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Cambrian Stage 4

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Cambrian Stage 4
~514.5 – ~506.5 Ma
Chronology
−540 —
−535 —
−530 —
−525 —
−520 —
−515 —
−510 —
−505 —
−500 —
−495 —
−490 —
−485 —
 
 
 
 
 
 
 
Orsten Fauna
Archaeocyatha extinction
SSF diversification, first brachiopods & archaeocyatha
Dresbachian extinction
Subdivision of the Cambrian according to the ICS, as of 2024.[1]
Vertical axis scale: Millions of years ago
Etymology
Name formalityInformal
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionNot formally defined
Lower boundary definition candidatesFAD of the Trilobite Olenellus or Redlichia
Lower boundary GSSP candidate section(s)None
Lower GSSP ratifiedNot formally defined
Upper boundary definitionFAD of Oryctocephalus indicus.
Upper boundary GSSPWuliu-Zengjiayan, Guizhou, China
26°04′51″N 108°24′50″E / 26.0807°N 108.4138°E / 26.0807; 108.4138
Upper GSSP ratifiedJune 25, 2018[2]

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.[3] Both proposals will set the lower boundary close to 514.5 million years ago.[4] The upper boundary corresponds to the beginning of the Wuliuan.

Naming

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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.[5]

Biostratigraphy

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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.[6]

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.[7]

References

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  1. ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. December 2024. Retrieved October 23, 2025.
  2. ^ "The Trilobite Papers Twenty" (PDF). PaleoNet. August 2018. p. 28. Retrieved October 20, 2025.
  3. ^ 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.
  4. ^ "GSSP Table - Paleozoic Era". Archived from the original on 2023-10-08. Retrieved 2024-03-19.
  5. ^ "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.
  6. ^ 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.
  7. ^ 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.{{cite journal}}: CS1 maint: multiple names: authors list (link)
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