Syncyclonema nilsoni (Goldfuss, 1835)
GOLDFUSS, A. 1833-1840. Petrefacta Germaniae tam ea, quae in museo universitatis regiae Borussicae Fridericiae Wilhelmiae Rhenanae servantur quam alia quae cunque in museis hoeninghusiano, muensteriano aliisque extant, iconibus et descriptionibus illustrata. Zweiter Theil, 312 p., pls. 1-199. Arnz & Co., Düsseldorf [p. 76, pl. 99, fig. 8a, 8b]
1835 Pecten nilsoni Goldfuss, 1835
A. Goldfuss, 1833-1840, plate 99.
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«Fig. 8. a. Valva sinistra et Die linke und
b. dextra. rechte Schale. Pecten testa subaequivalvi aequilaterali subsemicirculari tenuissima laevi nitida, striis concentricis subtilissimis, auriculis rhomboidalibus difformibus, anteriore valvae dextrae elongata basi profunde sinuata.
Pecten orbicularis. P. testa orbiculari tenuissima coneentrice striata depressa rostri dorso subelato, auriculis aequalibus maiusculis basi latioribus. Nilson, l. c. pag. 23. tab. 10. fig. 12. E creta tophina montis St. Petri. M. B. Gleichklappig, gleichseitig, fast halbkreisförmig, sehr flach und dünn, glatt und glänzend, mit sehr feinen, fast verwischten, gedrängten concentrischen Streifen. Die Ohren sind massig gross, parallel etwas schief abgeschnitten, das vordere der rechten Schale ist verlängert und ausgebuchtet. — Findet sich im Kreidetuff bei Mastricht.»
AUGUST GOLDFUSS, 1835
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«Description. Large, smooth, flattened shell with concave apical margins and curved hinge margins; subequal auricles. Ornamented by concentric growth lines. Anterior auricle of right valve large and wing-like with deep byssal sinus.
Remarks. Distinguished by its larger size, wider apical angle of 93-123 degrees (average 111 degrees), and curved apical margins. The chlamyid shape and byssal sinus serve to separate it from species of Entolium. In most Syncyclonema species the radial Camptonectes-like vermiculations are not visible without magnification of at least x25. Occurrence. Campanian, G. quadrata Zone; Hampshire and Norfolk.» CLEEVELY, R. J. & N. J. MORRIS. 2002. Introduction to molluscs and bivalves. In A. B. Smith & D. J. Batten (Eds.): Fossils of the Chalk, 99-160. The Paleontological Association. London. [p. 126, 127]
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Syncyclonema nilssoni (Goldfuss); R. J. Cleevely & N. J. Morris, 2002, Introduction to molluscs and bivalves, plate 20, figure 6.
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«DESCRIPTION: Medium to large-sized Syncyclonema-species with strongly developed commarginal growth lines and a very wide apical angle; auricles strongly unequal on right valve, subequal on left valve.
DISCUSSION: the specimens from Lonzee though poorly preserved, clearly show the characteristics known from the extensive material at the Sint Pietersberg near Maastricht (DHONDT, 1971).
DISTRIBUTION: Syncyclonema nilsoni has been recorded from ? Cenomanian to terminal Maastrichtian outcrops in temperate European strata.»
MALCHUS, N., A. V. DHONDT & K.-A. TRÖGER. 1994. Upper Cretaceous bivalves from the Glauconie de Lonzee near Gembloux (SE Belgium). Bulletin de l’Institut royal des Sciences naturelles de Belgique, Sciences de la Terre, 64: 109-149. [p. 129]
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Syncyclonema nilsoni (Goldfuss, 1835); N. Malchus, A. V. Dhondt & K.-A. Tröger, 1994, Upper Cretaceous bivalves from the Glauconie de Lonzee near Gembloux, plate 1, figure 4.
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