Guichen (Ordovician of France)

Also known as Gres Armoricain Fm., Guichen, Ille-et-Vilaine

Where: Ille-et-Vilaine, France (48.0° N, 2.0° W)

• Paleocoordinates: 77.4° S, 25.7° W (Wright 2013)

• coordinate estimated from map

• local area-level geographic resolution

When: Superieur Member (Grès Armoricain Formation), Arenig (478.6 - 466.0 Ma)

• member-level stratigraphic resolution

Environment/lithology: transition zone or lower shoreface; lithified sandstone and lithified shale

• Sandstone occasionally intercalated with shale

Size class: macrofossils

Primary reference: C. Babin. 1966. Mollusques bivalves et céphalopodes du Paléozoïque Armoricain. Étudé systématique. Essai sur la phylogénie des bivalves. Esquisse paléoécologique. Imprimerie Commerciale et Administrative. Brest 1-471 [A. Miller/P. Novack-Gottshall/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 20860: authorized by Arnold Miller, entered by Phil Novack-Gottshall on 11.06.2002, edited by Pete Wagner

Creative Commons license: CC0 (CC0)

Taxonomic list

• Bivalve taxonomy and biostratigraphy
Bivalvia
 Nuculanida - Cucullellidae
 Nuculanida - Nuculanidae
"? Leda sp." = Nuculana
"? Leda sp." = Nuculana Link 1807 pointed nut clam
 Nuculida - Praenuculidae
Synek antiquus Barrande 1881 clam
 Unioni - Lyrodesmatidae
"Lyrodesma armoricana" = Tromelinodonta armoricana
"Lyrodesma armoricana" = Tromelinodonta armoricana de Tromelin and Lebesconte 1875 clam
 Actinodontida - Cycloconchidae
 Modiomorphida - Modiomorphidae
? Hippomya salteri Barrois 1891 clam