Pseudopecten barbatus (J. Sowerby, 1819)
SOWERBY, J. & J. DE C. SOWERBY. 1812-1846. The Mineral Conchology of
Great Britain; or coloured figures and descriptions of those remains of
testaceous animals or shells. 7 vols., pls. 1-648 (and 2 bis). London. [vol. 3, p. 53, pl. 231]
1819 Pecten barbatus J. Sowerby, 1819
1850 Pecten erebus Orbigny, 1850
1868 Pecten coquandi Jaubert, 1868
1886 Pecten limpus Gregorio, 1886
1850 Pecten erebus Orbigny, 1850
1868 Pecten coquandi Jaubert, 1868
1886 Pecten limpus Gregorio, 1886
J. Sowerby, 1819, plate 231.
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«SPEC. CHAR. Orbicular, depressed, transversely striated; rays 14, those upon one valve spinose; spines long, acute, depressed; ears nearly equal.
THE spinose valve is the flattest; the striae upon it are sharp, and much elevated upon the sides of the rays, from whence they curve into the bases of the spines, of which there are about five to each ray. The rays upon the other valve are convex, equal in width to the space between them, and crossed by less elevated striae than those upon the spinose valve. The sides of both valves, near the ears, are perpendicular and neatly pectinated. This remarkable Scallop is from the collection of Mr. Miller, who obtained it from the inferior Oolite of Dundry.» JAMES SOWERBY, 1819
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«2. AMENDED DIAGNOSIS
Distinguished from all other species of Pseudopecten by the presence of long spines on the right valve.
3. AMENDED DESCRIPTION
Disc sub-orbicular in juveniles becoming sub-ovate, longer than high (text fig. 64), near the maximum height of 52 mm (ENSM). Umbonal angle very variable (text fig. 65) but increasing during ontogeny to produce concave dorsal margins. Disc flanks moderately high and ornamented with vertical striae (PI. 2, Fig. 18).
Equilateral; inequivalve, left valve moderately convex, right valve almost flat. Intersinal distance greater in left valve than right. Moderately large byssal notch in right valve becoming relatively smaller during ontogeny. Auricles well demarcated from disc, moderate in size, anterior slightly larger than posterior. Junction with hinge line 90°. Anterior auricle of right valve meeting disc at an acute angle. Posterior auricle of right valve and both auricles of left valve meeting disc at an acute angle. All auricles ornamented with pronounced comarginal striae. Hinge line of right valve bearing dorsally directed spines up to 5 mm in length, spaced at intervals of 2-3 mm (PI. 2, Fig. 17). Exterior of both valves exhibiting 13-14 radial plicae, usually 14 on right valve, 13 on left. Plicae equal in width to sulci, angular on right valve, rounded on left. On left valve both plicae and sulci traversed by comarginal striae (PI. 2, Fig. 16). On right valve only flanks of plicae bearing comarginal ornament but latter more pronounced than on left valve (PI. 2, Fig. 17). At shell heights above about 20 mm plicae on right valve also ornamented with ventrally directed spines up to 10 mm in length, usually spaced at intervals of about 5 mm (PI. 2, Fig. 17). Plicae rectilinear in form on shell interior. Shell thickness moderate. 4. DISCUSSION
Of the two syntypes of 'Pecten' barbatus J. SOWERBY in the BCM, the bivalved specimen (C2281.1) is herein selected as lectotype and the other specimen (C2281.2), a right valve seen from the interior, becomes, ipso facto, the paralectotype. The figure of 'P.' barbatus J. SOWERBY; GOLDFUSS differs markedly from the species described in Section 3 by exhibiting 19 plicae and high H/L and H/UA ratios (1). This may, however, be due to a draughting error and in the absence of the original (apparently destroyed during the 2nd. World War) it is impossible to say whether GOLDFUSS' hypodigm differed from that of J. SOWERBY, and thus whether his use of 'P. ' barbatus should be excluded from the synonymy.»
JOHNSON, A. L. A. 1984. The palaeobiology of the bivalve families Pectinidae and Propeamussiidae in the Jurassic of Europe. Zitteliana, 11: 1-235, pls. 1-11. [p. 80, 81]
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Pseudopecten (Echinopecten) barbatus J. Sowerby 1819); A. L. A. Johnson, 1984, The palaeobiology of the bivalve families Pectinidae and Propeamussiidae in the Jurassic of Europe, plate 2, figures 15-18
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