Dapingian

The Dapingian is the third stage of the Ordovician and the first stage of the Middle Ordovician. It is preceded by the Floian and succeeded by the Darriwilian. The top of the Floian is defined as the first appearance of the conodont species Baltoniodus triangularis which happened about 470 million years ago. The Dapingian lasted for about 2.7 million years until about 467.3 million years ago.^[3]

Naming

The Dapingian is named after a village that lies nearby the Dapingian GSSP (Huanghuachang section, in Huanghuachang) where there is also an outcrop of similar rocks, the "Chenjiahe section" (formerly "Daping section") in Chenjiahe. The name was proposed in 2005.^[4]

GSSP

Huanghuachang section

Map of China showing the GSSP location.

The GSSP of the Dapingian is the Huanghuachang section (30°51′38″N 111°22′26″E / 30.8605°N 111.3740°E / 30.8605; 111.3740), in Huanghuachang, Yichang, China. It is an outcrop of the Dawan Formation. The lower boundary is defined as the first appearance of the conodont species Baltoniodus triangularis in the type section. Radiometric dating has constrained the Floian-Dapingian boundary at 470 million years ago.^[3] The exact boundary lies 10.57 m above the base of Dawan Formation.^[4]^[5]

Regional stages

The Dapingian overlaps with the Arenig, a geologic stage used in England.^[2]

Palaeontology

Agnathans

Agnathans of the Dapingian
Taxa	Presence	Location	Description	Images
Sacabambaspis	Dapingian-Sandbian	Sacabamba, Cochabamba Department, Bolivia; Horn Creek Siltstone, Australia; Argentina; Oman

Cephalopods

Endocerids

Endocerids of the Dapingian
Taxa	Presence	Location	Description	Images
Cameroceras	Dapingian-Homerian
Endoceras	Dapingian-Hirnantian
Meniscoceras	Dapingian-Darriwilian	Chazy Reef Formation, New York, USA
Najaceras	Dapingian-Darriwilian	West Spring Creek, Oil Creek Limestone, Oklahoma
Nanno	Dapingian-Darriwilian
Proterovaginoceras	Tremadocian-Darriwilian

References

↑ Wellman, C.H.; Gray, J. (2000). "The microfossil record of early land plants". Phil. Trans. R. Soc. B. 355 (1398): 717&ndash, 732. doi:10.1098/rstb.2000.0612. PMC 1692785. PMID 10905606.
1 2 Gradstein, F. M., ed. (2012). The Geologic Time Scale 2012. Elsevier Science Ltd. p. 504. ISBN 978-0444594259.
1 2 "GSSP Table - Paleozoic Era". Geologic TimeScale Foundation. Retrieved 24 November 2012. Note: there is an apparent typo in the article referenced; they give the coordinates as "a latitude of 30°51’37.8"N and a longitude of 110°22’26.5"E", but their map and location description better corresponds to 30°51’37.8"N 111°22’26.5"E.
1 2 Wang, Xiaofeng; Stouge, Svend; Erdtmann, Bernd-D.; Chen, Xiaohong; Li, Zhihong; Wang, Chuanshang; Zeng, Qingluan; Zhou, Zhiqiang; Chen, Huiming (2005). "A proposed GSSP for the base of the Middle Ordovician Series: the Huanghuachang section, Yichang, China" (PDF). Episodes. 28 (2): 105–117. Retrieved 4 June 2013.
↑ Wang, Xiaofeng; Stouge, Svend; Xiaohong, Chen; Zhihong, Li; Chuanshang, Wang; Finney, Stan C.; Qingluan, Zeng; Zhiqiang, Zhou; Huiming, Chen; Erdtmann, Bernd-D. (2009). "The Global Stratotype Section and Point for the base of the Middle Ordovician Series and the Third Stage (Dapingian)" (PDF). Episodes. 32 (2): 96–113. Retrieved 4 June 2013.

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[Wellman2000-1] Wellman, C.H.; Gray, J. (2000). "The microfossil record of early land plants". Phil. Trans. R. Soc. B. 355 (1398): 717&ndash, 732. doi:10.1098/rstb.2000.0612. PMC 1692785. PMID 10905606.

[The_Geologic_Time_Scale_2012-2] 1 2 Gradstein, F. M., ed. (2012). The Geologic Time Scale 2012. Elsevier Science Ltd. p. 504. ISBN 978-0444594259.

[GSSP_Table_-_Paleozoic_Era-3] 1 2 "GSSP Table - Paleozoic Era". Geologic TimeScale Foundation. Retrieved 24 November 2012. Note: there is an apparent typo in the article referenced; they give the coordinates as "a latitude of 30°51’37.8"N and a longitude of 110°22’26.5"E", but their map and location description better corresponds to 30°51’37.8"N 111°22’26.5"E.

[Wang_2005-4] 1 2 Wang, Xiaofeng; Stouge, Svend; Erdtmann, Bernd-D.; Chen, Xiaohong; Li, Zhihong; Wang, Chuanshang; Zeng, Qingluan; Zhou, Zhiqiang; Chen, Huiming (2005). "A proposed GSSP for the base of the Middle Ordovician Series: the Huanghuachang section, Yichang, China" (PDF). Episodes. 28 (2): 105–117. Retrieved 4 June 2013.

[Wang_2009-5] Wang, Xiaofeng; Stouge, Svend; Xiaohong, Chen; Zhihong, Li; Chuanshang, Wang; Finney, Stan C.; Qingluan, Zeng; Zhiqiang, Zhou; Huiming, Chen; Erdtmann, Bernd-D. (2009). "The Global Stratotype Section and Point for the base of the Middle Ordovician Series and the Third Stage (Dapingian)" (PDF). Episodes. 32 (2): 96–113. Retrieved 4 June 2013.