Cambrian Stage 4
Template:Short description Template:Infobox geologic timespan Cambrian Stage 4 is the still unnamed fourth stage of the Cambrian and the upper stage of Cambrian Series 2. It follows Cambrian Stage 3 and lies below the Wuliuan. The lower boundary has not been formally defined by the International Commission on Stratigraphy. One proposal is the first appearance of two trilobite genera, Olenellus or Redlichia. Another proposal is the first appearance of the trilobite species Arthricocephalus chauveaui.[1] Both proposals will set the lower boundary close to Expression error: Unexpected round operator million years ago.[2] The upper boundary corresponds to the beginning of the Wuliuan.
Naming
The International Commission on Stratigraphy has not named the fourth stage of the Cambrian yet. In the widely used Siberian nomenclature stage 4 would overlap with parts of the Botomian and Toyonian.[3]
Biostratigraphy
The beginning of Cambrian Stage 4 has been tentatively correlated with the base of the European Leonian faunal stage and the base of the South China Duyunian faunal stage.[4]
During Cambrian Stage 4, three families of trilobites were widely distributed: olenellids, redlichiids, and paradoxidids. At the Stage 4-Wuliuan boundary, the first major trilobite extinction, known as the Olenellid Biomere boundary, occurred. In particular, trilobites of the families Ollenellidae and Redlichiidae have been extinct in Laurentia and South China, respectively.[5]
References
Page Template:Reflist/styles.css has no content.
- ^ Page Module:Citation/CS1/styles.css has no content.Peng, S.C.; Babcock, L.E. (21 September 2011). "Continuing progress on chronostratigraphic subdivision of the Cambrian System" (PDF). Bulletin of Geosciences: 391–396. doi:10.3140/bull.geosci.1273. Archived from the original (PDF) on 2023-07-16.
- ^ Page Module:Citation/CS1/styles.css has no content."GSSP Table - Paleozoic Era". Archived from the original on 2023-10-08. Retrieved 2024-03-19.
- ^ Page Module:Citation/CS1/styles.css has no content."The 13th International Field Conference of the Cambrian Stage Subdivision Working Group" (PDF). Episodes. 31 (4): 440–441. Archived from the original (PDF) on 2014-11-05. Retrieved 2024-04-03.
- ^ Page Module:Citation/CS1/styles.css has no content.Yuan, Jinliang; Ng, Tin-Wai (2014). "Tentative correlation of the Duyunian (Cambrian Series 2, Stage 4) and the Taijiangian (Cambrian Series 3, Stage 5) between South China and the Mediterranean region". GFF. 136 (1/2). Geological Society of Sweden: 314–319. Bibcode:2014GFF...136..314Y. doi:10.1080/11035897.2014.898331. S2CID 129488362.
- ^ Page Module:Citation/CS1/styles.css has no content.Jih-Pai Lin, Frederick A. Sundberg, Ganqing Jiang, Isabel P. Montañez, Thomas Wotte (22 November 2019). "Chemostratigraphic correlations across the first major trilobite extinction and faunal turnovers between Laurentia and South China". Scientific Reports. 9 (1): 17392. Bibcode:2019NatSR...917392L. doi:10.1038/s41598-019-53685-2. PMC 6874646. PMID 31758094.
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External links
- Page Module:Citation/CS1/styles.css has no content."ISCS Working Groups: Working Group on the Stage 4 GSSP". International Subcommission on Cambrian Stratigraphy. Archived from the original on 2023-09-26.
- Page Module:Citation/CS1/styles.css has no content."GSSP Table - Paleozoic Era". Archived from the original on 2023-10-08.
