A Fossil-Lagerstätte ( from Lager 'storage, lair' and Stätte 'place'; ) is a sedimentary deposit that preserves an exceptionally high amount of palaeontological information. Konzentrat-Lagerstätten preserve a high concentration of fossils, while Konservat-Lagerstätten offer exceptional fossil preservation, sometimes including preserved soft tissues. Konservat-Lagerstätten may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus delaying the decomposition of both gross and fine biological features until long after a durable impression was created in the surrounding matrix. Fossil-Lagerstätten span geological time from the Neoproterozoic era to the present.
Worldwide, some of the best examples of near-perfect fossilization are the Cambrian Maotianshan shales and Burgess Shale, the Ordovician Fezouata Biota, Beecher's Trilobite Bed, and Soom Shale, the Silurian Waukesha Biota, the Devonian Rhynie Chert, Hunsrück Slates, and Gogo Formation, the Carboniferous Mazon Creek, the Triassic Madygen Formation, the Jurassic Posidonia Shale and Solnhofen Limestone, the Cretaceous Yixian, Santana, and Agua Nueva formations and the Tanis Fossil Site, the Eocene Fur Formation, Green River Formation, Messel Formation and Monte Bolca, the Miocene Foulden Maar and Ashfall Fossil Beds, the Pliocene Gray Fossil Site, and the Pleistocene Naracoorte Caves and La Brea Tar Pits.
Types Palaeontologists distinguish two major kinds:The term was originally coined by Adolf Seilacher in: The term was redefined by Julien Kimmig and James D. Schiffbauer in: Konzentrat-Lagerstätten (concentration Lagerstätten) are deposits with a particular "concentration" of disarticulated organic hard parts, such as a bone bed. 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. Konservat-Lagerstätten (conservation Lagerstätten) are deposits known for the exceptional preservation of fossilized organisms or traces. The individual taphonomy of the fossils varies with the sites. Conservation Lagerstätten are crucial in elucidating important moments in the history and evolution of life. For example, the Burgess Shale of British Columbia is associated with the Cambrian explosion, and the Solnhofen limestone with the earliest known bird, Archaeopteryx.
Preservation Konservat-Lagerstätten preserve lightly sclerotized and soft-bodied organisms or traces of organisms that are not otherwise preserved in the usual shelly and bony fossil record; thus, they offer more complete records of ancient biodiversity and behavior and enable some reconstruction of the palaeoecology of ancient aquatic communities. In 1986, Simon Conway Morris calculated only about 14% of genera in the Burgess Shale had possessed biomineralized tissues in life. The affinities of the shelly elements of conodonts were mysterious until the associated soft tissues were discovered near Edinburgh, Scotland, in the Granton Lower Oil Shale of the Carboniferous. Information from the broader range of organisms found in Lagerstätten have contributed to recent phylogenetic reconstructions of some major metazoan groups. Lagerstätten seem to be temporally autocorrelated, perhaps because global environmental factors such as climate might affect their deposition.
A number of taphonomic pathways may produce Konservat-Lagerstätten: Phosphatization (replacing soft tissues with phosphate, such as Orsten-type and Doushantuo-type preservations). Silicification (replacing or entombing soft tissues with silica, such as petrified wood or Bitter Springs-type preservation). Kerogenization (soft tissues converted into inert carbonaceous films, as found in Burgess Shale-type preservation). Aluminosilification (replacing or coating soft tissues with films of aluminosilicate minerals). Pyritization (replacing soft tissues with pyrite, such as the exquisite detail found in Beecher's trilobite-type preservation). Calcification (replacing or soft tissues with calcite minerals). Siderite or calcite nodules (chemicals released by decaying soft tissue modify the surrounding sediment into a siderite concretion or coal ball encasing the fossil, as found in the Mazon Creek fossil beds). Rapid sediment cementation (impressions of soft tissue preserved through casts and molds in the surrounding sediment, such as Ediacaran-type preservation facilitated by microbial mats). Amber (soft tissues encased in hardened tree resin). The identification of a fossil site as a Konservat-Lagerstätte may be based on a number of different factors which constitute "exceptional preservation". These may include the completeness of specimens, soft tissue preservation, fine-scale detail, taxonomic richness, distinctive taphonomic pathways (often multiple at the same site), the extent of the fossil layer in time and space, and particular sediment facies encouraging preservation.
