Well-preserved basal arthropod Opabinia from Burgess Shale Lagerstätte

A Lagerstätte (German: [ˈlaːɡɐˌʃtɛtə], from Lager 'storage, lair' Stätte 'place'; plural Lagerstätten) is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These formations 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. 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 Soom Shale, the Silurian Waukesha Biota, the Devonian 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, the Eocene Green River Formation, the Miocene Foulden Maar and Ashfall Fossil Beds, the Pliocene Gray Fossil Site, the Pleistocene Naracoorte Caves, the La Brea Tar Pits, and the Tanis Fossil Site.


Palaeontologists distinguish two kinds:

  1. 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.
  2. 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.
Archaeopteryx specimen from Solnhofen Lagerstätte


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 Lagerstätten. The following is an incomplete list:

Important Lagerstätten

The world's major Lagerstätten include:


Site(s) Age Location Significance Notable fossils/organisms
Nonesuch Formation 1083-1070 Ma Michigan, USA A Mesoproterozoic lake containing exceptionally preserved limnic microbes.

Lakhanda Lagerstätte

1030-1000 Ma

Uchur-Maya Depression, Russia

A site preserving evidence of trophic interactions from the Boring Billion.

Bitter Springs

1000–850 Ma

South Australia

Preserved fossils include cyanobacteria microfossils.

An early Stromatolite
Dolores Creek Formation 950 Ma Yukon, Canada An Early Tonian site containing pyritised macroalgal fossils.

Chichkan Lagerstätte

775 Ma


A site from the transition between the prokaryote-dominated biota of the Early Neoproterozoic and the eukaryote-dominated biota of the Late Neoproterozoic and Phanerozoic.

Doushantuo Formation

600–555 Ma

Guizhou Province, China

Spans the poorly understood interval between the end of the Cryogenian period and the Late Ediacaran Avalon explosion.

An ediacaran embryo-like fossil
Portfjeld Formation 570 Ma North Greenland A Middle Ediacaran biota from the continent of Laurentia exhibiting Doushantuo-type preservation.

Mistaken Point

565 Ma

Newfoundland, Canada

This site contains one of the most diverse and well-preserved collections of Precambrian fossils.

Frondose ediacaran organisms

Ediacara Hills

555 Ma

South Australia

The type location the Ediacaran period, and has preserved a significant amount of fossils from that time.

Spriggina floundersi, a worm-like organism
Shibantan Lagerstätte 551-543 Ma Hubei, China A terminal Ediacaran fossil assemblage preserving life forms living just before the Proterozoic-Phanerozoic transition.
Gaojiashan Lagerstätte 551-541 Ma Shaanxi, China A lagerstätte documenting tube growth patterns of Cloudina.

Khatyspyt Lagerstätte

544 Ma

Yakutia, Russia

A Late Ediacaran lagerstätte preserving an Avalon-type biota.


Site(s) Age Location Significance Notable fossils/organisms

Maotianshan Shales (Chengjiang)

518 Ma

Yunnan, China

The preservation of an extremely diverse faunal assemblage renders the Maotianshan shale the world's most important for understanding the evolution of early multi-cellular life.

Haikouichthys, a primitive craniate

Qingjiang biota

518 Ma

Hubei, China

This site is particularly notable due to both the large proportion of new taxa represented (approximately 53% of the specimens), and the notable volume of soft-body tissue preservation.

Duplapex, a hymenocarine arthropod

Sirius Passet

518 Ma


A site known for its fauna, and that they were most likely preserved by a death mask.

Kerygmachela, a dinocaridid-like lobopodian

Sinsk Algal Lens

518 Ma

Yakutia, Russia

One of the oldest known Cambrian Lagerstätten.

A reconstruction of the large Lobopodian Siberion

Emu Bay Shale

513 Ma

South Australia

Noted soft tissue mineralization, most often of blocky apatite or fibrous calcium carbonate, including the oldest phosphatized muscle tissue.

Oestokerkus, a megacheiran arthropod

Kaili Formation

513–501 Ma

Guizhou, China

The middle part of the Kaili Formation, the Oryctocephalus indicus Zone, contains a Burgess Shale-type Lagerstätte with many well-preserved fossils known collectively as the Kaili Biota.

Pararotadiscus a cambroernid animal

Murero Lagerstätte

511-503 Ma


Thanks to the paleontological content, mainly trilobites, fourteen biozones have been established, the most precise biozonation for this time interval in the world. It also records in detail the so-called Valdemiedes event, the mass extinction episode at the end of the Lower Cambrian.

Eccaparadoxides trilobites showing sexual dimorphism

Blackberry Hill

~510–500 Ma

Central Wisconsin, US

This site preserves some of the oldest evidence of multicellular life walking out of the ocean, and onto dry land (in the form of large mollusks and euthycarcinoid arthropods).

Mosineia, a euthycarcinoid arthropod

Burgess Shale

508 Ma

British Columbia, Canada

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.

Anomalocaris, a predatory radiodont

Spence Shale

507 Ma

Northeastern Utah, Southeastern Idaho, US

A site known for its abundant Cambrian trilobites and the preservation of Burgess Shale-type fossils.

Hyoliths, most likely lophophorates

Linyi Lagerstätte

504 Ma

Shandong, China

A lagerstätte recognised for its exceptional preservation of arthropod limbs, intestines, and eyes.

Reconstruction of the arthropod species Thelxiope spinosa, known from the site

Wheeler Shale (House Range)

504 Ma

Western Utah, US

A world-famous locality known for its prolific agnostid and Elrathia kingii trilobite remains. Varied soft bodied organisms are also locally preserved, including Naraoia, Wiwaxia and Hallucigenia.

Elrathia sp. trilobites

Marjum Formation

502 Ma

Western Utah, US

A site known for its occasional preservation of soft-bodied tissue, and diverse assemblage.

