Original description of Ceratosiphon giganteus by Kase, 1984
- "Shell large with rather abruptly tapering spire. Incremental angle of body and penultimate whorls about 35 degrees. Protoconch missing. Whorls at least six in number. Suture impressed. Spire whorls sharply angulated at middle with steeply inclined ramp and almost vertical whorl sides. Body whorl convex, bicarinate and anteriorly constricted. Outer lip with three extended spikes; upper spike adnate to spire and extended posteriorly beyond spire, and two other spikes poorly known. Anterior siphonal canal thin and long with a spine branching from its upper part. Surface sculptured by very fine spiral cords."
Locus typicus: Massaki in the Ofunato- Omine-mine area, Kinchakuiwa, Japan
Stratum typicum: Hijochi Formation, early Barremian, lower Cretaceous