Drumian

Key events in the Cambrian

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Ediacaran

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Ordovician

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Fortunian

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"Stage 3"

"Stage 4"

"Stage 5"

Drumian

Guzhangian

Paibian

Jiangshanian

"Stage 10"

 

 

 

 

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Baykonur
glaciation

Baykonur
glaciation

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Orsten Fauna

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Burgess Shale

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Kaili biota

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Archaeocyatha extinction

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Emu Bay Shale

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Sirius Passet biota

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Chengjiang biota

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First Trilobites

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SSF diversification, first brachiopods & archaeocyatha

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First halkieriids, mollusсs, hyoliths SSF

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Treptichnus pedum trace
Large negative peak δ 13C_carb excursion

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First Cloudina & Namacalathus mineral tubular fossils

Stratigraphic scale of the ICS subdivisions and Precambrian/Cambrian boundary.

Coordinates: 39°30′42″N 112°59′29″W / 39.5117°N 112.9915°W The Drumian is a stage of 3rd series of the Cambrian. It succeeds still unnamed 5th stage of the Cambrian 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.

The GSSP is defined in the Drumian section (39°30′42″N 112°59′29″W / 39.5117°N 112.9915°W) in the Drum Mountains, Millard County, Utah, USA.^[1] The stage was also named after the Drum Mountains. The section is an outcrop of the Wheeler Formation, a succession of calcareous shales. The precise base of the Drumian is a laminated limestone 62 m (203 ft) above the base of the Wheeler Formation.^[2]

References

1. Babcock, Loren E.; Richard A. Robison; Margaret N. Rees; Shanchi Peng; Matthew R. Saltzman (2007). "The Global boundary Stratotype Section and Point (GSSP) of the Drumian Stage (Cambrian) in the Drum Mountains, Utah, USA" (PDF). Episodes 30 (2): 85–95. Retrieved 14 September 2012.
2. "GSSP for Drumian Stage". Retrieved 12 November 2012.

Preceded by Proterozoic Eon	Phanerozoic Eon
	Paleozoic Era						Mesozoic Era			Cenozoic Era
	Cambrian	Ordovician	Silurian	Devonian	Carboniferous	Permian	Triassic	Jurassic	Cretaceous	Paleogene	Neogene	4ry