Lagerstätte is a well-bedded sequence of limestone layers containing an extremely well-preserved assemblage of fossils. Paleontologists distinguish two kinds: Konzentrat-Lagerstätten (concentration Lagerstätten) are deposits with a particular concentration of disarticulated organic hard parts, such as a bone bed. These Lagerstätten are less spectacular than the more famous Konservat-Lagerstätten. Their contents invariably display a large degree of time averaging, as the accumulation of bones in the absence of other sediment takes some time. Deposits with a high concentration of fossils that represent an in-situ community, such as reefs or oyster beds, are not considered Lagerstätten.