Miaolingian

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]

Miaolingian
~509 – ~497 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Map of Earth as it appeared 500 million years ago during the Miaolingian epoch, Guzhangian age[citation needed]
Chronology
−540 — – −535 — – −530 — – −525 — – −520 — – −515 — – −510 — – −505 — – −500 — – −495 — – −490 — – −485 — – N ♇ P a l e o z o i c Ediacaran C a m b r i a n O T e r r e n e u v i a n S e r i e s 2 M i a o l i n g. F u r o n g. Early O Fortunian "Stage 2" "Stage 3" "Stage 4" Wuliuan Drumian Guzhangian Paibian Jiangshanian "Stage 10"               ← Orsten Fauna ← Burgess Shale ← Kaili biota ← Archaeocyatha extinction ← Emu Bay Shale ← Sirius Passet biota ← Chengjiang biota ← First Trilobites ← SSF diversification, first brachiopods & archaeocyatha ← First halkieriids, mollusсs, hyoliths SSF ← Baykonurian glaciation ← Dresbachian extinction   Major Glacial period Subdivision of the Cambrian according to the ICS, as of 2022.[1] Vertical axis scale: millions of years ago
Etymology
Name formality	Formal
Name ratified	2018[2]
Former name(s)	Cambrian Series 3
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Epoch
Stratigraphic unit	Series
Time span formality	Formal
Lower boundary definition	FAD of the Trilobite Oryctocephalus indicus.
Lower boundary GSSP	Wuliu-Zengjiayan, Guizhou, China 26°44.843′N 108°24.830′E
Lower GSSP ratified	2018[2]
Upper boundary definition	FAD of the Trilobite Glyptagnostus reticulatus
Upper boundary GSSP	Paibi section, Paibi, Hunan, China 28°23.37′N 109°31.54′E
Upper GSSP ratified	2003[3]

It is named after the Miaoling 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

The Ordian stage, which is use in Australian chronostratigraphical scale, was originally supposed to be the lowest stage of the Miaolingian, but may belong to upper Series 2. As of 2024, the base of the Ordian is not defined yet.^[8]

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.^[9] 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.^[10]

Paleontology

Benthic graptolites have reached a wide distribution in the Miaolingian. Encrusting colonies of the 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.^[11]

References

1. "Chart/Time Scale". stratigraphy.org. International Commission on Stratigraphy.
2. Yuanlong Zhao; Jinliang Yuan; Loren E. Babcock; Qingjun Guo; Jin Peng; Leiming Yin; Xinglian Yang; Shanchi Peng; Chunjiang Wang; Robert R. Gaines; Jorge Esteve; Tongsu Tai; Ruidong Yang; Yue Wang; Haijing Sun; Yuning Yang (June 2019). "Global Standard Stratotype-Section and Point (GSSP) for the conterminous base of the Miaolingian Series and Wuliuan Stage (Cambrian) at Balang, Jianhe, Guizhou, China" (PDF). Episodes. 42 (2): 165–184. doi:10.18814/epiiugs/2019/019013. Archived (PDF) from the original on 2022-03-04. Retrieved 19 March 2024.
3. Peng, S. C.; Babcock, L. E.; Robison, R. A.; Lin, H. L.; Rees, M. N.; Saltzman, M. R. (2004). "Global Standard Stratotype-Section and Point (GSSP) of the Furongian Series and Paibian Stage (Cambrian)". Lethaia. 37 (4): 365–379. Bibcode:2004Letha..37..365P. doi:10.1080/00241160410002081. Archived 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. "GSSP Table - Paleozoic Era". Archived from the original on 2023-10-08. Retrieved 2024-03-19.
6. Gozalo, Rodolfo; Álvarez, María Eugenia Dies; Vintaned, José Antonio Gámez; Zhuravlev, Andrey Yu.; Bauluz, Blanca; Subías, Ignacio; Chirivella Martorell, Juan B.; Mayoral, Eduardo; Gursky, Hans-Jürgen; Andrés, José Antonio; Liñán, Eladio (1 December 2011). "Proposal of a reference section and point for the Cambrian Series 2-3 boundary in the Mediterranean subprovince in Murero (NE Spain) and its intercontinental correlation". Geological Journal. 48 (2–3): 142–155. doi:10.1002/gj.1330. S2CID 129084517.
7. Arne Thorshøj Nielsen, Per Ahlberg (2019). "The Miaolingian, a new name for the 'Middle' Cambrian (Cambrian Series 3): identification of lower and upper boundaries in Baltoscandia". GFF. 141 (2): 162-173. Bibcode:2019GFF...141..162N. doi:10.1080/11035897.2019.1621374.
8. John R. Laurie, Peter D. Kruse, Glenn A. Brock, James D. Holmes, James B. Jago, Marissa J. Betts, John R. Paterson, Patrick M. Smith (April 2024). "The quest for an Australian Cambrian stage scale". Alcheringa: An Australasian Journal of Palaeontology: 1–20. doi:10.1080/03115518.2024.2327045.{{cite journal}}: CS1 maint: multiple names: authors list (link)
9. 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)
10. 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)
11. Jörg Maletz (8 December 2023). "Benthic graptolites (Graptolithina, Pterobranchia) in the Miaolingian (Cambrian Series 3)". Palaeobiodiversity and Palaeoenvironments. 104 (2): 259–274. doi:10.1007/s12549-023-00595-x.

External links

• "Combined Image for Wuliuan Stage: GSSP of the Miaolingian Series and Wuliuan Stage in the Wului-Zengjiayan Section, Guizhou, China". Geologic Timescale Foundation. Archived from the original on 2022-05-26.
• Yuanlong Zhao; Jinliang Yuan; Loren E. Babcock; Qingjun Guo; Jin Peng; Leiming Yin; Xinglian Yang; Shanchi Peng; Chunjiang Wang; Robert R. Gaines; Jorge Esteve; Tongsu Tai; Ruidong Yang; Yue Wang; Haijing Sun; Yuning Yang (June 2019). "Global Standard Stratotype-Section and Point (GSSP) for the conterminous base of the Miaolingian Series and Wuliuan Stage (Cambrian) at Balang, Jianhe, Guizhou, China" (PDF). Episodes. 42 (2): 165–184. doi:10.18814/epiiugs/2019/019013. Archived (PDF) from the original on 2022-03-04. Retrieved 19 March 2024.