Spondylus fimbriatus 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. 97, pl. 106, figs. 2a, 2b]
1833 Dianchora spinosa Woodward, 1833
1835 Spondylus fimbriatus Goldfuss, 1835
1847 Spondylus dutempleanus Orbigny, 1847
1877 Dianchora matvejevae Sobetski, 1977
1835 Spondylus fimbriatus Goldfuss, 1835
1847 Spondylus dutempleanus Orbigny, 1847
1877 Dianchora matvejevae Sobetski, 1977
A. Goldfuss, 1833-1840, plate 106.
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Spondylus testa oblique ovato-orbiculari, valva dextra plana margine efuso-affixa, sinistra convexa, costulis subaequalibus confertis, spinis sparsis compressis erectis. — E creta alba Herciniae. M. B.
Die untere Schale dieser Muschel ist mit auslaufenden Randfalten auf andere Körper angewachsen. Beide Schalen haben einen schief-oval-kreisförmigen Umfang und sind fein concentrisch gestreift. Die linke ist convex und hat flache, zahlreiche, gedrängte, kleine Rippen, welche vom vorderen Rande bis zur Mitte dicht aneinander stossen und kaum merklich abwechselnd grösser und kleiner sind, während die von der Mitte bis zum hinteren Rande etwas breiter werden und mehr von einander abstehen, so dass sich zwischen mehreren derselben in der Zwischenfurche eine schmale Linie erhebt, welche in unserer Zeichnung nicht ausgedrückt ist. Verhältnissmässig dicke, aufrechte, zusammengedrückte Stacheln stehen einzeln und zerstreut auf den Rippen. — Aus der weissen Kreide bei Quedlinburg.»
AUGUST GOLDFUSS, 1835
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«Description. Regular oval, slightly oblique, convex shells. Right valve can be the most inflated, but is generally flatter because it was attached to a substratum; its attached area has concentric ornament, but the free shell is ornamented by nearly equal radial ribs separated by narrow grooves; short, irregularly placed spines occur on the ribs. Left valve ornamented by numerous, slightly irregular, radial ribs which give it a 'wavy' appearance; these irregularly bear numerous spines of varying sizes and angles.
Remarks. Previously recorded as S. dutempleanus d'Orbigny, but owing to the considerable variability that occurs in both the ribs and spines ornamenting spondylids, this species is now treated as a junior synonym of S. fimbriatus Goldfuss (Dhondt and Dieni 1990). Occurrence. Cenomanian-Campanian; localities at all horizons in the counties around London, and from Devon and Dorset to 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. 131, 132]
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Spondylus fimbriatus Goldfuss; R. J. Cleevely & N. J. Morris, 2002, Introduction to molluscs and bivalves, plate 22, figure 3.
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«Discussion: Spondylus species to-day are restricted to tropical, subtropical, and warm temperate seas (including the Mediterranean, and Bay of Biscay). In the Cretaceous they reached higher latitudes and were found on the eastern side of the Atlantic as far north as Sweden (which incidentally is also true of rudists f.i.). