Furongian

The Furongian is the fourth and final epoch and series of the Cambrian. It lasted from 497 to 485.4 million years ago. It succeeds the Miaolingian series of the Cambrian and precedes the Lower Ordovician Tremadocian Stage. It is subdivided into three stages: the Paibian, Jiangshanian and the unnamed 10th stage of the Cambrian.^[4]

Furongian
~497 – 485.4 ± 1.9 Ma PreꞒ Ꞓ O S D C P T J K Pg N
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	2003
Former name(s)	Cambrian Series 4
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Epoch
Stratigraphic unit	Series
First proposed by	Shanchi et al., 2002
Time span formality	Formal
Lower boundary definition	FAD of the Trilobite Glyptagnostus reticulatus
Lower boundary GSSP	Paibi section, Paibi, Hunan, China 28°23′22″N 109°31′33″E / 28.3895°N 109.5257°E / 28.3895; 109.5257
Lower GSSP ratified	2003^[2]
Upper boundary definition	FAD of the Conodont Iapetognathus fluctivagus.
Upper boundary GSSP	Greenpoint section, Green Point, Newfoundland, Canada 49°40′58″N 57°57′55″W / 49.6829°N 57.9653°W / 49.6829; -57.9653
Upper GSSP ratified	2000^[3]

Naming

The Furongian was also known as the Cambrian Series 4, and the name replaced the older term Upper Cambrian and equivalent to the local term Hunanian. The present name was ratified by the International Commission on Stratigraphy in 2003. Fúróng (芙蓉) means 'lotus' in Mandarin and refers to Hunan which is known as the "lotus state".^[5]

Definition

The lower boundary is defined in the same way as the GSSP of the Paibian Stage. Both begin with the first appearance of the trilobite Glyptagnostus reticulatus around 497 million years ago.^[6] The upper boundary is the lower boundary and GSSP of the Tremadocian Stage which is the first appearance of the conodont Iapetognathus fluctivagus around 485.4 million years ago.^[7]

Subdivisions

The following table shows the subdivisions of the Furongian series/epoch:^[4]

Series	Stage	Age (Ma)
Lower Ordovician
	Floian	477.7
	Tremadocian	485.4
Furongian
	Stage 10	489.5
	Jiangshanian	494
	Paibian	497
Series 3
	Guzhangian	500.5
	Drumian	504.5
	Wuliuan	509

Biostratigraphy

The base of two of three stages of the Furongian are defined as the first appearance of a trilobite. The base of the Paibian is the first appearance of Glyptagnostus reticulatus and the base of the Jiangshanian is the first appearance of Agnostotes orientalis.^[5][8] The still unnamed Cambrian Stage 10 might be defined as the first appearance of Lotagnostus americanus or the conodont Eoconodontus notchpeakensis.^[9]

The Furongian can be divided into a number of trilobite zones:

Series	Stage	Trilobite zone	Trilobite GSSP
Furongian	Stage 10	Saukia zone (upper part), Eurekia apopsis zone, Tangshanaspis Zone, Parakoldinioidia zone, Symphysurina zone^[9]	Lotagnostus americanus (undecided)
	Jiangshanian	Ellipsocephaloides zone, Saukia zone (lower part)^[9]	Agnostotes orientalis
	Paibian	? (?)	Glyptagnostus reticulatus
		Cedaria

References

1. "Chart/Time Scale". stratigraphy.org. International Commission on Stratigraphy.
2. 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. doi:10.1080/00241160410002081. Retrieved 8 December 2020.
3. Cooper, Roger; Nowlan, Godfrey; Williams, S. H. (March 2001). "Global Stratotype Section and Point for base of the Ordovician System" (PDF). Episodes. 24 (1): 19–28. doi:10.18814/epiiugs/2001/v24i1/005. Retrieved 6 December 2020.
4. "GSSP Table - Paleozoic Era". Geologic Timescale Foundation. Retrieved 17 November 2012.
5. Peng, Shanchi; Babcock, Loren; Robison, Richard; Lin, Huanling; Rees, Margaret; Saltzman, Matthew (30 November 2004). "Global Standard Stratotype-section and Point (GSSP) of the Furongian Series and Paibian Stage (Cambrian)" (PDF). Lethaia. 37 (4): 365–379. doi:10.1080/00241160410002081. Retrieved 14 September 2012.
6. . Archived from the original on 4 March 2016. Retrieved 12 November 2012.
7. . Archived from the original on 3 March 2016. Retrieved 17 November 2012.
8. "GSSP for Jiangshanian". Retrieved 12 November 2012.
9. Landing, E.; Westrop, S.R.; Adrain, J.M. (19 September 2011). "The Lawsonian Stage - the Eoconodontus notchpeakensis FAD and HERB carbon isotope excursion define a globally correlatable terminal Cambrian stage". Bulletin of Geosciences: 621–640. doi:10.3140/bull.geosci.1251.