Branchiocaris a pelagic hymenocarine

Weeks Formation

500 Ma

Western Utah, US

A site that is dominated by trilobites and brachiopods, but also comprising various soft-bodied organisms, such as Falcatamacaris.

Beckwithia, an aglaspidid trilobite relative

Kinnekulle Orsten and Alum Shale

500 Ma


The 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.

Cambropachycope, a stem-group mandibulate arthropod


Site(s) Age Location Significance Notable fossils/organisms

Fezouata Formation

about 485 Ma

Draa Valley, Morocco

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.

Aegirocassis, a giant hurdiid radiodont

Liexi fauna

About 470 Ma (early-middle Floian)

Hunan Province, China

Preserves Early Ordovician fauna with soft tissue, includes not only Cambrian relics but also taxa originated during Ordovician.

Castle Bank

About 461 Ma

Llandrindod Wells, Wales

A unique environment deposited during the middle Ordovician that possibly shows iconic groups from Cambrian lagerstättes, like Opabiniids and Megacheirans, survived for longer than what was thought.

Diagram of Mieridduryn, an opabiniid-like panarthropod

Douglas Dam Member

460 Ma

Tennessee, US

Low-diversity assemblage of arthropod fossils, which are preserved well because of volcanic ash.
Chasmataspis, a horseshoe crab-like chasmataspid arthropod

Winneshiek Shale

460 Ma

Decorah, Iowa

A Middle Ordovician site known for exceptionally exquisite preservation of conodonts, and the earliest eurypterids in the fossil record.

Pentecopterus, the oldest known eurypterid

Beecher's Trilobite Bed

460? Ma

New York, US

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.

A pair of Triarthrus trilobites with pyritized soft-tissue

Harding Sandstone

? (Sandbian)

Colorado, US

Although preservation is not excellent, this lagoonal site provides early vertebrate fossils such as Astraspis and Eriptychius.
Eriptychius, an early agnathan

Walcott-Rust Quarry

about 455? Ma

New York, US

This site is an excellent example of an obrution (rapid burial or "smothered") Lagerstätte.
Unique preservation of trilobite appendages resulted from early cementation of the surrounding rock and spar filling of the interior cavity of the appendages.

Isotelus gigas, a large asaphid trilobite
Big hill Lagerstätte about 450? Mya Michigan, US A site known for its preservation of soft-bodied medusae (jellyfish), as well as linguloid brachiopods, algae, and arthropods (namely chasmataspidids, leperditid ostracods, and eurypterids).
Hoplitaspis, chasmataspid arthropod

Brechin Lagerstätte

450 Ma

Ontario, Canada

Known for preserving one of the most diverse crinoid fauna of the Katian.

Tomlinsonus, a marrellomorph

Soom Shale

450? Ma

South Africa

Known for its remarkable preservation of soft-tissue in fossil material. Deposited in still waters, the unit lacks bioturbation, perhaps indicating anoxic conditions.

Promissum, a conodont known from rare soft-tissues

Tafilalt Biota

? (Sandbian-middle Katian)

Tafilalt, Morocco

Known from range of non-biomineralised and soft-bodied organisms in polar environment.

"Eldonia" barvera, an eldoniid

Cat Head Member

? (middle Katian)

Manitoba, Canada

Fossils like algae, conulariids and trilobites are known from this site.

Georgian Bay Formation

449-445.6 Ma

Manitoulin, Canada

Low-diversity assemblage of arthropod fossils.
Orcanopterus, a middle-sized waeringopterid eurypterid

William Lake (Stony Mountain Formation)

445 Ma

Manitoba, Canada

Well-preserved fossils like jellyfish, xiphosurans, sea spiders are known from this site, it is important since many of the fossils are unknown in other Ordovician sites.
Lunataspis aurora, an early xiphosuran known in two sites

Airport Cove

445 Ma

Manitoba, Canada

Fossils like eurypterids, algae and xiphosurans are preserved in this site.


Site(s) Age Location Significance Notable fossils/organisms

Kalana Lagerstätte

~440 Ma


Known for well preserved fossils of algae and crinoids.

Kalanaspis, the earliest known osteostracan

Chongqing Lagerstätte (Huixingshao Formation)

436 Ma

Chongqing, China

This site preserved complete fossils of earliest jawed vertebrates, as well as some galeaspids and eurypterids.
Xiushanosteus, the earliest placoderm

Waukesha Biota (Brandon Bridge Formation)

~435 Ma
Early Silurian

Wisconsin, US

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.

Parioscorpio, an enigmatic arthropod

Herefordshire Lagerstätte (Coalbrookdale Formation)

~430 Ma

Herefordshire, UK

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.

Offacolus, a euchelicerate

Earamosa lagerstätte

~425 Ma

Ontario & New York (state)

Known for preservation of both hard and soft bodied organisms in great detail.

Eramoscorpius, an early scorpion

Bertie Group

422.9-416 Ma

Ontario & New York State

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.

Nerepisacanthus, an acanthodian

Tonoloway Formation

~420 Ma

Pennsylvania, US

Known from exceptionally preserved mass assemblage of Eurypterus, the most abundant eurypterid in the fossil record.
Recobstruction of Eurypterus

Rochester Shale

415 Ma

New York, US and Ontario, Canada

Echinoderms (such as crinoids) and trilobites are known from Lewiston Member in this shale.
Arctinurus, one of the trilobites from this site


Site(s) Age Location Significance Notable fossils/organisms
Rhynie chert 400 Ma Scotland, UK The Rhynie chert contains exceptionally preserved plant, fungus, lichen and animal material preserved in place by an overlying volcanic deposit. As well as one of the first known fully terrestrial ecosystems.
Asteroxylon, an early vascular plant related to lycopods
Waxweiler Lagerstätte (Klerf Formation) 409-392 Ma Eifel, Germany Waxweiler Lagerstätte is known from well-preserved fossils of chelicerates, giant claw of Jaekelopterus rhenaniae shows the largest arthropod ever known.
Jaekelopterus, around 2.5 m-long eurypterid
Heckelmann Mill 395 Ma Rhineland-Palatinate, Germany Heckelmann Mill preserves well preserved rhinocaridid archaeostracan phyllocarids, along with exceptionally abundant crinoid holdfasts from the late Emsian.
Hunsrück Slates (Bundenbach) 390 Ma Rheinland-Pfalz, Germany 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.
Schinderhannes bartelsi, the youngest known radiodont
Gogo Formation 380 Ma (Frasnian) Western Australia 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.
Materpiscis, a ptyctodontid placoderm fish that is the oldest vertebrate known to give live birth
Miguasha National Park (Escuminac Formation) 370 Ma Québec, Canada 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.
Fossil of lungfish Scaumenacia and antiarch placoderm Bothriolepis
Kowala Lagerstätte ~368 Ma Świętokrzyskie Voivodeship, Poland A Late Devonian site known for its fossils of non-biomineralised algae and arthropods.
Maïder Basin 368 Ma (for Thylacocephalan Layer) Anti-Atlas, Morocco Thylacocephalan Layer and Hangenberg Black Shale in this basin provides well-preserved fossils of Famennian fauna, including chondrichthyans and placoderms that preserved soft tissues.
Amazichthys, pelagic placoderm with preserved soft tissue
Strud ? (Late Famennian) Namur Province, Belgium Mainly juvenile placoderms are known, suggesting this site would be nursery site of placoderms. Various biota like tetrapods, arthropods and plants are also known, Strudiella from this site may be the earliest insect, but its affinity is disputed.
Strudops, the earliest known notostracan.
Canowindra, New South Wales (Mandagery Sandstone) 360 Ma Australia An accidentally discovered Lagerstätte known for its exceptional preservation of Sarcopterygian and Placoderm fish.
Mandageria, a lobe-finned fish that is the NSW State Fossil Emblem in Australia
Waterloo Farm lagerstätte (Witpoort Formation) 360 Ma South Africa Important 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.
Priscomyzon, the oldest known genus of lamprey


Site(s) Age Location Significance Notable fossils/organisms
Granton Shrimp Bed ? (Dinantian) Firth of Forth, Scotland Dominated by well-preserved crustacean fossils, this site provided first body fossil of Clydagnathus which solved long-lasted mystery of conodont fossils.
East Kirkton Quarry 335 Ma West Lothian, Scotland This site has produced numerous well-preserved fossils of early tetrapods like temnospondyls or reptiliomorphs, and large arthropods like scorpions or eurypterids.
Silvanerpeton, a possible reptiliomorph
Bear Gulch Limestone 324 Ma Montana, US 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.
Falcatus, a holocephalian which males had large fin spine
Bickershaw ? (Langsettian) Lancashire, England This locality contains exceptionally preserved fossils within nodules. Arthropods have greater diversity, many of which are aquatic ones that lived in brackish environment.
Valloisella, a xiphosuran
Joggins Fossil Cliffs (Joggins Formation) 315 Ma Nova Scotia, Canada A fossil site that preserves a diverse terrestrial ecosystem consisting of plants like lycopsids, giant arthropods, fish, and the oldest known sauropsid, Hylonomus.
Hylonomus, the oldest known sauropsid in the fossil record
Linton Diamond Coal Mine 310 Ma Ohio, US A site known for its number of prehistoric tetrapods, like the lepospondyl Diceratosaurus.
The lepospondyl tetrapod Diceratosaurus
Mazon Creek 310 Ma Illinois, US A conservation lagerstätte found near Morris, in Grundy County, Illinois. The fossils from this site are preserved in ironstone concretions with exceptional detail. The state fossil of Illinois, the enigmatic animal Tullimonstrum, is only known from these deposits.
Tullimonstrum, an enigmatic animal
Kinney Brick Quarry (Atrasado Formation) around 307 Ma New Mexico, US This site is known from rich fish fossils with preserved soft tissues, that lived in lagoonal environment. Dozens of fish genera are known, ranging from chondrichthyeans like ctenacanths and hybodonts, to actinopterygians and sarcopterygians.
Dracopristis, a ctenacanth
Montceau-les-Mines 300 Ma France Exceptional preservation of Late Carboniferous fossil biota are known, including various vertebrates and arthropods, as well as plants.
Idmonarachne, an arachnid that is related to spiders
Hamilton Quarry 300 Ma Kansas, US This site is known for its diverse assemblage of unusually well-preserved marine, euryhaline, freshwater, flying, and terrestrial fossils (invertebrates, vertebrates, and plants). This extraordinary mix of fossils suggests it was once an estuary.
Spinoaequalis, a semi-aquatic diapsid


Site(s) Age Location Significance Notable fossils/organisms
Franchesse 292 Ma Massif Central, France A Sakmarian seymouriamorph lagerstätte from the Bourbon l'Archambault Basin in the French Massif Central containing hundreds of complete seymouriamorph specimens.
Chemnitz petrified forest 291 Ma Saxony, Germany 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.
Large trunks of Arthropitys at Chemnitz
Mangrullo Formation about 285–275 Ma (Artinskian) Uruguay This site is known for its abundant mesosaur fossils. It also contains the oldest known Konservat-Lagerstätte in South America, as well as the oldest known fossils of amniote embryos.
Stereosternum, an aquatic mesosaurid reptile
Toploje Member 273-264 Ma Prince Charles Mountains, Antarctica This site preserves a high-latitude fauna in exceptional position before the large extinctions that happened later in the Permian.
Onder Karoo 266.9–264.28 Ma Karoo Basin, South Africa A high latitude, cool-temperate lacustrine ecosystem preserving detailed plant and insect fossils.
Sakamena Group 260–247 Ma Madagascar Lower Sakamena Formation (Permian) and Middle Sakamena Formation (Triassic) contain fossils of animals lived around wetland environment, such as semi-aquatic and gliding neodiapsids.
Claudiosaurus, aquatic neodiapsid reptile
Kupferschiefer 259–255 Ma Central Europe This site deposited in an open marine and shallow marine environment provides fossils of reptiles as well as many fish.
Weigeltisaurus, gliding weigeltisaurid reptile
Huopu Lagerstätte ~255 Ma Guizhou, China A plant fossil site documenting floral dynamics between the end-Guadalupian and end-Permian extinction events.


