Stromboidea
Original Description of Anchura (Drepanochilus) perveta by Stanton, 1920, p. 38:
- "Shell of medium size, fusiform, consisting of eight or more whorls; spire considerably shorter than combined length of aperture and canal, with strongly rounded whorls tending to become subcarinate; last whorl with three conspicuous carinae, of which the uppermost is largest and extends to the upturned pointed end of the winglike outer lip, and the lowest one is smallest; anterior canal short, narrow, and straight; lower and outer margin of the expanded outer lip forming a broad sigmoid curve, upper margin strongly concave, with varying curvature in different individuals, and extended upward on the spire to the antepenultimate whorl; no posterior canal; inner lip connected above with the outer lip and thickened by a heavy callus, which is especially prominent over the middle and lower carinae, beneath which it is suddenly contracted; outer lip also greatly thickened by an internal deposit on mature specimens; surface of the spire marked by strong oblique or slightly curved ribs crossed by fine, inconspicuous, closely arranged spiral lines, there being about 15 or 16 ribs and 30 or more lines on each larger whorl of the spire. On the last two whorls the ribs are gradually shortened until on the back of the last whorl they are reduced to strong tubercles on the upper carina and cease entirely before the carina reaches the wing."
Stratum typicum: Danian (?), Paleocene, Paleogene (Cvancara, 1976)
Anchura (Drepanochilus) perveta Stanton, 1920, pl. 7, fig. 1a,b , 2a,b ,3a,b
Anchura (Drepanochilus) perveta var. gracilis Stanton, 1920, pl. 7, fig. 4
References
- Cvancara, A.M., 1976. Geology of the Cannonball Formation (Paleocene) in the Williston Basin, with reference to Uranium potential; Report of Investigation no. 57, North Dakota Geological Survey, Fulltext
- Stanton, 1920
