Stromboidea
Original Description of Anchura abrupta by Conrad, 1860, p. 284:
- "Body whirl with a broad revolving rib on a line with the upper extremity of the aperture, with an impressed line on the middle dividing it into two equal parts; about fourteen revolving tuberculated unequal ribs; labrum produced, thick, birostrate, outer margin straight; columella deposit broad and thick; the posterior margin abrupt, subcarinated; beak elongated, curved, spiniform; submargin of the outer extremity of labrum acutely carinated within."
Locus typicus: Tippah County, Mississippi, USA
Stratum typicum: "The type horizon of the type species A. abrupta is probably the Coon Creek Tongue of the Ripley Formation in either Tippah or Union County, Mississippi." (Dockery, 1993)
Anchura abrupta Conrad, 1860, pl. 47, fig. 1
History and Synonymy
Anchura abrupta Conrad, 1 860: 284, pl. 47, fig. 1.
- Rostellaria hebe Whitfield, 1892: 111.
- Drepanochilus? martini Stephenson, 1941: 306.
1868
Anchura abrupta in Gabb, 1868, pl. 14, fig. 13
1907
Description of Anchura abrupra Conrad, 1860 in Weller, 1907:
- "Shell with a rather high spire having an apical angle of about 30°, and a comparatively short body volution, with a slender rostrate, anterior canal; the dimensions of a moderately large internal cast retaining a little more than three volutions, and incomplete at both the apex and the anterior extremity, are: length, 51 mm.; greatest diameter, 30 mm.; height of aperture, 21.5 mm.; width of aperture, 10.5 mm. If this specimen were complete it would have an additional height at the apex of about 20 mm., and an anterior beak about 30 mm. in length. The outer lip of the aperture is produced and terminates in two unequal pointed processes one directed forward and the other backward. Surface of the shell marked by a rather strong, nodose, subangular, revolving keel at a little above the mid-height of the outer volution. Upon the expanded portion of the outer lip this keel curves upward to the posterior process of the lip. Above and below the median keel the surface is marked by moderately broad, rather depressed revolving ribs, and by less conspicuous vertical markings. On the internal casts, in which condition only the species has been seen in New Jersey, the surface is marked in the younger individuals by more or less indistinct revolving and vertical ribs, which evidently were obliterated by the internal thickening of the shell, since the larger individuals are all smooth. The aperture in the casts is narrowly sub elliptical in outline, the outer side being a little more strongly curved than the inner. The columellar cavity left in the casts is rather broad and is not marked by revolving folds."
Localities: Crawfords Corner and Mullica Hill, New Jersey, USA
Stratigraphy: Navesink Formation (Navesink marl), Maastrichtian, upper Cretaceous
Anchura abrupta in Weller, 1907, pl. LXXXII, fig 1 - 6 and pl. LXXXIII, fig 3, 4
Comment of Weller, 1907:
- "In New Jersey this species is known only in the condition of internal casts, which are all imperfect, the apex of the spire and the anterior rostral extension and the outer lip of the aperture being lacking in every example observed."
1941
Drepanochilus ? martini in Stephenson, 1941, pl. 57, fig. 5
1960
Anchura abrupta in Sohl, 1960, pl. 12, fig 1, 4-9 and 12
- Ripley Formation, Maastrichtian, Cretaceous
- image courtesy of the U.S. Geological Survey
1993
Anchura abrupta Conrad, 1860 in Dockery, 1993, pl. 15, figs. 1-3
- image courtesy of the Mississippi Geological Survey
Specimens from institutional collections
Anchura abrupta Conrad, 1860; Prairie Bluff Chalk, Selma Group, Maastrichtian, Cretaceous; Alabama or Mississippi, USA; Coll. Yale Peabody Museum of Natural History YPM IP 325143
References:
