Eburneopecten scintillatus (Conrad, 1865)
CONRAD, T. A. 1865. Descriptions of new Eocene shells from Enterprise, Mississippi. American Journal of Conchology, 1: 137-141, pls. 10, 11. [p. 140, pl. 10, fig. 4]
1865 Pecten (Eburneopecten) scintillatus Conrad, 1865
1866 Camptonectes claibornensis Conrad, 1866 [nomen nudum]
1866 Camptonectes claibornensis Conrad, 1866 [nomen nudum]
«In the present study, the tribe Eburneopectinini is limited to the genus Eburneopecten because of morphological and stratigraphic evidence that this genus evolved from coarsely ribbed Dhondtichlamys in the early to mid-Eocene of eastern North America and is phylogenetically independent of so-called "Eburneopecten" in Europe (Fig. 1.2, Node E1 compared to A6). Well-preserved specimens of E. scintillatus consistently display fine radial costellae on the left beak that are ontogenetically decoupled from later costae that may appear near the ventral margin. The species retains costae throughout ontogeny on its right anterior auricle, whereas the costae on other auricles are absent or limited to early ontogeny. Similar decoupling of ribbing occurs within the range of variation of two older species that resemble E. scintillatus, and they are included here in Eburneopecten. One of these is E. clarkeanus (Aldrich, 1895) from the Cook Mountain Formation of Alabama of Bartonian age; the other is E. burlesonensis (Harris, 1919) from the Weches Formation of Texas of middle Lutetian age. The latter, older species resembles Dhondtichlamys in having strong steep-sided plicae but differs in having much finer antimarginal microsculpture in the rib interspaces. Both of these species exhibit great variation in the degree of rib interruption, with some specimens approaching the nearly smooth condition of Eburneopecten scintillatus. (See illustrations of these species in Harris 1919, pI. 14, figs. 11-13 and pI. 15, figs. 8-13.)»
WALLER, T. R. 2006a. New Phylogenies of the Pectinidae (Mollusca: Bivalvia): reconciling Morphological and Molecular Approaches. In S.E. Shumway & G.J. Parsons (Ed.) 2006: Scallops: Biology, Ecology and Aquaculture, 1-44. [p. 14, 15]
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Figure 1.2. A phylogeny of the six tribes of the subfamily Palliolinae.
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«Pecten (Pseudamusium) scintillatus Conrad
Pecten (Eburneopecten) scintillatus Conrad, Am. Jour. Conchology, vol. 1, p. 140, pI. 10, fig. 4, 1865 (young shell).
Camptonectes scintillatus Conrad, Checklist of the invertebrate fossils of North America, Eocene, p. 23, 1866. Camptonectes claibornensis Conrad, op., cit. (1866), p. 23 (name only) . Pecten claibornensis Harris, Arkansas Geol. Survey Rept. for 1892, vol. 2, p. 145, 1894; Acad. Nat. Sci. Philadelphia Proc. for 1896, p. 470 (name only), pI. 18, figs. 1, 2, 1896. Pseudamusium claibornense Harris, Bull. Am. Paleontology, vol. 9, p; 43, pI. 7, fig. 1', 1897. Conrad in 1865 described this species as follows:
Ovate, very thin in substance; umbo ventricose, narrow, apex acute; anteriorly the larger valve is marked with minute fine lines, having a shagreen-like character. The smaller valve of this species is unknown.
In 1892 Harris briefly described this form under the name P. claibornensis Conrad. Harris suspected and Dall has confirmed the opinion that Conrad's type of P. scintillatus is the young of P. claibornensis. P. claibornensis, as such, never received a formal diagnosis by Conrad. Harris refers to its characteristics as follows:
This rather small, thin Pecten, appearing smooth to the naked eye, when examined under a microscope is found to contain minute ex curving radiate lines, especially near the anterior and posterior margins.
Only one specimen of P. scintillatus is included in the collection from North Carolina.
Locality: Castle Hayne quarry, Pender County, N. C. Geologic horizon: Castle Hayne marl, of Jackson Eocene age.» KELLUM, L. B. 1926. Paleontology and stratigraphy of the Castle Hayne and Trent marls in North Carolina. United States Geological Survey Professional Paper, 143: 1-56, pls. 1-11. [p. 19, 20]
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Pecten scintillatus Con.; G. D. Harris, 1919, Pelecypoda of the St. Maurice and Claiborne Stages, plate 15, figure 14.
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«The species described by Conrad [1] which were received from Dr. Spillman in which he gives the locality ''Enterprise, Miss.," Dr. S. writes me (Aug. 14, 1884) were not found there; he says: "I have no recollection of sending T. A. Conrad any fossils from near Enterprise. I sent him some from Garland's Creek, three miles east of Shubuta, Miss., in the southern part of Clark County." This removes one question, as these shells are undoubtedly Jacksonian and Dr. Meyer is no doubt correct in calling the beds at Enterprise Claibornian.»
[1] Am. Jour. of Conchology, 1865, vol. i, p. 137.
ALDRICH, T. H. 1885. Observations upon the Tertiary of Alabama. The American Journal of Science [Third Series], 30: 300-308. [p. 307]
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