ammonites
Pseudozygopleura werneri Knight 1930

Full reference: J. B. Knight. 1930. The gastropods of the St. Louis, Missouri, Pennsylvanian outlier: the Pseudozygopleurinae. Journal of Paleontology Memoir 4(4):1-88

Sister taxa: none

Type specimen: YPM 12962, a shell. Its type locality is SL-1. Headwaters of Feefee Creek, north of Olive St. & west of Lindberg Blvd., 1.5 km northwest of Stratmann (Olivette), which is in a Moscovian marine shale in the Appanoose Formation of Missouri.

Average measurements (in mm): shell 12.0 x 2.8