Species / Ceratosiphon Densestriatus
Stromboidea
Diagnosis of Ceratosiphon densestriatus by Kase, 1980, p. 314:
- "A large sized species of Ceratosiphon characterized by a proportionally higher spire, prominently biangulated body whorl and impressed suture. Posterior spine extended slightly beyond spire. Anterior siphonal canal thin with a thin spine branching from posterior part at nearly a right angle. Surface sculptured by numerous very fine spiral threads."
Original Description of Ceratosiphon densestriatus by Kase, 1980, p. 314:
- "Shell large but thin-shelled with more or less abruptly tapered spire. Incremental angle in neighbourhood of body and penultimate whorls about 40° but apical angle about 90°. Volutions seven or eight in number. Protoconch of three smooth and well rounded naticiform whorls, followed by a fourth well rounded whorl bearing cancellated ornamentation consisting of six distinct and regularly spaced fine spiral cords and similarly strengthened opisthocyrt axial threads. Spire whorls regularly expanded, separated by impressed suture. Whorls abruptly changing from protoconch without distinct boundary. Second and third teleoconch whorls prominently angulated at middle with broad ramps and nearly vertical whorl sides. Surface sculpture of second teleoconch whorl consisting of three spiral cords on ramp and nine finer ones on the whorl side. Third teleoconch whorl with much finer and numerous spiral cords or threads. Axial sculpture of these whorls much finer than of the first teleoconch whorl. Body whorl prominently biangulated at periphery, convex and anteriorly constricted, and ornamented by much finer and numerous spiral threads. Aperture wide and semilunar in outline. Outer lip with three extended outer spines. Posterior spine thick, adnate to the spire and more or less extended posteriorly beyond spire; two other spines extended from two ridges of body whorl and moderately long for this group. Anterior siphonal canal thin and slightly curved with a thin spine branching from posterior part at nearly right angle. Inner lip long and nearly straight with a thin callus that extends onto body whorl."
Locus typicus: northern coast of Kimigahama, Ashikajima-cho, Choshi City (35°42´54´´N, 140°52´24´´E), Japan
Stratum typicum: 50 m above the base of the Kimigahama Formation, Barremian, Cretaceous
Ceratosiphon densestriatus Kase, 1980, Paratype; Coll. NSM PM15057, photo Takuma Haga
References
- Kase, T. & Maeda,H. 1980. Early Cretaceous Gastropoda from the Choshi District, Chiba Prefecture, Central Japan; Transactions and proceedings of the Paleontological Society of Japan. New series 1980(118), 291-324, (Internet)->http://ci.nii.ac.jp/naid/110002703111]].
