Species: Clathrospira conica (Ulrich & Scofield, 1897)
Map point data provided by iDigBio.
- C2 Sequence (Fairmount)
Identification in Hand Sample
- Stretched appearance
- The whorl surface between the sutures is large and concave.
- Angulation on the whorl below the selenizone.
Clathrospira conica from Marble Hill Bed formation of Pendleton County, Kentucky (OUIP 1778)
Ebbestad & Peel (2001):
- The type species, Clathrospira subconica (Hall, 1847) as illustrated by Knight(1941) is distinguished by its inflated base, cancellate ornamentation without nodes or rugation, and the presence of a short slit that generates a broad selenizone bounded by spiral cords.
- Gastropod. Internal mold, showing unornamented volutions and a moderately high spire. Shell itself is subconical, with sharply angulated whorls. Fairmount.
- Clathrospira conica has an angulation on the whorl below the selenizone and a concave whorl surface between sutures.
Ulrich & Scofield (1897):
- This species has been, we believe, often confused with young specimens of C. subconica Hall sp. Though greatly resembling that species, especially in the condition of casts, and perhaps derived from it, it is nevertheless a well-marked form and worthy of a distinct name. It is always smaller, the largest of over fifty specimens being only 25 mm. wide, while in at least four-fifths of the specimens found in the Black River and Trenton groups the width is less than 18 mm. The average width of the Cincinnati form is somewhat greater, being something like 23 or 24 mm. Aside from the matter of size, the species differ constantly from C. subconica in at least two particulars. First, the upper slope of the whorls is nowhere convex but is either gently concave throughout or flat from the linear suture to the rising base of the upper boundary of the peripheral band. The second difference lies in a more or less well-marked concave space which occupies the outer third of the base of the whorls. The inner border of this space is often very sharply defined on testiferous examples and readily traced on most casts of the interior. Among less obvious and perhaps less constant differences we may mention that the periphery is more angular, the whole base less convex, and the surface markings altogether less beautiful, less distinct and less regular. In C. subconica the lines of the surface sculpture are sharply raised and look like woven threads; in C. conica they are neither sharp nor thread-like and generally require a good glass to bring them out at all.