Cambrian Series 2

EtymologyName formalityInformalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitEpochStratigraphic unitSeriesTime span formalityFormalLower boundary definitionNot formally definedLower boundary definition candidatesFAD of TrilobitesLower boundary GSSP candidate section(s)NoneLower GSSP ratifiedNot formally definedUpper boundary definitionFAD of Oryctocephalus indicus.Upper boundary GSSP, Guizhou, China
26°04′51″N108°24′50″E / 26.0807°N 108.4138°E / 26.0807; 108.4138Upper GSSP ratifiedJune 25, 2018

Cambrian Series 2 or Mid-Early Cambrian is the unnamed 2nd series of the Cambrian. It lies above the Terreneuvian series and below the Miaolingian. Series 2 has not been formally defined by the International Commission on Stratigraphy, lacking a precise lower boundary and subdivision into stages. The proposed lower boundary is the first appearance of trilobites which is estimated to be around 521 million years ago.