Beecher's Trilobite Bed is a
Konservat-Lagerstätte of Late
Ordovician
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. ...
(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 the 2020 census, the population was 232,125. The county seat is Utica. The name is in honor of the Oneida, one of the Five Nations of the Iroquois League or ''Haudenosa ...
, 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 lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the ...
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 giv ...
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 research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the List of Colonial Colleges, third-oldest institution of higher education in the United Sta ...
, 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[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 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
Turbidites w ...
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.][
]
Fauna
The trilobite '' Triarthrus eatoni'' comprises 85% of the organisms sampled at the locality, other taxa include graptolite
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 the L ...
s, branching algae, brachiopods and problematica (''incertae sedis
' () or ''problematica'' is a term used for a 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, uncertain ...
'').Cryptolithus bellulus
''Cryptolithus'' is a genus of extinct trinucleid trilobites that lived during the Ordovician period. They were mostly blind. They are found in the United States, Canada, Venezuela, the United Kingdom, France, the Czech Republic, Morocco and Tu ...
'' (Ulrich), '' Cornuproetus beecheri'' (Ruedeman), '' Primaspis crosotus'' (Locke) are also recorded.
See also
* Beecher's Trilobite type preservation, the preservational pathway responsible
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)