Lyriochlamys bavaricus (Winkler, 1861)
WINKLER, C. G. 1861. Der Oberkeuper nach Studien in den Bayrischen Alpen. Zeitschrift der Deutschen Geologischen Gesellschaft, 13: 459- 521. [p. 469, pl. 5, figs. 12a, 12b]
1861 Pecten bavaricus Winkler, 1861
G. G. Winkler, 1861, plate 15.
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«Die Schale ist 3¼ Centimeter hoch und 2½ Centimeter breit, schief oval, ziemlich gewölbt, mit spitzem Wirbel; den Hauptschalenkörper bedecken ca. 30 Rippen, unregelmässig wechselnd in Dicke und Höhe. Einige entspringen erst unter dem Ende des Wirbels. Auch die Furchen , immer enger als die Rippen, sind ungleich weit. Regelmässig sind in ihrem Verlaufe wohl ausgeprägte concentrische Streifen. Sie stehen enge und biegen in den Furchen immer abwärts.
Die mit Rippen bedeckte Region der Schale trennt an beiden Seiten ein schmaler ungerippter Raum, der spitzig am Wirbel oben beginnt, von den Ohren. Dieser Raum ist vorn mit eigenthümlichen gekrümmten Querstreifen bedeckt, wie gebartet. Das hintere Ohr hat schwache Radialrippen mit concen frischer Streifung.» GUSTAV GEORG WINKLER, 1861
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«Where Lyriochlamys differs from Cenozoic and Holocene Chlamys, however, is in the extent of the inner crossed-lamellar aragonitic inner shell layer. In Lyriochlamys fissicosta and the great majority of Mesozoic "Chlamys," this layer extends nearly to the margins of disk and auricles, whereas in Cenozoic and Holocene true Chlamys it is nearly always confined to the area within the pallial line or is absent altogether except very early in ontogeny. This important difference caused Waller (1991) to apply Sobetski's name Lyriochlamys to the whole array of Mesozoic chlamydids bearing costae or plicae that interlock at the shell margin, leading to rib increase by branching on the right valve and by intercalation on the left. (Note that branching is the negative image of intercalation. So long as ribs interlock at the growing margin when they first form, a branching on one valve will be represented by an intercalation on the opposite valve.) Lyriochlamys also has antimarginal microsculpture, which is particularly evident on the disk flanks in Rhaetian, Jurassic, and some Cretaceous taxa. Data thus far accumulated by one of us (Waller) suggest that Lyriochlamys first appears in the Late Triassic (Rhaetian), as exemplified by species such as Pecten acuteauritus Schafhäutl, 1851, P. bavaricus Winkler, 1861, and P. praepollux Hahn, 1910, and extends through the Jurassic and Cretaceous, becoming extinct at the end of the Cretaceous.»
WALLER, T. R. & L. MARINCOVICH JR. 1992. New species of Camptochlamys and Chlamys (Mollusca: Bivalvia: Pectinidae) from nearthe Cretaceous/Tertiary boundary at Ocean Point, North Slope, Alaska. Journal of Paleontology, 66 (2): 215-227, figs. 1-5. [p. 223]
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