Site(s) Age Location Significance Notable fossils/organisms
Guiyang biota 250.8 Ma Guizhou Province, China The oldest known Mesozoic lagerstätte (Dienerian). It preserves taxa belonging to 12 classes and 19 orders, including several species of fish.
Teffichthys elegans, a perleidiform ray-finned fish
Paris biota ~249 Ma Idaho, Nevada, USA This earliest Spathian aged assemblage preserves fossils belonging to 7 phyla and 20 orders, combining Paleozoic groups (e.g. leptomitid protomonaxonid sponges otherwise known from the early Paleozoic) with members of the Modern evolutionary fauna (e.g. gladius-bearing coleoids).
Ankitokazocaris triassica is a thylacocephalan from the Paris biota
Jialingjiang Formation 249.2–247.2 Ma Hubei Province, China This site preserved aquatic reptiles soon after Permian extinction. Hupehsuchians are exclusively known from here, and already got unique ecology like filter feeding.
Eretmorhipis, a hupehsuchian that potentially had platypus-like ecology
Nanlinghu Formation 248 Ma Anhui Province, China This site provides important fossils to show early evolution of ichthyosauriforms.
Cartorhynchus, a primitive ichthyosauriform
Petropavlovka Formation 248 Ma Orenburg Oblast, Russia A site known for preserving oligochaetes, whose fossil record is extremely sparse.
Luoping Biota (Guanling Formation) ~247-245 Ma Yunnan, China Various marine animals are preserved in this site, showing how marine ecosystem recovered after Permian extinction.
Atopodentatus, a herbivorous marine reptile that possessed a hammer-shaped head.
Grès à Voltzia 245 Ma France A fossil site remarkable for its detailed myriapod specimens.
Besano Formation 242 Ma Alps, Italy and Switzerland This formation is designated as a World Heritage Site, as it is famous for its preservation of Middle Triassic marine life including fish and aquatic reptiles.
Tanystropheus, a long-necked archosauromorph
Xingyi biota (Zhuganpo Formation) ? (Upper Ladinian - Lower Carnian) Guizhou and Yunnan, China Previously considered as part of Falang Formation, this site yields many articulated skeletons of marine reptiles, as well as fish and invertebrates.
Keichousaurus, common sauropterygian from this site
Guanling biota (Xiaowa Formation) ? (Carnian) Guizhou, China Like Xingi Biota, this site also yields well-preserved marine fauna, especially many species of thalattosaurs are known.
Odontochelys, an early pantestudine (relative of turtles)
Polzberg 233 Ma Austria A site known for exceptional preservation of bromalites and of cartilage, deposited during the Carnian Pluvial Event.
Madygen Formation 230 Ma Kyrgyzstan The Madygen Formation is renowned for the preservation of more than 20,000 fossil insects, making it one of the richest Triassic Lagerstätten in the world. Other vertebrate fossils as fish, amphibians, reptiles and synapsids have been recovered from the formation too, as well as minor fossil flora.
Longisquama, a bizarre reptile with long growths protruding from its back
Cow Branch Formation 230 Ma Virginia, US This site preserves a wide variety of organisms (including Fish, reptiles, arachnids, and insects).
Mecistotrachelos, a gliding reptile distantly related to archosauromorphs, like crocodylians and dinosaurs


Site(s) Age Location Significance Notable fossils/organisms
Osteno (Moltrasio Formation) 196-188 Ma Italy Several kinds of marine biota such as fish, crustaceans, cephalopods polychaetes, and nematodes have been recovered. This site is the only fossil deposit in Italy in which soft bodies are preserved other than Monte Bolca.
Squaloraja, ray-like chimaeriform
Ya Ha Tinda 183 Ma Alberta, Canada A fossil site notable for containing abundant and extremely well-preserved vampire squid, being the largest concentration of vampire squid fossils outside the Tethys Ocean, and for being deposited during the Toarcian Oceanic Anoxic Event (TOAE).
Strawberry Bank 183 Ma Somerset, England A site from the TOAE documenting marine life during the recovery from the Triassic-Jurassic extinction event as well as the turmoil of the TOAE. The oldest pseudoplanktonic barnacles in the fossil record, near-complete ichthyosaur skeletons, and evidence of ichthyosaur niche partitioning are preserved at this site.
Holzmaden/Posidonia Shale 183 Ma Württemberg, Germany The Sachrang member is among the most important formations of the Toarcian boundary, due to the concentrations of exceptionally well-preserved complete skeletons of fossil marine fish and reptiles. It was also deposited during the TOAE.
A specimen of the ichthyosaur Stenopterygius crassicostatus with preserved young
Mesa Chelonia 164.6 Ma Shanshan County, China This site is notable because it contains a large turtle bonebed, containing specimens of the genus Annemys. This bonebed contains up to an estimated 36 turtles per square meter.
La Voulte-sur-Rhône 160 Mya Ardèche, France La Voulte-sur-Rhône, in the Ardèche region of southwestern France, offers paleontologists an outstanding view of an undisturbed paleoecosystem that was preserved in fine detail. Notable finds include retinal structures in the eyes of thylacocephalan arthropods, and fossilized relatives of the modern day vampire squid, like Vampyronassa rhodanica.
A rare well-preserved cephalopod, Rhomboteuthis
Karabastau Formation 155.7 Ma Kazakhstan This site is an important locality for insect fossils that has been studied since the early 20th century, alongside the rarer remains of vertebrates, including pterosaurs, salamanders, lizards and crocodiles.
Sordes, small pterosaur with visible soft-tissues preserved
Tiaojishan Formation 165-153 Ma Liaoning Province, China It is known for its exceptionally preserved fossils, including those

of plants, insects and vertebrates. It is made up mainly of pyroclastic rock interspersed with basic volcanic and sedimentary rocks.

