Miaolingian

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Miaolingian
~509 – ~497 Ma
Chronology
Dresbachian extinction
Subdivision of the Cambrian according to the
Epoch
Stratigraphic unitSeries
Time span formalityFormal
Lower boundary definitionFAD of the Trilobite Oryctocephalus indicus.
Lower boundary GSSPWuliu-Zengjiayan, Guizhou, China
26°44.843′N 108°24.830′E / 26.747383°N 108.413833°E / 26.747383; 108.413833
Lower GSSP ratified2018[2]
Upper boundary definitionFAD of the Trilobite Glyptagnostus reticulatus
Upper boundary GSSPPaibi section, Paibi, Hunan, China
28°23.37′N 109°31.54′E / 28.38950°N 109.52567°E / 28.38950; 109.52567
Upper GSSP ratified2003[3]

The Miaolingian is the third Series of the Cambrian Period, and was formally named in 2018.[4] It lasted from about 509 to 497 million years ago and is divided in ascending order into 3 stages: the Wuliuan, Drumian, and Guzhangian. The Miaolingian is preceded by the unnamed Cambrian Series 2 and succeeded by the Furongian series.[5]

It is named after the Maioling Mountains in southeastern Guizhou Province, China.[2]

Definition

A number of proposals for fossils and type sections were made before it was formally ratified in 2018. The most promising fossil markers were seen to be the respective first appearances of either trilobite species Ovatoryctocara granulata or Oryctocephalus indicus,[6] which both have an age close to 509 million years ago.[5] After some deliberation, the FAD of Oryctocephalus indicus was chosen to be the lower boundary marker, and the GSSP was placed in the Kaili Formation, Wuliu-Zengjiayan, Guizhou, China.[2][7]

The Miaolingian-Furongian boundary has the same definition as the Paibian Stage. It is defined as the first appearance of Glyptagnostus reticulatus around 497 million years ago.[5]

Subdivision

The Miaolingian is subdivided into the following stages:[5]

Epoch / Series Age / Stage Age lower boundary (mya)
Furongian
Stage 10 489.5
Jiangshanian 494
Paibian 497
Miaolingian
Guzhangian 500.5
Drumian 504.5
Wuliuan 509
Series 2
Stage 4 514
Stage 3 521

Major events

At the Cambrian Series 2–Miaolingian 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.[8] The first O. indicus appear after this global extinction, and in areas where O. indicus fossils are absent, the Series 2–Miaolingian boundary is determined by chemostratigraphic data.[9]

Paleontology

Benthic

Rhabdopleuridae and erect growing branching colonies of the Dithecodendridae families evolved already at the beginning of the Miaolingian. The most common Wuliuan graptolite genus is Sphenoecium, whose robust colonies were found all over the world.[10]

References

  1. ^ "Chart/Time Scale". stratigraphy.org. International Commission on Stratigraphy.
  2. ^ (PDF) from the original on 2022-03-04. Retrieved 19 March 2024.
  3. from the original on 2023-07-21. Retrieved 19 March 2024.
  4. ^ "International Chronostratigraphic Chart (2018)" (PDF). Archived from the original (PDF) on 2018-09-07. Retrieved 2024-03-19.
  5. ^ a b c d "GSSP Table - Paleozoic Era". Archived from the original on 2023-10-08. Retrieved 2024-03-19.
  6. S2CID 129084517
    .
  7. .
  8. PMC 6874646.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  9. ^ Courtney Birksmith, Glenn A. Brock, Marissa J. Betts, James D. Holmes, Zhiliang Zhang (2023). "Chronostratigraphy of the Cambrian Series 2 -Miaolingian boundary, western Stansbury Basin, South Australia". Conference: Palaeo Down Under 3 at Perth, Western Australia.{{cite web}}: CS1 maint: multiple names: authors list (link)
  10. .

External links