Somalipecten pseuduloa (Eames & Cox, 1956)
EAMES, F. E. & L. R. COX. 1956. Some Tertiary Pectinacea from East Africa, Persia, and the Mediterranean region. Proceedings of the Malacological Society of London, 32 (1): 1-68, pls. 1-20. [p. 19, pl. 6, figs. 1-3]
1956 Chlamys (Aequipecten) pseudola Eames & Cox, 1956
F. E. Eames & L. R. Cox, 1956,
plate 6. |
«Material:— Sample PEK.4547 (Kuh Derbak; Pliocene/U. Fars (U. Miocene)), the holotype (L.86086) and 9 paratypes (including L.86087-9).
Description:— Of large-medium size, height and length nearly equal; inflation moderate, Ieft valve slightly the more convex; ventral margin strongly convex. Antero-dorsal and postero-dorsal margins rather strongly concave, their angle of divergence varying in different specimens, increasing from 90°-100° sometimes to as much as 130°. Posterior ears large, approximately right-angled, but with a more or less convex outer margin; left anterior ear only slightly smaller than the posterior, almost right-angled in general shape, but with a strongly sigmoidal outer margin; right anterior ear broad and not very elongate, with the byssal notch rather shallow in full-grown specimens, apparently deeper in earlier growth-stages. Ctenolium often obscure, with about 5 teeth. Right anterior ear with about 4 obscure threads; other ears unornamented or with a few obscure threads. Both valves with about 9 simple, rounded ribs which are prominent in early growth-stages, but which almost, or in some cases completely, fade away near the ventral margin in full-grown specimens; intervals of about the same width as the ribs on the left valve, but only one-half of their width on the right; no subsidiary ornament except fine, regular growth-threads, preserved on uneroded specimens, and occasional obscure radial threads. Dimensions:— Holotype: H = 72.5 mm. L = 74.2 mm. Paratype: H = 72.8 mm. L = 79.0 mm. Remarks:— C. (A.) uloa (King) (35, p. 72, PL.11, figs.9, 11, 12), from beds dated as Burdigalian in Zululand, is smaller, its left valve has no fine grooves in the intervals between the ribs, its right valve has faint subsidiary threads developed on both ribs and intervals, and the ribs, especially the flanking ones on the left valve, are less massive. We are indebted to Professor King for the gift of topotypes to confirm these points. C. (A.) isthmica (Fuchs), from the Pliocene of Egypt, has fewer and more persistent ribs.» FRANK EVELYN EAMES & LESLIE REGINALD COX, 1956
|