Wuliuan

EtymologyName formalityFormalName ratifiedJune 25, 2018Former name(s)Cambrian Stage 5Usage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitAgeStratigraphic unitStageFirst proposed byZhao et al., 2018Time span formalityFormalLower boundary definitionFAD of Oryctocephalus indicus.Lower boundary GSSP, Guizhou, China
26°04′51″N108°24′50″E / 26.0807°N 108.4138°E / 26.0807; 108.4138Lower GSSP ratifiedJune 25, 2018Upper boundary definitionFAD of the TrilobitePtychagnostus atavusUpper boundary GSSPDrumian section, Wheeler Shale, Utah, U.S.A.
39°30′42″N112°59′29″W / 39.5117°N 112.9915°W / 39.5117; -112.9915Upper GSSP ratified2006

The Wuliuanstage is the fifth stage of the Cambrian, and the first stage of the Miaolingian Series of the Cambrian. It was formally defined by the International Commission on Stratigraphy in 2018. Its base is defined by the first appearance of the trilobite species Oryctocephalus indicus; it ends with the beginning of the Drumian Stage, marked by the first appearance of the trilobite Ptychagnostus atavus around 504.5 million years ago.

The 'golden spike' that formally defines the base of the age is driven into the Wuliu-Zengjiayan (乌溜-曾家崖) section of the Kaili formation, near Balang Village in the Miaoling Mountains, Guizhou, China.