Trachydomia nodosa (Meek & Worthen, 1861)
Showy gastropod with prominent nodes
Middle Pennsylvanian Series - Desmoinesian Stage
Marmaton Group - Altamont Formation
Lake Neosho Shale Member - St. Louis, Missouri
The abundance is considered common, however, large adult
specimens are rarely found.
This species is illustrated in Knight (1933) and is listed in Yochelson
(1967). There is a partly developed shoulder on the upper part of
the whorl that does not have nodes on th