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Key events in the Cambrian
-550 —
-540 —
-530 —
-520 —
-510 —
-500 —
-490 —
 
 
 
 
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Orsten Fauna
Archaeocyatha extinction
SSF diversification, first brachiopods & archaeocyatha
Treptichnus pedum trace
Large negative peak δ 13Ccarb excursion
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 / 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.

The GSSP is defined in the Drumian section (39°30′42″N 112°59′29″W / 39.5117°N 112.9915°W / 39.5117; -112.9915) in the Drum Mountains, Millard County, Utah, United States.[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]

PalaeontologyEdit

ArthropodsEdit

Arthropods of the Drumian
Taxa Presence Location Description Images
"Stage 3"-Guzhangian Burgess Shale, British Columbia, Canada; Yuanshan Formation, Chengjiang biota, China
"Stage 5"-Guzhangian Phyllopod Bed, Burgess Shale

DinocarididansEdit

Dinocarididans of the Drumian
Taxa Presence Location Description Images
"Stage 3"-Drumian Burgess Shale, Canada; China; Wheeler Shale, Utah & Pennsylvania, USA; and Emu Bay, Kangaroo Island, Australia
"Stage 5"-Guzhangian Burgess Shale
Fortunian-Guzhangian Phyllopod bed, Walcott Quarry, Burgess Shale, British Columbia, Canada; Koscierzyna borehole, Kashubia, Poland

ReferencesEdit

  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.[permanent dead link]
  2. ^ "GSSP for Drumian Stage". Retrieved 12 November 2012.