The Germanic Trias Supergroup is a lithostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of western and central Europe (north of the Alps) and the North Sea. Almost all of the Germanic Trias was deposited during the Triassic period and consists of three clearly different units: Buntsandstein, Muschelkalk and Keuper, that gave the period its name (Triassic means "threefold"). In the past the names of these three units were also used as units in the geologic timescale, but in modern literature they only have a lithostratigraphic meaning.