Veprichlamys onzola (Olsson, 1964)
OLSSON, A. A. 1964. Neogene mollusks from Northwestern Ecuador. Paleontological Research Institution, 256 p., pls. 1-38. Ithaca, N.Y. [p. 34, pl. 4, figs. 4-4b]
1964 Chlamys onzola Olsson, 1964
A. A. Olsson, 1964, plate 4.
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«Shell of medium size, high-ovate, equivalve, rhe left, a little more convex than the right, thin. The sculpture is formed by numerous (about 22), little elevated and hardly definable ribs, separared from the adjacent interspace only in that the cord along the summit is larger than the bordering ones: sculptural details on an enlarged scale shown in the figure (Pl. 4, fig. 4b). On the sides, the radial ribs are much smaller and are more sharply spinous. Posterior ear smaller.
Length 35.1 mm., height 40.7 mm., diameter 7 mm. Left valve, Holotype, USNM 644085. The fossil is probably closest to C. lowei (Hertlein), a Recent species from the Gulf of California but is much larger, and judging solely from figures this shell has much finer sculpture. Esmeraldas formations: Quebrada Camerones.» AXEL ADOLPH OLSSON, 1964
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«Waller (1993, p. 236), in a study of the evolutionary origins of tropical American ‘‘Chlamys’’ in both the western Atlantic and eastern Pacific, reported a fossil species closely related to extant ‘‘C.’’ incantata. This species is C. onzola Olsson, 1964, from the early Pliocene Esmeraldas Formation of Ecuador. (See preceding section on Leopecten regarding the age of the Esmeraldas Formation.) The fossil species is known only from the types, a single left valve (USNM 644085, holotype, Fig. 9.5) and an incomplete right valve (USNM 644086, Fig. 9.4), but the shell morphology of these specimens is instructive. The numbers of primary ribs fall within the range of the extant Galápagos species, and the Ecuadorian fossils share the sharp scales and distinctive microsculptural pattern of other species of Veprichlamys.»
WALLER, T. R. 2007. The evolutionary and geographic origins on the endemic Pectinidae (Mollusca: Bivalvia) of the Galapagos Islands. Journal of Paleontology, 81 (5): 929–950. [p. 943]
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Veprichlamys onzola (Olsson, 1964); T. R. Waller, 2007, The evolutionary and geographic origins on the endemic Pectinidae of the Galápagos Islands, figures 9.4, 9.5.
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«Hertlein (1935: 309) compared his new species, Pecten (Chlamys) lowei (= P. vestalis), to several fossil species. These fossil taxa, however, are not closely related, and most are now known to belong to the tribe Aequipectinini. This is also true for Chlamys corteziana Durham, 1950 (see also Moore, 1984:. B22), which Durham (1950, p. 64) thought resembled C. lowei. C. onzola Olsson, 1964, thought by Olsson (1964: 35) to be "probably closest to C. lowei (Hertlein)", is also not closely related. I examined the holotype of Olsson's species and found that it is more closely related to the extant eastern Pacific C. incantata Hertlein, 1972, of the Galápagos Islands. Hertlein (1972) thought that this Galápagos species "bears a general similarity to that of illustrations of P. (Chlamys) nympha Bavay", a species that is now known to be a junior synonym of Spathochlamys benedicti (see above). Sculptural details of both C. onzola and C. incantata, however, indicate that these species both belong in Veprichlamys Iredale, 1929, an Indo-Pacific genus that can be placed in the tribe Chlamydini on the basis of its pre-radial microsculpture and lack of internal rib carinae.»
WALLER, T. R. 1993. The evolution of Chlamys (Mollusca: Bivalvia: Pectinidae) in the tropical western Atlantic and eastern Pacific. American Malacological Bulletin, 10 (2): 195-249. [p. 236]
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