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

Where: South Africa (32.6° S, 19.4° E: paleocoordinates 60.9° S, 148.7° 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 35584: authorized by Michael Foote, entered by Michael Foote on 29.12.2003

Creative Commons license: CC BY (attribution)

Taxonomic list

 Phacopida - Calmoniidae
 Phacopida - Homalonotidae
 Cardiidia - Sanguinolitidae
 Cardiidia - Grammysiidae
 Protobranchia - Malletiidae
 Euomphalina - Platyceratidae
""Diaphorostoma" baini" = Platyceras (Platyostoma)
""Diaphorostoma" baini" = Platyceras (Platyostoma) snail
 Bellerophontida - Plectonotidae
"Bellerophon cf. laticarinatus" = Plectonotus laticarinata, "Bellerophon africanoides" = Ptomatis africanoides
"Bellerophon cf. laticarinatus" = Plectonotus laticarinata Knod 1908 snail
"Bellerophon africanoides" = Ptomatis africanoides Cowper Reed 1925 snail
 Murchisoniina - Palaeozygopleuridae
"Loxonema zwartbergense" = Pragozyga zwartbergense
"Loxonema zwartbergense" = Pragozyga zwartbergense Cowper Reed 1925 snail
 Trepostomata -
Acanthodii indet. Owen 1846 spiny fish
acanthodian spines
Crinoidea indet. Miller 1821 Sea lily
 Diplobathrida -
 Tentaculitida - Tentaculitidae
Brachiopoda indet. Cuvier 1805
 Productida - Chonetidae
 Orthotetida - Pulsiidae
 Strophomenida - Strophodontidae
"Strophodonta ? arcei" = Strophomena (Strophodonta)
"Strophodonta ? arcei" = Strophomena (Strophodonta)
 Terebratulida - Centronellidae
 Terebratulida - Meganterididae
 Spiriferida - Acrospiriferidae
 Spiriferida - Hysterolitidae
 Rhynchonellida - Leptocoeliidae
 Lingulida - Disciniidae
 Lingulida - Lingulidae
 Conulariida - Conulariidae