Stromboidea
Original Description of Rostellaria biangulata by Meek & Hayden, 1856, p. 65:
- "Shell elongated; spire elevated, acutely conical; volutions seven or eight, convex, crossed by small nearly obsolete folds, last one having two distinct revolving carinae on the middle, which diverge in passing upon the expanded lip, and terminate in two more or less salient angles at its outer margin; surface marked by fine very faint lines of growth, crossed by small revolving thread-like lines about equal the intermediate spaces, on the spire and upper part of the last turn, but more distinct and alternating with smaller ones on the lower part of the body volution; suture linear, sharply impressed; aperture unknown; outer lip thin, expanded, and extending more or less up the spire. Length .53 inch, breadth exclusive of the lip .21 inch; apical angle regular, divergence 37°."
Locus typicus: Yellowstone River, 150 miles from its mouth, Glendive, Dawson County, Montana, USA
Stratum typicum: Baculites baculus zone, Pierre Shale, Maastrichtian, upper Cretaceous
History and Synonymy
1856
Rostellaria biangulata Meek and Hayden, Acad. Nat. Sci. Philadelphia Proc., v. 8, p. 65
1860
Aporrhais biangulata Meek and Hayden, Acad. Nat. Sci. Philadelphia Proc., v. 12 p. 186
1876
Aporrhais biangulata in Meek, 1876, p. 322, fig. 37
- Comment Meek, 1876, p. 322: "A magnified outline from a specimen showing that it has the usual posterior canal ascending the spire"
Aporrhais biangulata in Meek, 1876, pl. 19, fig. 6 a, b, c
Aporrhais biangulata Meek and Hayden. Meek, U.S. Geol. Survey Terr. (Hayden) Rept. v. 9, p. 322, pl. 19, figs. 6A, b, c, fig .37.
1904
Chenopus (Chenopus) biangulata (Meek and Hayden). Cossmann, Essais de paleoconchologie comparee, v. 6, p. 55
1917
Aporrhais biangulata (Meek and Hayden). Dowling, Canada Geol. Survey Mem. 93, p. 46, pl. 29, figs. 6, 6a.
1967
Aporrhais biangulata Meek and Hayden. Sohl, 1967
Description of Aporrhais biangulata by Sohl, 1967, p. B20:
- "Description. - Medium-sized turriculate shells, spire slightly more than one-half total height. Pleural angle 28°-31°. Protoconch unknown, teleoconch whorls about seven in number, broadly rounded on sides with greatest curvature at about two-thirds to three-fourths below suture; a peripheral carination develops at this position, usually on the penultimate whorl. Body whorl bicarinate with upper carination strongest, whorl profile convex suture to carination, concave between carinations, steeply sloping and broadly concave below. Sculpture dominantly spiral consisting of numerous crowded spiral threads of variable strength that cover the whorl surface. Transverse sculpture of generally weak highly arcuate collabral ribs. Ribs restricted normally to medial half of whorl accentuated at periphery to subnodings. Aperture lanceolate, anteriorly extended to an elongate shallow canallike groove of the curved pillar, inner lip with moderately thick callus that is posteriorly, laterally, and anteriorly continuous with the expanded outer lip. Outer lip expanded to a broad flaring wing that extends upward adnate to the spire for nearly its full length. This flange is not grooved interiorly, lies at an angle to the lateral extensions, and is partly separated by a sulcus; lateral wing extension grooved interiorly in harmony with the lateral extension of the carinations of the body whorl, which terminate in blunted spikes separated by a broad shallow sulcus; posterior slope of wing broadly concave to the elongate curved anterior spike. Growth line strongly arcuate, opisthoclinely opisthocyrt."
Aporrhais biangulata in Sohl, 1967, pl. 2, fig. 10
- Dorsal view of a specimen from the Pierre Shale (Baculites baculus zone) of the Cedar Creek anticline, Montana, USA; Coll. USNM no. 132698
- Image courtesy of the USGS
Aporrhais biangulata in Sohl, 1967, pl. 2, fig. 11
- Dorsal view of a specimen from the Pierre Shale (Baculites baculus zone) near Glendive, Dawson County, Montana, USA; Coll. USNM no. 132965
- Image courtesy of the USGS
Aporrhais biangulata in Sohl, 1967, pl. 2, fig. 16
- Ventral view of the paratype from the Pierre Shale (Baculites baculus zone) near Glendive, Dawson County, Montana, USA; Coll. USNM no. 132967
- Image courtesy of the USGS
1979
Aporrhais biangulata kamchatica Blank, 1979
References
- Dowling, D B, 1917. Southern plains of Alberta. Geological Survey of Canada, Memoir no. 93, Ottawa, Government Printing Bureau, 1917, 1 p. l., ii, 200, viii p. incl. illus., XXV pl.
- Meek, F.B. & Hayden, F.V. (1856). Descriptions of new species of Gasteropoda from the Cretaceous formations of Nebraska Territory. Proceedings of the Academy of Natural Sciences of Philadelphia. 8, 63-69.
- Sohl, 1967
