concept

Conservation deposit (Konservat-Lagerstätte)

A rare rock unit where soft tissue - muscle, gut, eyes, feathers, gills - survives instead of decaying away, usually because bodies were buried extremely fast into anoxic conditions with no scavengers. The paleontologist Adolf Seilacher distinguished these from concentration deposits, where only bones and shells pile up. The Burgess Shale, Solnhofen limestone, the Jehol beds and Messel Pit are conservation deposits - and each one works through a specific, identifiable mechanism rather than general good fortune.