Gelli-grîn Calcareous Ash trilobites, middle beds (Ordovician of the United Kingdom)

Where: Wales, United Kingdom (52.9° N, 3.6° W: paleocoordinates 49.0° S, 17.9° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Dicranograptus caudatus graptolite zone, Upper Member (Gelli-grîn Formation), Woolstonian (457.2 - 454.0 Ma)

• Calcarous Ashes. higher part of calcareous ashes below Cymerig Limestone.

• member-level stratigraphic resolution

Environment/lithology: marine; calcareous ash and blue mudstone

• Calcareous ashes weathering buff with subsidiary dark blue ashy. [Bassett et al 1966, Quart J Geol Soc 122: 219-271]

Size class: macrofossils

Preservation: mold/impression

Reposited in the BMNH

Primary reference: H. B. Whittington. 1968. The Ordovician trilobites of the Bala Area, Merioneth. Part IV. Monograph of the Palaeontographical Society 122(520):93-138 [M. Hopkins/M. Hopkins]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 188591: authorized by Melanie Hopkins, entered by Melanie Hopkins on 08.09.2017

Creative Commons license: CC BY (attribution)

Taxonomic list

 Phacopida - Acastidae
Kloucekia apiculata McCoy 1851 trilobite
 Phacopida - Pterygometopidae
"Chasmops cambrensis" = Scopelochasmops cambrensis
"Chasmops cambrensis" = Scopelochasmops cambrensis Whittington 1962 trilobite
 Phacopida - Encrinuridae
Cybellela dentata Esmark 1833 trilobite
Deacybele pauca Whittington 1965 trilobite
 Phacopida - Homalonotidae
Brongniartella minor Salter 1852 trilobite
 Phacopida - Calymenidae
Flexicalymene cf. caractaci Salter 1865 trilobite
 Trinucleida - Trinucleidae
Broeggerolithus nicholsoni Reed 1910 trilobite
 Lichida - Lichidae
Amphilichas sp., "Platylichas nodulosus" = Allolichas nodulosus, "Conolichas melmerbiensis" = Otarozoum melmerbiensis
Amphilichas sp. Raymond 1905 trilobite
"Platylichas nodulosus" = Allolichas nodulosus McCoy 1851 trilobite
"Conolichas melmerbiensis" = Otarozoum melmerbiensis Reed 1907 trilobite
 Proetida - Otarionidae
Otarion sp. Zenker 1833 trilobite
 Proetida - Tropidocoryphidae
"Astroproetus cf. fearnsidesi" = Decoroproetus fearnsidesi
"Astroproetus cf. fearnsidesi" = Decoroproetus fearnsidesi Bancroft 1949 trilobite