Linoproductus sp. brachiopod from Texas

These next two, giant brachiopod shells are Linoproductus sp. from the early Permian aged (Asselian stage to Sakmarian stage of the ICS, Wolfcampian stage in US stratigraphy) sediments of Callahan County, Texas. This genus is known for having some of the largest shells for brachiopods from the period. The pedicle valve is very convex and the brachial valve startes our flat but becomes concave as the animal got older. The margins of the two valves are often turned 90 degrees from the hinge and (at least in the two specimens I am blogging about today) become very elongated. The surface of  both valves are marked with fine striations that are slightly wavy. Occasional spines are present but appear to not be in any planned arrangement.

Specimen #1 - Pedicle valve (note the grooves and marks in the shell which may be indicative of a boring sponge called Clionolithes sp.)

Anterior

Brachial valve and shell margins

Posterior

Profile

Another view of the brachial valve and the shell pattern

Specimen #2 - Pedicle valve

Anterior

Brachial valve

Posterior

Profile

These specimens come from rocks near Putnam, Texas in Callahan County.