Drumian

EtymologyName formalityFormalName ratified2006Former name(s)Cambrian Stage 6Usage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitAgeStratigraphic unitStageFirst proposed byBabcock et al., 2006Time span formalityFormalLower boundary definitionFAD of the TrilobitePtychagnostus atavusLower boundary GSSPDrumian section, Wheeler Shale, Utah, U.S.A.
39°30′42″N112°59′29″W / 39.5117°N 112.9915°W / 39.5117; -112.9915Lower GSSP ratified2006Upper boundary definitionFAD of the TrilobiteLejopyge laevigataUpper boundary GSSPLuoyixi section, Luoyixi, Guzhang, Hunan, China
28°43′12″N109°57′53″E / 28.7200°N 109.9647°E / 28.7200; 109.9647Upper GSSP ratified2008

39°30′42″N112°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 trilobitePtychagnostus 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.