Layer 8 (Ordovician of the United States)

Where: New York (43.3° N, 75.1° W: paleocoordinates 27.5° S, 53.1° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Orthograptus ruedemanni graptolite zone, Spillway Member (Rust Formation), Chatfieldian (453.8 - 451.0 Ma)

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, tabular, burrowed lime mudstone

• This unit consists primarily of a tabular calcilutite or micrite and is commonly amalgamated to a lower hash bed...highly burrowed with some burrows extending to the base

Size class: macrofossils

Collected by Thomas E. Whiteley in 1990-1999; reposited in the MCZ

Collection methods: surface (in situ), mechanical,

Primary reference: C. E. Brett, T. E. Whiteley, P. A. Allison and E. L. Yochelson. 1999. The Walcott-Rust Quarry: Middle Ordovician Trilobite Konservat-Lagerst├Ątten. Journal of Paleontology 73(2):288-305 [M. Hopkins/M. Hopkins/M. Hopkins]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 181522: authorized by Melanie Hopkins, entered by Melanie Hopkins on 15.09.2016

Creative Commons license: CC BY (attribution)

Taxonomic list

 Conulariida - Conchopeltidae
 Phacopida - Cheiruridae
Ceraurus pleurexanthemus Green 1832 trilobite
originally Ceraurus pleurecanthemus
 Phacopida - Pterygometopidae
Calyptaulax callicephalus Hall 1847 trilobite
Achatella achates Billings 1860 trilobite
 Phacopida - Calymenidae
 Corynexochida - Illaenidae
"Nanillaenus americanus" = Thaleops laurentiana
"Nanillaenus americanus" = Thaleops laurentiana Amati and Westrop 2004 trilobite
 Asaphida - Asaphidae
Isotelus gigas Dekay 1824 trilobite
 Asaphida - Remopleurididae
Hypodicranotus striatulus Walcott 1875 trilobite