Anisian

EtymologyName formalityFormalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitAgeStratigraphic unitStageTime span formalityFormalLower boundary definitionNot formally definedLower boundary definition candidates

• FAD of the ConodontChiosella timorensis
• Base of magnetic zone MT1n

Lower boundary GSSP candidate section(s)

• , Northern Dobruja, Romania
• Guandao, Guizhou, China

Upper boundary definitionFAD of the AmmoniteUpper boundary GSSPBagolino, Lombardian pre-Alps, Italy
45°49′09″N10°28′16″E / 45.8193°N 10.4710°E / 45.8193; 10.4710Upper GSSP ratified2005

In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassicseries or epoch and lasted from 247 million years ago until 241.464 million years ago. The Anisian Age succeeds the Olenekian Age (part of the Lower Triassic Epoch) and precedes the Ladinian Age.