Camptonectes striatopunctatus (Roemer, 1839)
ROEMER, F. A. 1839. Die Versteinerungen des Norddeutschen Oolithen-Gebirges. Ein Nachtrag. iv, 59 p., pls. 17-20. Im Verlage der Hahn'schen Hofbuchhandlung. Hannover, 1839. [p. 27]
1839 Pecten striato-punctatus Roemer, 1839
1870 Pecten arzierensis De Loriol, 1868
1870 Pecten arzierensis De Loriol, 1868
Pecten striato-punctatus, Roemer; F. J. Pictet & G. Campiche, 1868-1871, Descriptions des fossiles du terrain crétacé des environs de Sainte Croix, plate 171, figures 4, 5.
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«P. (Arcuatus) testa orbiculata convexo-plana striis radiantibus arcuatis creberrimis grosse punctatis minoribus alternis, interstitiis latioribus iterum iterumque dichotomis concentrice subtilissime striatis.
Gehört, wie auch die vorhergehende Form, zu den Arcuaten. Die kreisrunden Schalen sind sehr flach gewölbt und mit zahlreichen ausstrahlenden Streifen bedeckt, in denen man grosse Puncte sieht. Ihre Zwischenräume sind etwas breiter, wiederholt dichotom und von zarten concentrischen Streifen bedeckt. Findet sich nur im Hilse, bei SchandeIahe, Schöppenstedt und am EIligserbrinke. Auch aus der Form der Ohren und dem Umfange der Schalen scheinen noch Unterschiede dieser drei, bislang verwechselten Formen hergenommen werden zu können.» FRIEDERICH ADOLPH ROEMER, 1839
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«Variability:
The main variable characteristic in C. striatopunctatus is the sculpture: it varies from numerous very fine punctae to fewer punctae lying further apart and visible to the naked eye. This latter type of sculpture is very close to the finest sculpture of C. virgatus (NILSSON, S., 1827) (see under C. virgatus for PERVINQUIÈRE's opinion on this matter). The specimens with very fine sculpture were described as P. arzierensis by P. DE LORlOL. It is impossible to state the difference in punctae numerically because the visibility of the punctae depends on their size, their place on the disc and the state of preservation of the shell (on poorly preserved specimens no punctae can be seen on the middle parts of the discs). According to P. DE LORIOL the diverging, punctae-bearing striae rarely divide in Pecten arzierensis. Indeed on types and topotypes it is true that the striae do not divide as frequently as they do on specimens with coarser ornamentation. It could be that this is a local variation but there seems no reason to consider it to be outside normal variability. Synonymy: C. striatopunctatus is easily distinguishable from other Camptonectes species; hence little confusion arose in its synonymy. There seems to be no doubt that DE LORIOL's species (P. arzierensis) is synonymous with C. striatopunctatus. Differentiation: C. striatopunctatus is the only Lower Cretaceous Camptonectes species without concentric ornamentation and is thus easily differentiated. Confusion could arise with C. virgatus-specimens with fine sculpture: however, C. virgatus valves are more convex and the punctae-bearing striae lie deeper in the discs. Unfortunately these characteristics cannot be used on poorly preserved specimens. Poorly preserved C. cottaldinus-specimens cannot easily be differentiated from C. striatopunctatus, especially when the auricles are missing (see under C. cottaldinus). The differentiation towards the other Cretaceous Camptonectes-species can be made by using the same characteristics as under C. (Boreionectes) cinctus. Generic attribution: Pecten striatopunctatus ROEMER, F. A. 1839, is similar to Pecten lens J. SOWERBY, the type-species of Camptonectes (AGASSIZ in MEEK); hence its correct name should be Camptonectes (Camptonectes) striatopunctatus (ROEMER, F. A., 1839).» DHONDT, A. V. 1972. Systematic revision of the Chlamydinae (Pectinidae, Bivalvia, Mollusca) of the European Cretaceous. Part 1: Camponectes. Bulletin de l’Institut Royal des Sciences Naturelles de Belgique, 48 (3): 1-60, pls. 1, 2. [p. 16, 17]
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Camptonectes (Camptonectes) striatopunctatus (F. A. Roemer, 1839); A. V. Dhondt, 1972, Systematic revision of the Chlamydinae of the European Cretaceous, Part 1: Camponectes, plate 1, figure 2.
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