Locality FA (Choza Fm.) Main site: Leonardian, Texas
collected by E. C. Olson 1949

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Dipnoi - Gnathorhizidae
Gnathorhiza dikeloda Olson 1951
Molgophidae
Lysorophus tricarinatus Cope 1877
synonym of Brachydectes newberryi
Amphibia - Diplocaulidae
Diplocaulus recurvatus Olson 1952
Amphibia - Temnospondyli - Trimerorhachidae
Trimerorhachis sp. Cope 1878
see common names

Geography
Country:United States State/province:Texas County:Foard
Coordinates: 33.8° North, 99.6° West (view map)
Paleocoordinates:2.2° North, 29.0° West
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
Period:Permian Epoch:Cisuralian
10 m.y. bin:Permian 2
Key time interval:Leonardian
Age range of interval:286.10000 - 273.01000 m.y. ago
Stratigraphy
Geological group:Clear Fork Formation:Choza
Stratigraphy comments: Lower part of the Choza Fm.
Lithology and environment
Primary lithology:red or brown "shale"
Includes fossils?Y
Lithology description: "The deposits at the 'pipe site' are extremely interesting and unlike those encountered anywhere else in the Wichita or Clear Fork sections. The bed from which the fossils come is a deep red shale, exposed on a series of hills over an area about an eighth of a mile on each side. This bed is capped in many places by a thin, dense siltstone. Overlying the siltstone is an orange-red shale that carries gypsum biscuits. Underlying the producing layer, which averages about four feet in thickness, is a brownish-red shale that is devoid of fossils. The most distinctive feature of the bone-bearing shale, outside of the fact that it has fossils, is the occurrence of two types of vertically oriented ovoid structures. One type consists of mottled red and green, hard nodules that range from one to four inches in maximum diameter and up to eighteen inches in length. They are rich in vertebrate remains. They appear to have formed around the bones after deposition, presumably as a result of the reducing action of organic materials. Their vertical orientation is somewhat puzzling. The contained vertebrate remains are usually oriented with their long axes vertical, and it seems quite certain that this position was attained after the formation of the nodules. Specimens of vertebrates free in the shale rather than in nodules are orientated with their long axes horizontal and have been subjected to considerable distortion and breakage. The most reasonable suggestion seems to be that the vertical orientation of the nodules was developed during compaction of the shales, which has been extensive, with the long axes shifting to become normal to the compacting forces. The other vertical structures [...] have been termed pipes and have given the name to the site. They pass from the base to the top of the fossiliferous bed and, at the top, are continuous with the siltstone layer that caps the bed. Their composition is similar to the capping siltstone. The pipes are oval in cross section with maximum diameters from about four to twelve inches. Orientation of the long diameters is random, even in the 'clumps' in which the pipes tend to occur. These structures do not contain vertebrates, although specimens are found 'plastered' to their sides and occasionally penetrating the pipe for a short distance. The origin of the pipes is by no means certain. It is thought that they were formed in open holes by the introduction of the sediment that formed the siltstone layer. Superficially, they resemble lungfish burrows of the Arroyo and Vale (Romer and Olson, 1954), but the shape, size, composition, weathering, and fossil content differ. The most probable explanation is that these openings were formed by the root-like shafts of some type of plant, possibly some Equisetales, that rotted to leave openings that were later filled by sediment. There is no question that the red shales surrounding the pipes were deposited in a shallow pond, and such a pond might well have provided suitable habitat for the type of vegetation envisaged." (Olson, 1955 pp. 60-63)
Environment:pond Tectonic setting:foreland basin
Taphonomy
Modes of preservation:body,concretion
Size of fossils:macrofossils
Preservation of anatomical detail:variable
Abundance in sediment:abundant
Collection methods and comments
Reason for describing collection:taxonomic analysis
Collectors:E. C. Olson Collection dates:1949
Metadata
Database number:177006
Authorizer:R. Butler Enterer:E. Dunne
Research group:vertebrate
Created:2016-03-15 12:15:56 Last modified:2016-03-15 12:15:56
Access level:the public Released:2016-03-15 12:15:56
Creative Commons license:CC BY
Reference information

Primary reference:
58444. E. C. Olson. 1958. Fauna of the Vale and Choza: Summary, Review, and Integration of the Geology and the Faunas. Fieldiana Geology 10(32):397-448 [R. Butler/E. Dunne]