Original Description of Calyptraphorus binodiferus by Perrilliat & Vega, 1997:
- "Shell medium-sized. Protoconch with three, rounded smooth whorls; teleoconch with seven rounded whorls. Sculpture of shell consisting of numerous axial ribs; first whorl with 30 axial, rounded, prosocline ribs; interspaces as wide as ribs. On next whorls ribs lessen, on one whorl 14, on the next 12, with interspaces wider than ribs. On last whorl ribs disappearing, with shell practically smooth. Weak spiral ribs present on spire, being more pronounced near suture. Suture impressed. Aperture not preserved in any specimen. Callus covering entire surface of shell. Canal extending upward, forming a curved channel through the callus, not covering first three whorls of spire; then curving downward. Callus irregularly thickened on either side of groove. The most distinctive feature of the species being the presence of two nodes on the body whorl, one near aperture and another near the canal. No sculpture on the side of body whorl opposite the nodes, with exception of spiral striae near suture."
Locus typicus: Texmalac, Guerrero State, Mexico
Stratum typicum: Mexcala Formation, lower Maastrichtian, upper Cretaceous