Subclass Amphigastropoda Simroth, 1906
Order Bellerophontida McCoy, 1852
Subfamily Euphemitidae Knight, 1956
Genus Euphemites Warthin, 1930

Euphemites are distinct, with their coarse spiral ornamentation visible on the outer shell. Moore (1941) well-illustrated the internal shell structure of Euphemites in a series of figures (see Moore 1941, figs. 1–4) as part of a study on Pennsylvanian gastropods from Kansas. One non-obvious feature to a casual observer of these fossilized shells is that the spiral ornament on the surface instead forms on the inductra, the inside shell layer in the aperture. There are various theories on how this occurs, but not one is accepted. No living Bellerophonts exist today.

This genus is ubiquitous in the shale at the Pine Creek limestone locality. Unfortunately, most specimens from the Pine Creek limestone are tiny. I have only recovered one example from the Brush Creek limestone in Parks Township; it has an enormous and thick shell.

Fig. 1—Euphemites sp. from the Pine Creek limestone at SL 6445 A–C, a broken specimen in three views, CG-0575. A, broken apertural view with freshly exposed spiral ornament, B, abapertural view, with weathered spiral ornament C, original unbroken apertural view of the specimen with an extra half volution and smooth surface. Scale bar = 5 mm.

Genus Euphemites Warthin, 1930
Species nodocarinatus (Hall, 1858)

The gastropod Bellerophon nodocarinatus (=Euphemites nodocarinatus) was named by Hall in 1858 in a geological report of Iowa. The name means knotty/lumpy kneels (or carina), characterized by the dual lumpy ridges visible from the anterior margin across the shell. Members of Euphemites have spiral lirae that appear in the aperture and extend toward the anterior margin. The whorl width expands as the shell enlarges. Research of the shell layers (Moore, 1941) has shown that the creature added the spiral lirae to the shell after primary growth, likely with modification of the original nodose carina feature.

Hall was reporting on fossils from upper and lower coal measures without distinction. He noted that the reported fossils are common in Western Pennsylvania and elsewhere.

Fig. 2—Euphemites nodocarinatus from the Brush Creek limestone at SL 6533. A–D, four views of CG-0611. A, abapertural view with the two nodose carina visible; B, side view with visible spiral lirae; C, “nose” view ; D, apertural view. Scale bar = 5 mm.

References