First described by Norwood and Pratten in 1855, Shansiella carbonaria is a very common fossil gastropod. The species existed from 306.95 until 295 million years ago. The genus Shansiella, first described by Yin in 1932, existed from 360.7 until 254 million years ago. The genus described after the species is confusing. However, the species was originally named Pleurotomaria carbonaria. Later it moved to the newer genus Shansiella in 1932.
Specimen CG-0060 – This specimen is from the Ford City Pine Creek Limestone. These weather out with beautiful shell patterns visible at that location. The shale/limestone layer they are embedded in is very fissile. Splitting this limestone is very easy. In comparison to the more cement like Brush Creek limestone, this is an easy matrix to work.
In the photo above, the growth lines are visible on the right side. The aperture, or shell opening, is to the left.
A second specimen
Specimen CG-0061 – This is a larger example found at the same time as CG-0060. It was much larger and still attached to limestone, but not attached to the hillside, rather lying in the talus pile. It had a natural cleaved plane, from it’s fossilized position it the rock. I took my polishing tool and used it to smooth out the surface to show additional details. The shell thickness, ornamentation and even a small spot of pyrite are visible on the polished side. While the shell surface appears lumpy, you can see the fine spiral pattern locked in limestone. The shell material fell off the top spiral, exposing the calcite steinkern.
Shansiella carbonaria on the web
- Pine Creek Gastropods – From an earlier trip