Early Jurassic

EtymologyChronostratigraphic nameLower JurassicGeochronological nameEarly JurassicName formalityFormalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitEpochStratigraphic unitSeriesTime span formalityFormalLower boundary definitionFAD of the AmmonitePsiloceras spelae tirolicum.Lower boundary GSSPKuhjoch section, Karwendel mountains, Northern Calcareous Alps, Austria
47°29′02″N11°31′50″E / 47.4839°N 11.5306°E / 47.4839; 11.5306Lower GSSP ratified2010Upper boundary definitionFAD of the Ammonites and Upper boundary GSSPFuentelsaz, Spain
41°10′15″N1°50′00″W / 41.1708°N 1.8333°W / 41.1708; -1.8333Upper GSSP ratified2000

The Early JurassicEpoch (in chronostratigraphy corresponding to the Lower JurassicSeries) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic–Jurassic extinction event, 201.3 Ma (million years ago), and ends at the start of the Middle Jurassic 174.7 ±0.8 Ma.

Certain rocks of marine origin of this age in Europe are called "Lias" and that name was used for the period, as well, in 19th-century geology. In southern Germany rocks of this age are called Black Jurassic.