Gydo Formation (1st Shale), Clanwilliam (Devonian of South Africa)

Where: South Africa (32.2° S, 18.9° E: paleocoordinates 61.5° S, 148.2° W)

• coordinate stated in text

• local area-level geographic resolution

When: Gydo Formation (Bokkeveld Group), Emsian (407.6 - 393.3 Ma)

• Age call from ref. 9618

• formation-level stratigraphic resolution

Environment/lithology: marine; bioturbated mudstone and bioturbated siltstone

• Ref. 9618 gives interpretation of Bokkeveld Group as a series of shallowing-upward packages, with argillaceous unit below and arenaceous unit above. Gydo Formation, as the "first shale", is the lowermost argillaceous unit. The shallowing upward sequence is interpreted as representing environments from the shelf up to deltaic systems. Most fossils come from lower mudstones, often in lenses.
• Ref. 9616 refers only to "shale". Ref. 9617, for formation as a whole, cites "Mudstones and siltstones and minor thin-bedded sandstone, scattered fossiliferous nodules and lenses, lenticular bedding, abundant bioturbation."

Collection methods: Author gives numbers from personal collections, which are said to have some bearing on actual abundances.

Primary reference: R. D. F. Oosthuizen. 1984. Preliminary catalogue and report on the biostratigraphy and palaeogeographic distribution of the Bokkeveld fauna. Transactions of the Geological Society of South Africa 87:125-140 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 35587: authorized by Michael Foote, entered by Michael Foote on 29.12.2003

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Bivalvia
 Nuculanida - Cucullellidae
Nuculites obtusus
 Nuculanida - Nuculanidae
"Nuculana" "sp. (c)"
"Nuculana" "sp. (c)" Link 1807 pointed nut clam
Gastropoda
 Bellerophontida - Tropidodiscidae
"Bellerophon cf. globosus" = Tropidodiscus globosus
"Bellerophon cf. globosus" = Tropidodiscus globosus Knod 1908 snail
 Bellerophontida - Plectonotidae
"Bellerophon africanoides" = Ptomatis africanoides
"Bellerophon africanoides" = Ptomatis africanoides Reed 1925 snail
 Bellerophontida - Bellerophontidae
Bellerophon "sp. (a)"
Bellerophon "sp. (a)" de Montfort 1808 snail
Hyolitha
 Hyolithida - Hyolithidae
Hyolithes subaequalis
Rhynchonellata
 Terebratulida - Meganterididae
Mutationella whitiorum, Derbyina "sp. (a)", Derbyina "sp. (b)"
Lingulata
 Lingulida - Discinidae
Orbiculoidea baini
Stenolaemata
 Cryptostomata - Fenestellidae
Fenestella "sp. (c)"
Fenestella "sp. (c)" Lonsdale 1839
Lophophorata
 Tentaculitida - Tentaculitidae
Tentaculites crotalinus
 Tentaculitida - Cornulitidae
Cornulites "sp. (a)"
Cornulites "sp. (a)" Schlotheim 1820
Trilobita
 Phacopida - Calmoniidae
Oosthuizenella ocellus, Pennaia pupillus, "Metacryphaeus caffer" = Metacryphaeus (Metacryphaeus) caffer
Pennaia pupillus trilobite
"Metacryphaeus caffer" = Metacryphaeus (Metacryphaeus) caffer Salter 1856 trilobite
 Phacopida - Homalonotidae
Burmeisteria herscheli
Stylophora
 Mitrata - Australocystidae
Placocystella capensis