Examples
Site(s)AgeLocation Significance Notable fossils/organismsDoushantuo Formation600–555 Ma Guizhou Province, Spans the poorly understood interval between the end of the Cryogenian period and the late Ediacaran Avalon explosion. Mistaken Point
(including the Drook, Briscal, Mistaken Point, Trepassey, and Fermeuse Formations.)565 MaNewfoundland, This site contains one of the most diverse and well-preserved collections of Precambrian fossils.Ediacara Hills555 Ma South The type location the Ediacaran period, and has preserved a significant amount of fossils from that time.Maotianshan Shales (Chengjiang) 518 Ma Yunnan, The preservation of an extremely diverse faunal assemblage renders the Maotianshan Shales the world's most important formation for understanding the evolution of early multi-cellular life. Microscopic animals like Yicaris are preserved here, showing the presence of an Orsten-type deposit within the formation. This site also includes the Xiazhuang biota.Sirius Passet523-518 MaGreenland, A site known for its fauna, and that they were most likely preserved by a death mask. It is a part of the larger Buen Formation, and has a fauna similar to the Maotianshan shales.Burgess Shale508 MaBritish Columbia, One of the most famous fossil localities in the world. It is famous for the exceptional preservation of the soft parts of its fossils. At 508 million years old (middle Cambrian), it is one of the earliest fossil beds containing soft-part imprints.Kinnekulle Orsten and Alum Shale500 MaThe Orsten sites reveals the oldest well-documented benthic meiofauna in the fossil record. Fossils such as microfossils of arthropods like free-living pentastomids are known. Multiple "Orsten-type" lagerstätten are also known from other countries.Fezouata Formationabout 485 MaDraa Valley, It was deposited in a marine environment, and is known for its exceptionally preserved fossils, filling an important preservational window beyond the earlier and more common Cambrian Burgess shale-type deposits.Winneshiek Shale460 MaDecorah, Iowa, A Middle Ordovician site confined to a large impact Crater that is known for exceptionally exquisite preservation of conodonts, bivalved arthropods, and the earliest eurypterids in the fossil record.Beecher's Trilobite Bed460? Ma New York, Noted exceptionally preserved trilobites with soft tissue preserved by pyrite replacement. Pyritisation allows the use of X-rays to study fine detail of preserved soft body parts.Soom Shale450? MaKnown for its remarkable preservation of soft-tissue in fossil material. Deposited in still waters, the unit lacks bioturbation, perhaps indicating anoxic conditions.Waukesha Biota (Brandon Bridge Formation)~435 MaEarly SilurianWisconsin, Well-studied site known for the exceptional preservation of its diverse, soft-bodied and lightly skeletonized fauna, includes many major taxa found nowhere else in strata of similar age. It was one of the first fossil sites with soft bodied preservation known to science. Herefordshire Lagerstätte (Coalbrookdale Formation)~430 MaHerefordshire, Known for the well-preserved fossils of various invertebrate animals many of which are in their three-dimensional structures. Fossils are preserved within volcanic ash, because of that sometimes this site has been compared to Pompeii. Some of the fossils are regarded as earliest evidences and evolutionary origin of some of the major groups of modern animals.Bertie Group422.9-416 MaOntario & New York State, and This limestone have produced thousands of fossil eurypterids, such as giant Acutiramus and well-known Eurypterus, as well as other fauna like scorpions and fish.Rhynie chert400 MaScotland, The Rhynie chert contains exceptionally preserved plant, fungus, lichen and animal material (euthycarcinoids, branchiopods, arachnids, hexapods, etc.) preserved in place by an overlying volcanic deposit and hot springs. As well as one of the first known fully terrestrial ecosystems.Hunsrück Slates (Bundenbach)Rheinland-Pfalz, The Hunsrück slates are one of the few marine Devonian lagerstätte having soft tissue preservation, and in many cases fossils are coated by a pyritic surface layer.Gogo Formation380 Ma (Frasnian)Western The fossils of the Gogo Formation display three-dimensional soft-tissue preservation of tissues as fragile as nerves and embryos with umbilical cords. Over fifty species of fish have been described from the formation, and arthropods.Miguasha National Park (Escuminac Formation)370 MaQuébec, Some of the fish, fauna, and spore fossils found at Miguasha are rare and ancient species. For example, Eusthenopteron is sarcopterygian that shares characters with early tetrapods.Waterloo Farm Lagerstätte (Witpoort Formation)360 MaImportant site that providing the only record of a high latitude (near polar) coastal ecosystem, overturning numerous assumptions about high latitude conditions during the latest Devonian.East Kirkton Quarry335 MaWest Lothian, Scotland, This site has produced numerous well-preserved fossils of early tetrapods like temnospondyls or reptiliomorphs, and large arthropods like scorpions or eurypterids.Bear Gulch Limestone324 MaMontana, A limestone-rich geological lens in central Montana. It is renowned for its unusual and ecologically diverse fossil composition of chondrichthyans, the group of cartilaginous fish containing modern sharks, rays, and chimaeras. Other animals like brachiopods, ray finned fish, arthropods, and the possible mollusk Typhloesus are also known from the site.Joggins Fossil Cliffs (Joggins Formation)315 MaNova Scotia, A fossil site that preserves a diverse terrestrial ecosystem consisting of plants like lycopsids, giant arthropods, fish, and the oldest known sauropsid, Hylonomus.Mazon Creek310 MaIllinois, A conservation lagerstätte found near Morris, in Grundy County, Illinois. The fossils from this site are preserved in ironstone concretions with exceptional detail. The fossils were preserved in a large delta system that covered much of the area. The state fossil of Illinois, the enigmatic animal Tullimonstrum, is only known from these deposits.Montceau-les-Mines300 MaExceptional preservation of Late Carboniferous fossil biota are known, including various vertebrates and arthropods, as well as plants.Chemnitz petrified forest291 MaSaxony, A petrified forest in Germany that is composed of Arthropitys bistriata, a type of Calamites, giant horsetails that are ancestors of modern horsetails, found on this location with never seen multiple branches. Many more plants and animals from this excavation are still in an ongoing research.Kupferschiefer259–255 Ma(North-Central Europe)