USNM9271, Block 4, Ko Muk Island northeast (Permian of Thailand)

Where: Trang, Thailand (7.4° N, 99.3° E: paleocoordinates 31.3° S, 107.5° E)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Rat Buri Formation, Roadian (272.3 - 268.8 Ma)

• Blocks are derived from seacliffs, making it impossible to measure a stratigraphic section or determine whether they are derived from a single horizon. The age of the Rat Buri fauna is problematic. "Rat Buri" limestones likely range in age from Kungurian through Capitanian to perhaps Wuchiapingian. Wordian fusulinids appear most common in other collections, but are not found in association with the brachiopod localities. The brachopod fauna is most similar to the Wordian Amb Formation of the Salt Range, in Pakistan, tentatively indicating a Wordian age.

• group of beds-level stratigraphic resolution

Environment/lithology: offshore shelf; lithified, argillaceous, sandy limestone

• Interpreted as rather quiet water that was deep enough not to be disrupted by ordinary wave action. It was a fairly flat sea floor bearing an abundant fauna of small organisms with bryozoans and crinoids in patches like gardens.

Size class: macrofossils

Preservation: replaced with silica

Collection methods: bulk, surface (float), chemical,

Primary reference: R. E. Grant. 1976. Permian brachiopods from southern Thailand. Paleontological Society Memoir 9:1-269 [D. Bottjer/M. Clapham/M. Clapham]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 40873: authorized by David Bottjer, entered by Matthew Clapham on 02.07.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Concentrates on brachiopods, and other groups are listed only in the text for the generic total collection, not for the subset individual blocks.
Strophomenata
 Productida - Productellidae
Dyschrestia spodia Grant 1976
Celebetes leptus Grant 1976
 Productida - Productidae
 Productida - Anopliidae
 Productida - Rugosochonetidae
"Chonetinella cymatilis" = Neochonetes (Sommeriella) cymatilis
"Chonetinella cymatilis" = Neochonetes (Sommeriella) cymatilis Grant 1976
 Productida - Rigbyellidae
Paralyttonia tenax Grant 1976
 Orthotetida - Derbyiidae
Derbyia scobina Grant 1976
 Orthotetida - Meekellidae
Meekella addicta Grant 1976
Rhynchonellata
 Athyridida - Neoretziidae
Hustedia ratburiensis Waterhouse and Piyasin 1970
 Athyridida - Athyrididae
 Spiriferinida - Paraspiriferinidae
 Spiriferida - Spiriferellidae
 Spiriferida - Ambocoeliidae
Cruricella couria Grant 1976
 Spiriferida - Elythidae
 Rhynchonellida - Allorhynchidae