Carolinapecten eboreus eboreus (Conrad, 1833)
CONRAD, T. A. 1833. On some new fossil and recent shells of the United States. Journal of the Academy of Natural Sciences of Philadelphia, 1st series, 23: 339-346. [p. 341]
1833 Pecten eboreus Conrad, 1833
1843 Pecten micropleura H. C. Lea, 1843
1844 Pecten holbrookii Ravenel, 1844
1943 Chlamys (Lyropecten) planicosta Gardner, 1943
1843 Pecten micropleura H. C. Lea, 1843
1844 Pecten holbrookii Ravenel, 1844
1943 Chlamys (Lyropecten) planicosta Gardner, 1943
Pecten eboreus; T. A. Conrad, 1840, Fossils of the Medial
Tertiary of The United States, plate 23, figure 2 (above); plate 24, figure 3 (below).
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«Shell suborbicular, compressed, thin, a little oblique; ribs about twenty two, rounded, little elevated and smooth ; inferior valve nearly flat. Length, two inches.
Locality.— Suffolk, Va. Upper marine.» TIMOTHY ABBOT CONRAD, 1833
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«42. Carolinapecten eboreus (Conrad, 1833) (Synonyms: Pecten micropleura H. C. Lea, 1843: Pecten holbrookii Ravenel, 1844; Pecten eboreus darlingtonensis Dall, 1898; Pecten eboreus bertiensis Mansfield, 1936; Pecten eboreus watsonensis Mansfield, 1936). Shell medium to large, slightly inflated, with low, undulatoy ribs. Zone l, Middlesex and Surry counties; Zone 2, King and Queen, Isle of Wight, and Southampton counties, Petersburg, Chuckatuck, Suffolk, and Chesapeake. Length 67 mm, height 65 mm. This species is locally abundant, but patchily distributed. Some of the names synonymized above may eventually prove to be valid, at least subspecifically. C. eboreus walkerensis (Tucker, 1934) (synonym: Pecten eboreus buckinghamensis Mansfield, 1939) is an exceptionally large, statigraphically important subspecies with a warped cross section. It is from the upper Goose Creek Limestone of South Carolina, and was erroneously synonymized with Carolinapecten eboreus senescens (Dall, 1898) by Mansfield, 1936. The latter is a small subspecies with obsolete sculpture which is restricted to the Waccamaw faunas.»
CAMPBELL, L. D. 1993. Pliocene molluscs from the Yorktown and Chowan River Formations in Virginia. Virginia Division of Mineral Resources Publication, 127: 1-259, pls. 1-43. [p. 24]
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Carolinapecten eboreus; L. D. Campbell, 1993, Pliocene molluscs from the Yorktown and Chowan River Formations in Virginia, plate 4, figure 42.
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«DISCUSSION.— The type specimen(s) are apparently lost. Richards (1968) did not record the type specimens as being at the Philadelphia Academy. Moore (1962:57) recorded the specimens as missing from the Academy. Conrad's type locality for this species is Suffolk, Virginia. We have selected a specimen from this locality to be the neoholotype (USNM 204134). This articulated specimen was collected from the right bank ofthe Nansemond River at Suffolk, Suffolk 7.5' quadrangle, Virginia, from the cliffs exactly 0.5 miles (0.8 km) east of the crossing of Route 460 over the river. The sample was collected from 6 feet (1.8 m) above the beach in a fine sand of the upper part of the Yorktown Formation (presumably the same age beds in Conrad's sampled units). The dimensions of the neoholotype are 53.8 mm (height), 56.2 mm (length), 9.4 mm (convexity of left valve), and 7.8 mm (convexity of right valve). The right valve has 22 ribs. Conrad's original description of this species as being thinshelled, about 22 ribs, rounded, little elevated and smooth with a flatter right valve, closely coincides with the selected neotype and with other specimens collected from this locality. Conrad mentioned that his specimen is 2 inches (5.0 cm) long, which is slightly more than 50 mm and close to the size ofthe selected neotype. Many ofthe best-preserved specimens from this locality are of this small size, and the larger specimens common at other localities are rare in these beds at Suffolk.
The various subspecies and species that we have synonomized and that were synonomized by Waller (1969) are apparently geographic variants or local ecologic variants. The specimens of this species at the type locality differ from those at Lee Creek in being smaller, with more numerous, narrow ribs which have more highly crenulated, microscopic growth striae and less tendency to form riblets in the interspaces. Thirty-eight topotypes (USNM 204135), whose measurements are given below, are deposited with the neotype at the National Museum of Natural History, Smithsonian Institution. MEASURED MATERIAL.— Measurements (in mm) of 38 topotypes (USNM 204135) from Suffolk, Virginia, are given below: Length Height Convexity
LEFT VALVES
RIGHT VALVES
FIGURED SPECIMENS.— USNM 203901 from USGS 25364 (Plate 6: figure 1), USNM 203902 from USGS 25362 (Plate 6: figures 2, 3), USNM 203903 from USGS 25360 (Plate 6: figures 4-6), USNM 203904 from USGS 25364 (Plate 6: figure 7), and USNM 203905 from USGS 25364 (Plate 6: figures 8, 9). Neoholotype, USNM 204134 from USGS 25724A (Plate 7: figures 9-11).
OCCURRENCE.— This species is common at section 5, units B, C, D, and E. It also occurs at sections 2 (D, E), 3 (D, E), 4 (D, E), 6 (C). TYPE LOCALITY.— Suffolk, Virginia (Yorktown Formation).» WARD, L. W. & B. W. BLACKWELDER. 1987. Late Pliocene and Early Pleistocene Mollusca from the James City and Chowan Rives Formations at Lee Creek Mine. In: Geology and Paleontology of the Lee Creek Mine, North Carolina, II, C. E. Ray (ed.), Smithsonian Contributions to Paleobiology, 61: 113-283, pls. 1-47. [p. 141, 142]
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Carolinapecten eboreus (Conrad); L. W. Ward & B. W. Blackwelder, 1987, Late Pliocene and Early Pleistocene Mollusca from the James City and Chowan Rives Formations at Lee Creek Mine, plate 6, figures 1-9; plate 7, figures 9-11.
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