Silica Formation Unit 9A (Devonian of the United States)

Where: Ohio (41.7° N, 83.7° W: paleocoordinates 36.4° S, 31.0° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Silica Formation, Givetian (387.7 - 382.7 Ma)

• group of beds-level stratigraphic resolution

Environment/lithology: marine; gray, blue, argillaceous limestone

• Overall sequence: Bioclastic limestone; argillaceous limestone; shale. This unit: "limestone, argillaceous at base to very argillaceous at top, blue-gray, abundant marcasite concretions, weathering to sticky clay when wet. Very fossiliferous, producing most of the common Silica species"

Primary reference: R. V. Kesling and R. B. Chilman. 1975. Strata and megafossils of the Middle Devonian Silica Formation. University of Michigan Papers on Paleontology 8:1-408 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 38459: authorized by Michael Foote, entered by Michael Foote on 21.04.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

Trilobita
 Phacopida - Phacopidae
"Phacops rana" = Eldredgeops rana
"Phacops rana" = Eldredgeops rana Green 1832 trilobite
 Proetida - Proetidae
Malacostraca
 Archaeostraca -
Bivalvia
 Myalinida - Ambonychiidae
 Pectinida - Pterinopectinidae
 Ostreida - Pterineidae
 Cardiidia - Grammysiidae
 Modiomorphida - Modiomorphidae
 Lucinida - Mactromyidae
Gastropoda
 Euomphalina - Platyceratidae
"Platyceras (Platyostoma) cf. lineatum" = Platyostoma lineata Conrad 1842 snail
Tentaculita
 Styliolinida - Styliolinidae
Cephalopoda
 Orthocerida - Geisonoceratidae
Protokionoceras sp. Grabau and Shimer 1910
 Bactritida - Bactritidae
 Goniatitida - Tornoceratidae
Gymnolaemata
 Ctenostomata - Ascodictyidae
Stenolaemata
 Cyclostomata - Hederellidae
 Cyclostomata -
 Cystoporida - Sulcoreteporidae
 Cystoporida - Fistuliporidae
 Cryptostomata - Arthrostylidae
 Cryptostomata - Hyphasmoporidae
 Trepostomata - Atactotoechidae
 Trepostomata -
 Rhabdomesida - Nikiforovellidae
 Cystoporata -
Crinoidea
 Monobathrida -
Lophophorata
 Tentaculitida - Tentaculitidae
Strophomenata
 Productida - Chonetidae
 Strophomenida - Leptostrophiidae
 Strophomenida - Strophodontidae
"Strophodonta "demissa"" = Strophodonta (Strophodonta) demissa Conrad 1842
Rhynchonellata
 Terebratulida - Cranaenidae
 Spiriferinida - Cyrtinidae
 Spiriferida - Spinocyrtiidae
"Brachyspirifer audaculus" = Mediospirifer audaculus
"Brachyspirifer audaculus" = Mediospirifer audaculus Conrad 1842
 Spiriferida - Ambocoeliidae
 Spiriferida - Mucrospiriferidae
 Spiriferida - Hysterolitidae
 Rhynchonellida - Leiorhynchidae
Anthozoa
 Auloporida - Auloporidae
 Cystiphyllida - Cystiphyllidae
 Stauriida - Amplexidae