A
Lagerstätte (also spelled Lagerstatte and Lagerstaette) is
a fossil site exhibiting extraordinary preservation and often
faunal or floral diversity. The word translates from the German
as Lager and Stätte; literally meaning "place of storage";
the plural form is Lagerstätten).
Science
distinguishes two types of Lagerstätten:
Konzentrat-Lagerstätten (concentration
Lagerstätten)
Konzentrat-Lagerstätten are
deposits having a concentration of disarticulated organic hard
parts, such
as a bone bed. These Lagerstätten are generally less
important to science 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 ecological community, such as reefs
or oyster beds, are not considered Lagerstätten.
Konservat-Lagerstätten
(conservation Lagerstätten)
Konservat-Lagerstätten,
on the other hand, are
deposits known for the extraordinary preservation of fossilized
life forms, especially
where the soft parts are preserved. Such exquisite preservation
require specific 
environmental
conditions, such as anoxic (little or no oxygen) mud and
sediment
that inhibits bacterial decomposition processes for enough
time for mineral exchange, precipitation, and other chemical
processes
to form casts and films of delicate softer body parts.
Most
of the famous Lagerstätten
are Konservat-Lagerstätten. Perhaps the early Cambrian Burgess
Shale of Canada ranks among the most famous. The Chengjiang
Maotianshan Shales are even younger. These Lagerstätten
together with others have yielded enormous insights into the Cambrian
Explosion when most phyla in the tree
of life first appear in the fossil
record. There are
a large number of Lagerstätten
spread across the planet and geological time.
