Map point data provided by iDigBio.
- C5 Sequence (Waynesville)
Identification in Hand Sample
Cymatonota typicalis from Clarksville, Ohio (CMC 61617)
- Pelecypod. Internal mold. Note straight hinge-line and lack of muscle impressions. Shell very thin, rarely seen. Waynesville.
- Shell elongate, with the dorsal and ventral margins parallel, the length three and one-half times the height, the greatest thickness, which is a little behind the center, about two-thirds of the height; anterior end nearly vertical, rounded but not uniformly, the turn into the hinge line being rather abrupt; posterior margin rounded, slightly oblique, most prominent in the lower half; ventral margin gently concave. Beaks appressed, scarcely prominent, situated one-fifth of the length of the shell behind the anterior extremity; umbonal ridge and mesial sulcus rather distinct features, cardinal region anterior to the beaks sharply compressed. Surface with fine equal striae anterior to the beaks, of which not over half continue over the flanks of the shell where they take on an irregular character, some being much stronger than the others; or several may be united into a fold. The umbonal ridge is almost smooth, but the upper part of the posterior cardinal slope is marked with rather regular, strong, oblique folds.
- Formation and Locality: Upper beds of the Cincinnati group, Waynesville, Ohio.