley; Xu, Chen; Goldman, Daniel; Leslie, Stephen (31 August 2006). "Three new Ordovician global stage names". Lethaia. 39 (3): 287–288. doi:10.1080/00241160600847439.
- ^ Goldman, Daniel; Stephen A. Leslie; Jaak Nõlvak; Seth Young; Stig M. Bergström; Warren D. Huff (2007). "The Global Stratotype Section and Point (GSSP) for the base of the Katian Stage of the Upper Ordovician Series at Black Knob Ridge, Southeastern Oklahoma, USA" (PDF). Episodes. 30 (4): 258–270. Retrieved 20 September 2012.
- ^ "GSSP for Katian Stage". Geologic Timescale Foundation. Retrieved 2 December 2012.
34°25′50″N 96°04′29″W / 34.4305°N 96.0746°W
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