Beecher's Trilobite Bed is a Konservat-Lagerstätte of Late

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...

(Caradoc) age located within the Frankfort Shale in Cleveland's Glen,

Oneida County, New York Oneida County ( ) is a county in the state of New York, United States. As of February 26, 2024, the population was 226,654. The county seat is Utica. The name is in honor of the Oneida, one of the Five Nations of the Iroquois League or '' ...

, USA.Martha Buck's senior thesis on the Beecher's Trilobite Bed
Photos (and more) of trilobites from Beecher's Trilobite Bed from Yale Peabody Museum
Only 3–4 centimeters thick, Beecher's Trilobite Bed has yielded numerous exceptionally preserved

trilobite Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most succ ...

s with the ventral anatomy and soft tissue intact, the soft tissue preserved by

pyrite The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue ...

replacement. Pyritisation allows the use of X-rays to study fine detail of preserved soft body parts still within the host rock. Pyrite replacement of soft tissue is unusual in the fossil record; the only Lagerstätten thought to show such preservation were Beecher's Trilobite Bed, the Devonian Hunsrück Slates of Germany, and the Jurassic beds of La Voulte-sur-Rhône in France, although new locations are coming to light in New York state.

History of research

Originally discovered in 1892 by William S. Valiant, the site was thoroughly excavated from 1893 to 1895 by Charles Emerson Beecher (after whom the location is named) of

Yale University Yale University is a Private university, private Ivy League research university in New Haven, Connecticut, United States. Founded in 1701, Yale is the List of Colonial Colleges, third-oldest institution of higher education in the United Stat ...

, after which time the location was thought to be exhausted of fossils and excavations ceased. Beecher published three papers describing a trilobite larval form, trilobite limbs and trilobite ventral anatomy from material collected from the site he established. Beecher died unexpectedly in 1904; much material, as well as details of the location, was lost. Research was subsequently limited to study of material collected during the original excavations that had been distributed to various institutions. Amateur fossil collectors Tom E. Whiteley (also responsible for rediscovering the Walcott-Rust quarry) and Dan Cooper rediscovered the location in 1984 and from 1985 academic excavations and studies (re)-commenced. At least 4 other fossil-bearing horizons exhibiting similar preservation have subsequently been found at the original site. The small quarry at the site is currently closed to public access,Forum talk regarding quarry access.
being on private land and administered by Yale Peabody Museum as part of ongoing research projects.Yale Peabody (Briggs Laboratory) research projects.

Sedimentology, environment of deposition and preservation

The original Beecher's Trilobite Bed is found within a thick succession of fine grained

turbidite A turbidite is the geologic Deposition (geology), deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean. Sequencing ...

beds, the fossiliferous bed is about 40 mm thick lying on a scoured mudstone surface with remnants of burrows. Well preserved fossil remains are found 7–10 mm above the base parallel to the bedding plane, strongly aligned by the current, with as many facing up as down. Chemically, the bed contains high iron coupled with low organic carbon and low organic sulfur. The ecosystem of the Beecher's Trilobite bed most likely inhabited very deep water, and has been compared to the various deep water faunas inhabiting enclosed basins off the coast of southern

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. The depth of the area is indicated by the presence of blind animals, including the trilobite '' Cryptolithus'', and the majority of the other taxa known occupying deposit and

suspension feeding Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a specia ...

niches. The presence of turbidite beds in the surrounding sediments also adds evidence to this theory, as they are often deposited in deep water areas. The main source of food in the ecosystem would've been

marine snow In the deep ocean, marine snow (also known as "ocean dandruff") is a continuous shower of mostly organic detritus falling from the upper layers of the water column. It is a significant means of exporting energy from the light-rich photic zone to ...

, and other various organic material floating downward from shallower areas. The environment would've also been dysaerobic, which may have aided in killing the organisms before they were buried by sediments via turbidity currents.

Fauna

The fauna of the site included various trilobites, megacheirans,

graptolites Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian (Miaolingian, Wuliuan) through th ...

brachiopods Brachiopods (), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the fron ...

nautiloids Nautiloids are a group of cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and ''Allonautilus''. Fossil nautiloids are diverse and species rich, with over 2,500 recorded species. Th ...

, ostracods, poriferans,

bryozoans Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic animal, aquatic invertebrate animals, nearly all living in sedentary Colony (biology), colonies. Typically about long, they have a spe ...

annelids The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to vario ...

, phyllocarids,

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

, and

echinoderms An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as larv ...

. The trilobite ''

Triarthrus eatoni ''Triarthrus'' is a genus of Upper Ordovician ptychopariida, ptychopariid trilobite found in New York (state), New York, Ohio, Kentucky, and Indiana, eastern and northern Canada, China and Scandinavia. It is the last of the Olenid trilobites, a g ...

'' comprises 85% of the organisms sampled at the locality, other notable taxa include graptolites, branching algae, brachiopods and problematica (''

incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

''). The trilobites ''Cryptolithus bellulus'' (Ulrich), '' Cornuproetus beecheri'' (Ruedeman), '' Primaspis crosotus'' (Locke) are also recorded. In addition, the megacheiran ''

Lomankus ''Lomankus'' is an extinct genus of megacheiran (great appendage) arthropod known from the upper Ordovician aged Beecher's Trilobite Bed, within the larger Frankfort shale in the state of New York (state), New York. A single species is known, ''L ...

'' is known from the site.

References

External links

Peabody Museum of Natural History, Yale University
(official website)
Yale Environmental News article with site pictures, see page 9
{{Cambrian preservational modes Paleozoic paleontological sites of North America Ordovician paleontological sites Trilobites of North America Lagerstätten Geologic formations of New York (state) Paleontology in New York (state) Shale formations of the United States

History of research

Sedimentology, environment of deposition and preservation

Fauna

See also

References

External links