Drumian

Drumian
Drumian
Chronology
←	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. ; Vertical axis scale: millions of years ago
Etymology
Name formality	Formal
Name ratified	2006
Former name(s)	Cambrian Stage 6
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Age
Stratigraphic unit	Stage
First proposed by	Babcock et al., 2006
Time span formality	Formal
Lower boundary definition	FAD of the Trilobite Ptychagnostus atavus
Lower boundary GSSP	Drumian section, Wheeler Shale, Utah, U.S.A.; 39°30′42″N 112°59′29″W / 39.5117°N 112.9915°W
Lower GSSP ratified	2006
Upper boundary definition	FAD of the Trilobite Lejopyge laevigata
Upper boundary GSSP	Luoyixi section, Luoyixi, Guzhang, Hunan, China; 28°43′12″N 109°57′53″E / 28.7200°N 109.9647°E
Upper GSSP ratified	2008

39°30′42″N 112°59′29″W / 39.5117°N 112.9915°W / 39.5117; -112.9915 The Drumian is a stage of the Miaolingian Series of the Cambrian. It succeeds the Wuliuan and precedes the Guzhangian. The base is defined as the first appearance of the trilobite Ptychagnostus atavus around 504.5 million years ago. The top is defined as the first appearance of another trilobite Lejopyge laevigata around 500.5 million years ago.

^ "Chart/Time Scale". stratigraphy.org. International Commission on Stratigraphy.
^ ^a ^b Babcock, Loren; Robison, Richard; Rees, Margaret; Peng, Shanchi; Saltzman, Matthew (June 2007). "The Global boundary Stratotype Section and Point (GSSP) of the Drumian Stage (Cambrian) in the Drum Mountains, Utah, USA" (PDF). Episodes. 30 (2): 85–89. doi:10.18814/epiiugs/2007/v30i2/003. Archived (PDF) from the original on 2024-03-28. Retrieved 2024-04-03.
^ Babcock, Loren; Robinson, Richard; Rees, Margaret; Shanchi, Peng; Saltzman, Matthew. "PROPOSED GLOBAL STANDARD STRATOTYPE-SECTION AND POINT FOR THE DRUMIAN STAGE (CAMBRIAN)" (PDF). International Subcommission on Cambrian Stratigraphy. International Subcommission on Cambrian Stratigraphy. Archived (PDF) from the original on 2020-07-09. Retrieved 2024-04-03.
^ Peng, Shanchi; Babcock, Loren; Zuo, Jingxun; Lin, Huanling; Zhu, Xuejian; Yang, Xianfeng; Robison, Richard; Qi, Yuping; Bagnoli, Gabriella; Chen, Yong’an (March 2009). "The Global Boundary Stratotype Section and Point (GSSP) of the Guzhangian Stage (Cambrian) in the Wuling Mountains, Northwestern Hunan, China". Episodes. 32 (1): 41–55. doi:10.18814/epiiugs/2009/v32i1/006. Retrieved 2024-04-03.