Anchiornis, small feathered anchiornithid dinosaur
Talbragar fossil site 151 Ma New South Wales, Australia This bed is part of Purlawaugh Formation, and provided fauna like fish and insects that lived around the lake.
Cavenderichthys, a teleost known from this site
Cleveland-Lloyd Dinosaur Quarry 150 Ma Utah, US Jurassic National Monument, at the site of the Cleveland-Lloyd Dinosaur Quarry, well known for containing the densest concentration of Jurassic dinosaur fossils ever found, is a paleontological site located near Cleveland, Utah, in the San Rafael Swell, a part of the geological layers known as the Morrison Formation. Up to 15,000 have been excavated from this site alone.
Allosaurus, the largest predator of the quarry
Solnhofen Limestone 145 Ma Bavaria, Germany This site is unique as it preserves a rare assemblage of fossilized organisms, including highly detailed imprints of soft bodied organisms such as sea jellies. The most familiar fossils of the Solnhofen Plattenkalk include the early feathered theropod dinosaur Archaeopteryx preserved in such detail that they are among the most famous and most beautiful fossils in the world.
The Berlin Specimen of Archaeopteryx lithographica
Canjuers Lagerstätte 145 Ma France This site shows a high amount of biodiversity, including reptiles, invertebrates, fish, and other organisms.
Pleurosaurus, an aquatic rhynchocephalian
Agardhfjellet Formation 150-140 Ma Spitsbergen, Norway The formation contains the Slottsmøya Member, a highly fossiliferous unit where many ichthyosaur and plesiosaur fossils have been found, as well as abundant and well preserved fossils of invertebrates.
Pliosaurus, a large thalassophonean pliosaurid which was informally known as "Predator X"


