Argopecten vicenarius charlottensis (Mansfield, 1936)
MANSFIELD, W. C. 1936. Stratigraphic significance of Miocene, Pliocene and Pleistocene Pectinidae in the Southeastern United States. Journal of Paleontology, 10 (3): 168-192, pls. 22-23. [p. 189, pl. 23, figs. 8-9]
1936 Pecten (Chlamys) evergladensis charlottensis Mansfield, 1936
W. C. Mansfield, 1936, plate 23.
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«Shell of medium size; left valve more strongly convex than right, both valves inequilateral, the posterior region being more produced. Anterior ears slightly larger than posterior; right anterior ear weakely sinuate, sculptured with 5 radials crossed by closely spaced lamellae; right posterior ear sculptured with 8 radials crossed by closely spaced lamellae. Submargins steep, sculptured only with fine, crowded lamellae. Ribs 21 in number, rather high, nearly flat topped, weakely undercut on the sides. Interspaces on the right valve slightly narrower than the ribs; on the let valve about equal in width.
Dimensions of syntypes (U. S. Nat. Mus. 154183): Right valve, length, 70 mm.; height, 63 mm.; convexity, 16.5 mm. Left valve, length, 72.5 mm.; height, 64 mm.; convexity, 19.5 mm. The new subspecies differs from Pecten evergladensis Mansfield in having squarer ribs, more closely spaced concentric lamellae and a relatively narrower shell; and from Pecten gibbus irradians Lamarck, a Recent species of Florida, in having a more inequilateral shell, smooth instead of radially striated submargings, a lower right valve and a slightly higher left valve. P. (C.) circularis Sowerby, a Recent species that ranges along the Pacific coast from Monterey, California, to Paita, Peru, is very closely related to the new subspecies, differing mainly in having wider and less squarely cut ribs. Type locality: Shell Creek, Charlote County, Florida, Joseph Wilcox, collector. Occurrence: Pliocene Caloosahatchee marl: Shell Creek (common); Caloosahatchee River (rare); Alligator Creek (?), small specimen.» WENDELL CLAY MANSFIELD, 1936
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«Comparison. A. vicenarius charlottensis differs from A. vicenarius vicenarius in having thicker valves with higher, more angular plicae and disk flanks that are steeper and less commonly costate. Compared to the Miocene A. comparilis (high-ribbed ecotype), the Pliocene form has a left-convex, rather than slightly right-convex, shell of greater thickness and larger size.
Stratigraphic range, geographic distribution, and ecology. The subspecies is thus far known only from the Pliocene Caloosahatchee Marl at a few localities in southwestern Florida. Because all of the specimens on hand were collected from float adjacent to the Caloosahatchee Marl, little can be said about the paleoecology of the subspecies on the basis of associated fauna or sediments. By analogy with the species pattern of living scallops, however, A. vicenarius charlottensis, like the northern subspecies, A. vicenarius vicenarius, is inferred to have lived in the open waters of the upper continental shelf, because presumably it lived simultaneously with A. anteamplicostatus and because the morphological differences between these two species are analogous to those that separate living calico and bay scallops.» WALLER, T. R. 1969. The evolution of Argopecten gibbus stock (Mollusca: Bivalvia), with emphasis on the Tertiary and Quaternary species of Eastern North America. The Paleontological Society. Memoir 3 [Journal of Paleontology, 43 (5, supplement)]: 125 pp. [p. 50, 51]
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Argopecten vicenarius charlottensis (Mansfield); T. R. Waller, 1969, The evolution of Argopecten gibbus stock, plate 7, figures 1-6.
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