"Chlamys" cawcawensis (Harris, 1919)
HARRIS, G. D. 1919. Pelecypoda of the St. Maurice and Claiborne Stages. Bulletins of American Paleontology, 6 (31): 5-268, pls. 1-59. [p. 27, pl. 15 (not 16 as in text), figs. 1-7]
1919 Pecten cawcawensis Harris, 1919
G. D. Harris, 1919, plate 15.
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«Specific characterization.— Size and outline as indicated by the figures; surface ornamentation, —about 23 ribs on each valve, broad with narrow interspaces on the right, narrower with wider interspaces on the left; rarely signs of intercostae on the right, conuuon on the left; imbricating, fine, concentric, lamellse more pronounced on the right valve.
This form has usually passed under the name of deshayesi, but it will be seen by examining pls. 14 and 15 that the ribs of cawcawensis are much more sharply defined and differentiated and lack the excessive ornamentation of superimposed riblets with scaly imbrications in high relief. However, both are of the same stock and doubtless will seem to intergrade when enough material is collected from a large number of Mid-Eocene localities. Types.— Paleont. Mus., Cornell Univ. Horizon.— St. Maurice Eocene. Localities.— Columbia Road, 17 mls N. of Orangeburg, S. C. (not far from Cawcaw Swamp) ; Claiborne, Ala? (see pl. 13, fig. 8). Above Newbern, Neuse River, N. C. Specimens from a locality numbered 5,205 in the U. S. Nat. Mus. Catalogue (Flint River, old Danville Ferry, 16½ mls E. of Americus, Ga.) labelled deshayesi are more probably varieties of cawcawensis.» GILBERT DENNISON HARRIS, 1919
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«Discussion: Baum et al. ( 1979, p. 89) listed Chlamys cawcawensis among "the faunal elements which have generated the greatest confusion" in the Eocene of the Carolinas. Harris (1919) obtained the syntypes of C. cawcawensis from the "McBean Formation" (probably not the silicified Orangeburg District Beds of Dockery and Nystrom, 1992a). However these specimens are poorly preserved. Harris also figured a complete specimen from Alabama (1919, pl. 13, fig. 8) and suggested that it might be a variety of C. cawcawensis. Many later authors have used this specimen in their species concept (e.g., Toulmin, 1977, whose specimens from the Moodys Branch Formation closely resemble this one). The Alabama specimen is not conspecific with the syntypes, having smooth, uniform primary ribs, whereas true C. cawcawensis has fine concentric sculpture on the primary ribs, which bifurcate irregularly.
The name has been widely misapplied to a younger species common at GP [Giant Portland cement quarry], as discussed below. Both species have narrow interspaces, although those of true Chlamys cawcawensis are wider than those of the undescribed species. My specimens of this taxon are from SAO [Southern Aggregate Orangeburg quarry], MMB [Martin Marietta Berkeley quarry], and a locality with silicified shell north of Orangeburg, S.C.» CAMPBELL, D. C. 1995. New molluscan faunas from the Eocene of South Carolina. Tulane Studies in Geology and Paleontology, 27: 119-152, pls. 1-9. [p. 125]
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Chlamys cawcawensis; D. C. Campbell, 1995, New molluscan faunas from the Eocene of South Carolina, plate 1, figure 1.
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