Site(s) Age Location Significance Notable fossils/organisms
Angeac-Charente ~141 Ma Charente, France A lagerstätte preserving both vertebrate and invertebrate fossils from the poorly represented Berriasian stage known for its taphonomic and sedimentological ‘frozen scenes’.
El Montsec (La Pedrera de Rúbies Formation) ~140-125 Ma Catalonia, Spain Known from exceptional preservation of fossils like insect and other arthropod fossils, as well as some vertebrates.
Montsecosuchus, atoposaurid crocodylomorph
Las Hoyas about 125 Ma (Barremian) Cuenca, Spain The site is mostly known for its exquisitely preserved dinosaurs, especially enantiornithines. The lithology of the formation mostly consists of lacustarine limestone deposited in a freshwater wetland environment.
Concornis, an early enantiornithean
Yixian Formation about 125–121 Ma Liaoning, China The Yixian Formation is well known for its great diversity of well-preserved specimens and its feathered dinosaurs, such as the large tyrannosauroid Yutyrannus, the therizinosaur Beipiaosaurus, and various small birds, along with a selection of other dinosaurs, such as the iguanodontian Bolong, the sauropod Dongbeititan and the ceratopsian Psittacosaurus. Other biota included the troodontid Mei, the dromaeosaurid Tianyuraptor, and the compsognathid Sinosauropteryx.
Sinosauropteryx, the first non-avain dinosaur with evidence of feathers to have been recognized
Jiufotang Formation about 122-119 Ma (Aptian) Liaoning, China This formation overlies the slightly older Yixian Formation and preserved very similar species, including a wide variety of dinosaurs such as the ceratopsian Psittacosaurus and the early bird Confuciusornis, both of which are also found in the Yixian Formation. Also notable are the very abundant specimens of the dromaeosaurid Microraptor, which is known from up to 300 specimens and is among the most common animals found here.
Microraptor had four wings and is believed to have evolved powered flight independently of true birds.
Shengjinkou Formation about 120 Ma Xinjiang, China Part of the finds from this site consisted of dense concentrations of pterosaur bones, associated with soft tissues and eggs. The site represented a nesting colony that storm floods had covered with mud. Dozens of individuals could be secured from a total that in 2014 was estimated to run into the many hundreds.
Hamititan, a large titanosaurian sauropod
Xiagou Formation about 120–115? Ma Gansu, China This site is known outside the specialized world of Chinese geology as the site of a Lagerstätte in which the fossils were preserved of Gansus yumenensis, the earliest true modern bird.
Gansus is among the earliest known modern birds
Paja Formation 130-113 Ma Colombia This site is famous for its vertebrate fossils and is the richest Mesozoic fossiliferous formation of Colombia. Several marine reptile fossils of plesiosaurs, pliosaurs, ichthyosauras and turtles have been described from the formation and it hosts the only dinosaur fossils described in the country to date; Padillasaurus.
Desmatochelys, a protostegid and one of the oldest known turtle fossils
Koonwarra Fossil Bed around 118-115 Ma Victoria, Australia This site is composed of mudstone sediment thought to have been laid down in a freshwater lake. Arthropods, fish and plant fossils are known from this site.
Tarwinia, a large sized stem-flea
Crato Formation 113 Ma northeast Brazil The Crato Formation earns the designation of Lagerstätte due to an exceedingly well preserved and diverse fossil faunal assemblage. Some 25 species of fossil fishes are often found with stomach contents preserved, enabling paleontologists to study predator-prey relationships in this ecosystem. There are also fine examples of pterosaurs, reptiles and amphibians, invertebrates (particularly insects), and plants. Also known from this site is Ubirajara, the first non-avian dinosaur from the southern hemisphere with evidence of feathers.
Tupandactylus, a fossil pterosaur that was preserved with feathers and other soft tissues intact
Jinju Formation 112.4–106.5 Ma South Korea An ichnofossil assemblage notable for preserving the longest Cretaceous lepidosaur trackway.
Coptoclavidae beetle larva preserved at this locality
Tlayúa Formation 110 Ma Puebla, Mexico A marine lagerstätte preserving Albian actinopterygians.
Huehuecuetzpalli, possible bipedal lizard
Romualdo Formation 108–92 Ma Brazil The Romualdo Formation is a part of the Santana Group and has provided a rich assemblage of fossils; flora, fish, arthropods insects, turtles, snakes, dinosaurs, such as Irritator, and pterosaurs, including the genus Thalassodromeus. The stratigraphic units of the group contained several feathers of birds, among those the first record of Mesozoic birds in Brazil.
Tapejara, a common pterosaur in Brazil during the Early Cretaceous
Puy-Puy Lagerstätte 100.5 Ma France A paralic site preserving a variety of ichnofossils, along with some vertebrate remains. The site preserves evidence of plant-insect interaction.
Burmese Amber 99 Ma Myanmar More than 1,000 species of taxa have been described from ambers from Hukawng Valley. While it is important for understanding the evolution of biota, mainly insects, during the Cretaceous period, it is also extremely controversial by facing ethical issues due to its association with conflicts and labor conditions.
Oculudentavis, small-sized lizard
Haqel/Hjoula/al-Nammoura about 95 Ma Lebanon Notable among these is the Lebanese lagerstätten of the Late Cretaceous age, which contain a well-preserved variety of different fossils. Small animals like shrimp, octopus, stingrays, and bony fishes are common finds at these sites. Some of the rarest fossils from this locality include those of octopuses.
Ichthyoceros, pycnodont actinopterygian
Vallecillo (Agua Nueva Formation) 94–92 Ma Nuevo León, Mexico The site is noted for its qualities as a Konservat-Lagerstätte, with notable finds including the plesiosaur Mauriciosaurus and the possible shark Aquilolamna.
Mauriciosaurus, a short-necked plesiosaur
Akrabou Formation (Gara Sbaa and Agoult) ? (Turonian) Asfla, Morocco Marine site known for exceptionally preserved, three-dimensional fish fossils.
Smoky Hill Chalk 87–82 Ma Kansas and Nebraska, US A Cretaceous conservation Lagerstätte known primarily for its exceptionally well-preserved marine reptiles. Also known from this site are fossils of large bony fish such as Xiphactinus, mosasaurs, flying reptiles or pterosaurs (namely Pteranodon), flightless marine birds such as Hesperornis, and turtles.
Xiphactinus is famous for being found with another fish (Gillicus) preserved in its stomach.
Ingersoll Shale 85 Ma Alabama, US A Late Cretaceous (Santonian) informal geological unit in eastern Alabama. Fourteen theropod feathers assigned to birds and possibly dromaeosaurids have been recovered from the unit.
Auca Mahuevo 80 Ma Patagonia, Argentina A Cretaceous lagerstätte in the eroded badlands of the Patagonian province of Neuquén, Argentina. The sedimentary layers of the Anacleto Formation at Auca Mahuevo were deposited between 83.5 and 79.5 million years before the present and offers a view of a fossilized titanosaurid nesting site.
An egg from a titanosaurian sauropod
Zhucheng 66 Ma Shandong, China Zhucheng has been an important site for dinosaur excavation since 1960. The world's largest hadrosaurid fossil was found in Zhucheng in the 1980s. Other dinosaurs known from the area include the ceratopsian Zhuchengceratops (2010), the sauropod Zhuchengtitan (2017) and the theropod Zhuchengtyrannus (2011) which have all been described from deposits near and named after Zhucheng.
Zhuchengtyrannus, an Asian relative of the larger Tyrannosaurus
Tanis 66 Ma North Dakota, US Tanis is part of the heavily studied Hell Creek Formation, a group of rocks spanning four states in North America renowned for many significant fossil discoveries from the Upper Cretaceous and lower Paleocene. Tanis is a significant site because it appears to record the events from the first minutes until a few hours after the impact of the giant Chicxulub asteroid in extreme detail. This impact, which struck the Gulf of Mexico 66.043 million years ago, wiped out all non-avian dinosaurs and many other species (the so-called "K-Pg" or "K-T" extinction).
Some of the fossil fish from the Tanis site


Site(s) Age Location Significance Notable fossils/organisms


60 Ma

Auvergne, France

A Palaeocene maar lake containing three-dimensional plant remains.

Fur Formation

55–53 Ma

Fur & Mors, Denmark

Preserves abundant fossil fish, insects, reptiles, birds and plants. The Fur Formation was deposited about 55 Ma, just after the Palaeocene-Eocene boundary, and its tropical or sub-tropical flora indicate that the climate after the Paleocene-Eocene Thermal Maximum was moderately warm (approximately 4-8 degrees warmer than today).

Tasbacka danica, immature sea turtle

London Clay

54–48 Ma

England, UK

Collected for close to 300 years, Plant fossils, especially seeds and fruits, are found in abundance.
Some 350 named species of plant have been found, making the London Clay flora one of the world's most diverse for fossil seeds and fruits. The flora includes tropical taxa found in modern Asia, reflecting the much warmer climate of the early Eocene.

A Tynskya eocaena fossil

Eocene Okanagan Highlands

52 - 48 Ma

British Columbia, Canada & Washington, USA

Includes McAbee Fossil Beds, Princeton chert & Klondike Mountain Formation; Recognized as temperate/subtropical uplands right after the Paleocene–Eocene Thermal Maximum and spanning the Early Eocene Climatic Optimum, preserves highly detailed uplands lacustrine fauna and flora.

