Stromboidea

• Rostellariidae
  • Calyptraphorus
    • Calyptraphorus sp.

Calyptraphorus sp.; mid-Pliocene Tartaro Formation in the Angat area, Bulacan Province of northern Luzon Island, Philippines; Coll. NMNS no. PM25619; Copyright T. Kase

Description of Calyptraphorus sp. by Kase & Aguilar, 2014:

• "Shell fusiform, completely covered with thin glazed callus, consisting of ca. 13 whorls including protoconch. Protoconch naticiform, smooth, but details of coiling pattern and sculpture unknown. Teleoconch comprising ca. 10 weakly convex whorls separated by a very weakly impressed suture. Surface sculpture of whorls obscurely observable under callus cover, consisting of orthocline axial ribs and numerous fine spiral cords; number of axial ribs uncountable, but four ribs observed beneath callus on one-fourth of eighth whorl; axial ribs becoming obsolete on penultimate whorl, absent from last whorl. Blunt varices seemingly present at irregular intervals on some whorls, recognized as a swelling of callus. Last whorl occupying more than half of total shell length, strongly tapered anteriorly, incomplete, seemingly with a short, narrow anterior canal. Outer lip totally missing. Posterior canal extending posteriorly up to base of seventh whorl, then U-turned, extending anteriorly to posterior part of last whorl."

Locus typicus: AGT 2 (14°57.114'N, 121°02.999'E), riverbed of the Bayabas River in the barangay (village) of Banaban, Angat Municipality, Bulacan Province, Luzon Island, Philippines.

Stratum typicum: lower part of the Tartaro Formation, Pliocene

Calyptraphorus sp., see O'Leary et al., 2019, p. 81

Calyptraphorus Conrad, 1858 (“1857”)

• ? Calyptraphorus sp.
• Figure 39D-F
• Horizon in Study Area and Age: Menaka Formation of the Iullemmeden Basin. Maastrichtian.
• Locality: Mali-1.
• Depositional Environment: Interbedded shale and marl (Facies 4); shallow, sublittoral open marine settings with water depths <50 m.
• Referred Material: CNRST-SUNY 177a.
• Description: Cast with fusiform outline and polished surface due to callus cover.
• Discussion: Specimens are similar to the Paleocene Rimella ewekoroensis of Nigeria (Adegoke, 1977), which is not Rimella but likely Calyptraphorus (Squires, 2013).

References

• Kase, T., Aguilar, Y.M. 2014. The gastropod genus Calyptraphorus (Rostellariidae: Stromboidea: Mollusca): A lazarus taxon from the Pliocene of the Philippines; Paleontological Research, 18 (3) pp. 169-175.
• O'Leary, M.A., Bouré, M.L., Claeson, K.M., Heilbronn, K., Hill, R.V., McCartney, J., Sessa, J.A., Sissoko, F., Tapanila, L., Wheeler, E. & Roberts, E.M. 2019. Stratigraphy and Paleobiology of the Upper Cretaceous-Lower Paleogene Sediments from the trans-Saharan Seaway in Mali; Bulletin of the American Museum of Natural History 436, 177 pp., Fulltext