Many of the entries in this list are considered Lagerstätten (sedimentary deposits that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues).
Fossils may be found either associated with a geological formation or at a single geographic site.
Geological formations consist of rock that was deposited during a specific period of time.
In contrast, extensive formations associated with large areas may be equivalently represented at many locations.
For example, sites associated with hominin, particularly caves, are frequently not identified with a named geologic formation.