Turritella alumensis

Geological Range

Late Pliocene; Extinct.

Paleogeographic Distribution

Southern Florida to Virginia.

Remarks

Original Description (from Mansfield, 1930, p. 105):

"Shell large, solid, moderately stout, probably of about 25 whorls on complete specimens. Suture impressed. Whorls nearly flat, medially depressed between primary spirals, upper whorls more so than later. Apical whorl rather large, flatly coiled, tip shallowly immersed. Spiral sculpture, on the earliest whorls, of a sharp basal keel. On ascending the whorl, another spiral begins below the suture, weak at first but later nearly equals in strength the basal one. Sculpture on later whorls of 3 primary spirals, one at the upper fourth and two at the anterior fourth and base. The basal spiral is weakest, the other two being of about equal strength. Aside from the primaries, flat secondary threads, usually intercalated by threadlets, overrun the surface.

Larger cotype with earlier whorls missing (U. S. Nat. Mus. Cat. No. 370319) measures: Altitude, 115 mm.; greatest diameter, 24 mm.

Occurrence: Upper Miocene: Upper bed at Alum Bluff, Liberty County, type locality (abundant); station 1/962, near Watsons Landing, Liberty County (rare?); station 1/960, Darlings Slide, Calhoun County (rare); station 3423, lower upper Miocene bed at Jackson Bluff, Leon County (common).

Turritella aguilerae Bose from near Tuxtepec, Mexico, is closely related to T. alumensis.

Specimens collected from the lower bed at Rushmere Wharf, James River, Va., are also nearly related to the Alum Bluff species."

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Stratigraphic Occurrences

Late Pliocene

Duplin Formation (SC)

Jackson Bluff Formation (N. FL)

Tamiami Formation (Pinecrest Beds) (S. FL)

Yorktown Formation (VA)

Yorktown Formation (Lower) (VA)