Threadgill Creek section (San Saba Limestone) (Cambrian of the United States)

Also known as Llano Uplift

Where: Gillespie County, Texas (30.5° N, 99.1° W: paleocoordinates 17.7° S, 95.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: San Saba Limestone Member (Wilberns Formation), Trempealeauan (501.0 - 485.4 Ma)

• Some of the specimens are said to come "from the cephalopod bed, now closer to 30 feet than 67 feet, the previous estimate, below the top of the San Saba limestone" (p. 31) but other specimens no exact stratigrapic position is given for. "Trempealeauan San Saba limestone" (e.g.,caption of plate 4). The San Saba Limestone belongs to the Wilberns Fm. (e.g. Bridge et al., 1947, Bull. GSA 58).

• member-level stratigraphic resolution

Environment/lithology: shallow subtidal; ooidal, shelly/skeletal grainstone

Size class: macrofossils

Preservation: cast, replaced with calcite, replaced with pyrite

Reposited in the USNM

• RHF = collection of Rousseau H. Flower, transferred to the Smithsonian Institution/U.S. National Museum (see Wolberg, 1990, J. Paleont. 64(3, 5, 6))

Primary reference: R. H. Flower. 1964. The Nautiloid Order Ellesmeroceratida (Cephalopoda). State Bureau of Mines and Mineral Resources New Mexico Institute of Mining and Technology, Memoir 12:234 p. [B. Kröger/T. Liebrecht/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 88784: authorized by Björn Kröger, entered by Torsten Liebrecht on 20.04.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

• In explanation of plate 3 the holotype of Balkoceras gracile is said to be no. 311 of the writers collection. In the text (pp. 34, 35) it is said the holotype of B. gracile is no. 307 of the writers colletion, but no. 307 is also said to be one of the hypotype specimens of Palaeoceras mutabile.
Cephalopoda
 Ellesmerocerida - Ellesmeroceratidae
Ectenolites primus n. sp. Flower 1964
RHF 298 (type)
Ectenolites aff. primus Flower 1964
RHF 299
 Ellesmerocerida - Balkoceratidae
Balkoceras gracile n. gen. n. sp.
Balkoceras gracile n. gen. n. sp. Flower 1964
RHF 307 (holotype); 308-310 (paratypes)
 Ellesmerocerida - Plectronoceratidae
Plectronoceras exile n. sp. Flower 1964
RHF 303 (type)
Palaeoceras mutabile n. gen. n. sp. Flower 1954
2 specimens in the collections of the Bureau of Economic Geology, University of Texas (holotype + paratype); RHF 304-307 (all are hypotypes)
Palaeoceras undulatum n. sp. Flower 1964
RHF 300 (holotype); 301, 302 (paratypes)