Assemblage 4B (Ordovician of the United Kingdom)

Also known as Dwyfor Mudstone fauna, North Wales Rawtheyan Assemblage 4B, England

Where: England, United Kingdom (53.0° N, 4.0° W: paleocoordinates 45.6° S, 17.8° W)

• local area-level geographic resolution

When: Dwyfor Mudstone Formation, Rawtheyan (448.8 - 445.2 Ma)

• formation-level stratigraphic resolution

Environment/lithology: submarine fan; lithified shale

• Tough, blocky, dark grey mudstone

Size class: macrofossils

Primary reference: D. Price. 1981. Ashigill trilobite faunas from the Llyn Peninsula, North Wales, U.K. Geological Magazine 16(3):201-216 [A. Miller/P. Novack-Gottshall]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 3671: authorized by Arnold Miller, entered by Phil Novack-Gottshall on 06.08.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Pterobranchia
 Graptoloidea - Diplograptidae
Orthograptus sp.
Orthograptus sp. Lapworth 1873 graptolite
originally entered as "Orthograotus sp."
 Lophophorata -
Tentaculitida indet.
Tentaculitida indet. Ljaschenko 1955
Strophomenata
 Strophomenida - Christianiidae
Christiania sp.
Christiania sp. Hall and Clarke 1892
 Strophomenida - Leptestiidae
Leptestiina sp.
Leptestiina sp. Opik 1933
 Strophomenida - Foliomenidae
Foliomena sp.
Foliomena sp. Havlicek 1952
Trilobita
 Trinucleida - Raphiophoridae
Raphiophorus sp., Lonchodomas sp.
Raphiophorus sp. Angelin 1854 trilobite
Lonchodomas sp. Angelin 1854 trilobite
 Trinucleida - Trinucleidae
Nankinolithus sp.
Nankinolithus sp. Lu 1957 trilobite
 Trinucleida - Dionididae
Dionide sp.
Dionide sp. Barrande 1847 trilobite
 Asaphida - Asaphidae
Opsimasaphus sp.
Opsimasaphus sp. Kielan 1960 trilobite
 Asaphida - Remopleurididae
Amphitryon sp.
Amphitryon sp. Hawle and Corda 1874 trilobite
 Asaphida - Cyclopygidae
Cyclopyge sp., Microparia sp., Symphysops sp.
Cyclopyge sp. Hawle and Corda 1847 trilobite
Microparia sp. Hawle and Corda 1847 trilobite
Symphysops sp. Raymond 1925 trilobite
 Lichida - Lichidae
? Platylichas sp.
? Platylichas sp. Gürich 1901 trilobite
originally entered as "Platylichas? sp."
 Phacopida - Pterygometopidae
Liocnemis sp.
Liocnemis sp. Kielan 1960 trilobite
 Phacopida - Dalmanitidae
Duftonia sp.
Duftonia sp. Dean 1959 trilobite
 Phacopida - Calymenidae
Gravicalymene sp.
Gravicalymene sp. Shirley 1936 trilobite
 Phacopida - Encrinuridae
Paracybeloides sp., Dindymene sp.
Paracybeloides sp. Hupé 1955 trilobite
Dindymene sp. Hawle and Corda 1847 trilobite
 Phacopida - Cheiruridae
Pseudosphaerexochus sp., ? Sphaerocoryphe sp.
Pseudosphaerexochus sp. Schmidt 1881 trilobite
? Sphaerocoryphe sp. Angelin 1854 trilobite
originally entered as "Sphaerocoryphe? sp."
 Corynexochida - Styginidae
Phillipsinella sp.
Phillipsinella sp. Novak 1885 trilobite
 Corynexochida - Illaenidae
Illaenus sp.
Illaenus sp. Dalman 1827 trilobite
 Proetida - Proetidae
Paraproetus sp.
Paraproetus sp. Kobayashi and Hamada 1979 trilobite
Artiopoda
 Agnostida - Sphaeragnostidae
Sphaeragnostus sp.
Sphaeragnostus sp. Cooper and Kindle 1936
 Agnostida - Metagnostidae
Arthrorhachis sp.
Arthrorhachis sp. Hawle and Corda 1847