A Florissantia quilchenensis flower, an extinct malvaceous genus from western North America

Green River Formation

50 Ma

Colorado/Utah/Wyoming, US

An Eocene aged site that is noted for the fish fauna preserved. Other fossils include the crocodilians, birds, and mammals.

Diplomystus and Knightia

Monte Bolca

49 Ma

Verona, Italy

A fossil site with specimens of fish and other organisms that are so highly preserved that their organs are often completely intact in fossil form, and even the skin color can sometimes be determined. It is assumed that mud at the site was low in oxygen, preventing both decay and the mixing action of scavengers from harming the fossils.

A complete Archaeophis proavus

Messel Formation

49 Ma

Hessen, Germany

This site has significant geological and scientific importance. Over 1000 species of plants and animals have been found at the site. After almost becoming a landfill, strong local resistance eventually stopped these plans and the Messel Pit was declared a UNESCO World Heritage Site on 9 December 1995. Significant scientific discoveries about the early evolution of mammals and birds are still being made at the Messel Pit, and the site has increasingly become a tourist site as well.

Masillamys sp., an ischyromyid rodent
Kishenehn Formation 46.2 Ma Montana A Middle Eocene site preserving exquisitely detailed insect specimens in oil shale.
Mahenge 46 Ma Tanzania A terrestrial Middle Eocene lagerstätte preserving plant and arthropod fossils.

Quercy Phosphorites Formation

45-25 Ma

South-Western France

This site qualifies as a Lagerstätte because beside a large variety of mammals, birds, turtles, crocodiles, flora and insects, it also preserves the soft tissues of amphibians and squamates, in addition to their articulated skeleton in what has been called natural mummies.

Xenomorphia resurrecta parasitic wasps preserved in fly pupae

Florissant Formation

34 Ma


A late Eocene (Priabonian) aged site that is noted for the finly preserved plant and insect paleobiota. Fossils are preserved in diatom blooms of a lahar dammed lake system and the formation is noted for the petrified stumps of Sequoia affinis

A Palaeovespa florissantia
Rauenberg 30 Ma Baden-Württemberg, Germany A marine fossil site with an Arctic-like invertebrate fauna and a Paratethyan vertebrate fauna displaying evidence of intermittent anoxia.

Enspel Lagerstätte

24.79-24.56 Ma

Rhineland-Palatinate, Germany

A Chattian maar deposit famous for its insect fossils.

Aix-en-Provence ~24 Ma Provence, France A terminal Oligocene brackish palaeoenvironment.


Site(s) Age Location Significance Notable fossils/organisms
Dominican amber 30–10 Ma Dominican Republic Dominican amber differentiates itself from Baltic amber by being nearly always[citation needed] transparent, and it has a higher number of fossil inclusions. This has enabled the detailed reconstruction of the ecosystem of a long-vanished tropical forest.
A larval Amblyomma tick preserved in amber.
Riversleigh 25–15 Ma Queensland, Australia This locality is recognised for the series of well preserved fossils deposited from the Late Oligocene to the Miocene. The fossiliferous limestone system is located near the Gregory River in the north-west of Queensland, an environment that was once a very wet rainforest that became more arid as the Gondwanan land masses separated and the Australian continent moved north.
Reconstruction of the diprotodont marsupial Nimbadon lavarackorum.
Foulden Maar 23 Ma Otago, New Zealand These layers of diatomite have preserved exceptional fossils of fish from the crater lake, and plants, spiders, and insects from the sub-tropical forest that developed around the crater, along with in situ pollen.
The teleost fish species Galaxias effusus.
Chiapas amber 23-15 Ma Chiapas, Mexico As with other ambers, a wide variety of taxa have been found as inclusions including insects and other arthropods, as well as plant fragments and epiphyllous fungi.
The holotype specimen of the millipede Anbarrhacus adamantis.
Clarkia fossil beds 20-17 Ma Idaho, US The Clarkia fossil beds site is best known for its fossil leaves. Their preservation is exquisite; fresh leaves are unfossilized, and sometimes retain their fall colors before rapidly oxidizing in air. It has been reported that scientists have managed to isolate small amounts of ancient DNA from fossil leaves from this site. However, other scientists are skeptical of the validity of this reported occurrence of Miocene DNA.
A leaf fossil from the beds after being exposed to oxygen.
Barstow Formation 19–13.4 Ma California, US The sediments are fluvial and lacustrine in origin except for nine layers of rhyolitic tuff. It is well known for its abundant vertebrate fossils including bones, teeth and footprints. The formation is also renowned for the fossiliferous concretions in its upper member, which contain three-dimensionally preserved arthropods.
A fossilized footprint made by a camel.
Shanwang Formation 18-17 Ma Shandong Province, China Fossils have been found at this site in dozens of categories, representing over 600 separate species. Animal fossils include insects, fish, spiders, amphibians, reptiles, birds and mammals. Insect fossils have clear, intact veins. Some have retained beautiful colours.
Morozaki Group 18-17 Ma Aichi Prefecture, Japan Known from well-preserved deep sea fauna including fish, starfish and arthropods like crabs, shrimps and giant amphiopods.
Sandelzhausen 16 Ma Bavaria, Germany A Middle Miocene vertebrate locality.
McGraths Flat ~16-11 Ma NSW, Australia Deposited in unusual conditions that record microscopic details of soft tissues and delicate structures. Fossil evidence of animals with soft bodies, unlike the bones of mammals and reptiles, is rare in Australia, and discoveries at McGraths' Flat have revealed unknown species of invertebrates such as insects and spiders.
Pisco Formation 15-2 Ma Arequipa & Ica, Peru Several specialists consider the Pisco Formation one of the most important Lagerstätten, based on the large amount of exceptionally preserved marine fossils, including sharks (most notably megalodon), penguins, whales, dolphins, birds, marine crocodiles and aquatic giant sloths.
Reconstruction of the macroraptorial stem-physeteroid whale Acrophyseter.
Hindon Maar 14.6 Ma New Zealand A maar preserving a Southern Hemisphere lake-forest ecosystem, including body fossils of plants, insects, fish, and birds, along with in situ pollen and coprolites of both fish and birds.
Ngorora Formation 13.3-9 Ma Tanzania The alkaline palaeolake deposits of the Ngorora Formation contains articulated fish fossils that died en masse from asphyxiation during episodic ash falls or from rapid acidification.
Pi Gros 13 Ma Catalonia, Spain An ichnofossil lagerstätte containing annelid, mollusc, and sponge trace fossils. The fossil site no longer exists due to having been quarried for the construction of an industrial park.
Bullock Creek 12 Ma Northern Territory, Australia Among the fossils at the Bullock Creek site have been found complete marsupial crania with delicate structures intact. New significant taxa identified from the Bullock Creek mid Miocene include a new genus of crocodile, Baru (Baru darrowi), a primitive true kangaroo, Nambaroo, with high-crowned lophodont teeth; and a new species of giant horned tortoise, Meiolania. New marsupial lion, thylacine, and dasyurid material has also been recovered.
Ashfall Fossil Beds 11.83 Ma Nebraska, US The Ashfall Fossil Beds of Antelope County in northeastern Nebraska are rare fossil sites of the type called lagerstätten that, due to extraordinary local conditions, capture an ecological "snapshot" in time of a range of well-preserved fossilized organisms. Ash from a Yellowstone hotspot eruption 10-12 million years ago created these fossilized bone beds.
A bone-bed containing the fossils of the basal rhino Teleoceras and the three-toed horse Cormohipparion.
Alcoota Fossil Beds 8 Ma Northern Territory, Australia It is notable for the occurrence of well-preserved, rare, Miocene vertebrate fossils, which provide evidence of the evolution of the Northern Territory's fauna and climate. The Alcoota Fossil Beds are also significant as a research and teaching site for palaeontology students.
Miscellaneous fossils of several macropod marsupials
Saint-Bauzile 7.6-7.2 Ma Ardèche, France A Late Miocene site preserving articulated mammal skeletons with skin and fur impressions.
Tresjuncos 6 Ma Cuenca, Spain A Late Miocene lacustrine Konservat-Lagerstätte containing fossils of diatoms, plants, crustaceans, insects, and amphibians.
Gray Fossil Site 4.9-4.5 Ma Tennessee, US As the first site of its age known from the Appalachian region, the Gray Fossil Site is a unique window into the past. Research at the site has yielded many surprising discoveries, including new species of red panda, rhinoceros, pond turtle, hickory tree, and more. The site also hosts the world's largest known assemblage of fossil tapirs.


