Threadgill Creek section (San Saba Limestone): Trempealeauan, Texas

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Cephalopoda - Ellesmerocerida - Balkoceratidae
Balkoceras gracile n. gen., n. sp. Flower 1964
4 specimens
RHF 307 (holotype); 308-310 (paratypes)
Cephalopoda - Ellesmerocerida - Plectronoceratidae
Plectronoceras exile n. sp. Flower 1964
1 specimen
RHF 303 (type)
Palaeoceras mutabile n. gen., n. sp. Flower 1954
6 specimens
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
3 specimens
RHF 300 (holotype); 301, 302 (paratypes)
Cephalopoda - Ellesmerocerida - Ellesmeroceratidae
Ectenolites primus n. sp. Flower 1964
1 specimen
RHF 298 (type)
Ectenolites aff. primus Flower 1964
1 specimen
RHF 299
see common names

Geography
Country:United States State/province:Texas County:Gillespie
Coordinates: 30.5° North, 99.1° West (view map)
Paleocoordinates:17.7° South, 95.8° West
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period: Cambrian Epoch: Furongian
10 m.y. bin: Cambrian 5
Key time interval: Trempealeauan
Age range of interval: 489.2 - 485.4 m.y. ago
Stratigraphy
Geological group:Moore Hollow Formation:Wilberns Member:San Saba Limestone
Stratigraphic resolution:member
Stratigraphy comments: 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).
Lithology and environment
Primary lithology:ooidal,shelly/skeletal grainstone
Includes fossils?Y
Environment:shallow subtidal indet. Tectonic setting:passive margin
Taphonomy
Modes of preservation:body,cast,replaced with calcite,replaced with pyrite
Size of fossils:macrofossils
Temporal resolution:time-averaged
Spatial resolution:autochthonous
Collection methods and comments
Reason for describing collection:taxonomic analysis
Museum repositories:USNM
Collection method comments: RHF = collection of Rousseau H. Flower, transferred to the Smithsonian Institution/U.S. National Museum (see Wolberg, 1990, J. Paleont. 64(3, 5, 6))
Taxonomic list comments: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.
Metadata
Also known as:Llano Uplift
Database number:88784
Authorizer:B. Kröger Enterer:T. Liebrecht
Modifier:T. Liebrecht Research group:marine invertebrate
Created:2009-04-20 15:41:10 Last modified:2009-04-26 12:02:22
Access level:the public Released:2009-04-20 15:41:10
Creative Commons license:CC BY
Reference information

Primary reference:

29768. 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]