Original Description of Calyptraphorus carrizensis by Gardner, 1945, p. 167:
- "Shell small, slender. Whorls of the conch probably about 7, those of the protoconch 4. Initial turn minute, the 3 succeding nuclear whorls rapidly enlarging, broadly rounded and separated by incised suture lines. Sculpture initiated on earlist postnuclear whorl. Adolescent sculpture of narrow, feebly arcuate, protractive riblets averaging about 14 to the whorl and crossed by about 7 feeble, flattened, spiral threads; axial sculpture evanescent on the next to the final whorl, the spiral sculpture increasingly feeble. Adult veil produced backward. Apertural face in the type flattened; an obscure callus fold on either side and a prominent node midway between them at the rear of the shell. Anterior extremity not preserved in any specimen. Outer lip much thickened and produced backward; the callus covering a large spatulate area on the back of the 3 or 4 later whorls. Callus margins thickened and separated only by a deep groove extending in the adult from the posterior angel of the aperture (in the specimen figured) to the suture line between the third and fourth whorls; callus following the suture for a fraction of a whorl, then curving forward to the body. Body rounded and obliquely constricted to the slender pillar."
Stratum typicum: Carrizo Sandstone, Eocene
Locus typicus: Alamo River, Tamaulipas & Nuevo Leon States, Mexico
- Gardner, J.A. 1945. Mollusca of the Tertiary Formations of Northeastern Mexico; Geol. Soc. Amer., Memoir 11, 332 p., 27 pls, Fulltext