Explore relationships

Early Devonian

Subdivision of the Devonian according to the ICS, as of 2024Vertical axis scale: Millions of years agoEtymologyChronostratigraphic nameLower DevonianGeochronological nameEarly DevonianName formalityFormalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitEpochStratigraphic unitSeriesTime span formalityFormalLower boundary definitionFAD of the graptoliteMonograptus uniformisLower boundary GSSPKlonk, Czech Republic49°51′18″N13°47′31″E / 49.8550°N 13.7920°E / 49.8550; 13.7920Lower GSSP ratified1972Upper boundary definitionFAD of the conodontPolygnathus costatus partitusUpper boundary GSSP, , Eifel, Germany50°08′59″N6°28′18″E / 50.1496°N 6.4716°E / 50.1496; 6.4716Upper GSSP ratified1985The Early Devonian is the first of three epochs comprising the Devonian period, corresponding to the Lower Devonianseries.

Use + to expand a branch. Click a topic name to open its summary.