Site(s) Age Location Significance Notable fossils/organisms
The Mammoth Site 26 Ka South Dakota, US The facility encloses a prehistoric sinkhole that formed and was slowly filled with sediments during the Pleistocene era. As of 2016, the remains of 61 mammoths, including 58 North American Columbian and 3 woolly mammoths had been recovered. Mammoth bones were found at the site in 1974, and a museum and building enclosing the site were established.
Fossil skeleton of Arctodus simus, a large species of "short-faced" bear that was one of North America's largest predators during the Pleistocene
Fossil skeleton of Arctodus simus, a large species of "short-faced" bear that was one of North America's largest predators during the Pleistocene.
Rancho La Brea Tar Pits 40–12 Ka California, US A group of tar pits where natural asphalt (also called asphaltum, bitumen, or pitch; brea in Spanish) has seeped up from the ground for tens of thousands of years. Over many centuries, the bones of trapped animals have been preserved. Among the prehistoric species associated with the La Brea Tar Pits are Pleistocene mammoths, dire wolves, short-faced bears, American lions, ground sloths, and, the state fossil of California, the saber-toothed cat (Smilodon fatalis).
Fossil skeleton of Mammuthus columbi excavated from the tar pits
Waco Mammoth National Monument 65–51 Ka Texas, US A paleontological site and museum in Waco, Texas, United States where fossils of 24 Columbian mammoths (Mammuthus columbi) and other mammals from the Pleistocene Epoch have been uncovered. The site is the largest known concentration of mammoths dying from a (possibly) reoccurring event, which is believed to have been a flash flood.
Fossil skeleton of a mammoth found at the Waco site
El Breal de Orocual 2.5–1 Ma Monagas, Venezuela The largest asphalt well on the planet. Like the La Brea Tar Pits, this site preserves a number of megafauna like toxodonts, glyptodonts, camelids, and the felid Homotherium venezuelensis.
Restoration of the environment at El Breal de Orocual, showing Glyptodon, Coragyps, Dasypus and Myrmecophaga
El Mene de Inciarte 28-25.5 Ka Zulia, Venezuela Another series of tar pits. These also preserve a similar assemblage of megafauna.
Naracoorte Caves 500-1 Ka South Australia, Australia A series of caves that preserve numerous pleistocene megafauna, like Thylacoleo, and is recognized as a World heritage site alongside the older, but geographically similar Riversleigh site.
Skeleton of Thylacoleo at the Naracoorte Caves

See also

  • List of fossil sites (with link directory)
  • Hoard, a concentration of human artifacts useful for similar reasons in archaeology

This page was last updated at 2023-11-12 10:09 UTC. Update now. View original page.

All our content comes from Wikipedia and under the Creative Commons Attribution-ShareAlike License.


If mathematical, chemical, physical and other formulas are not displayed correctly on this page, please useFirefox or Safari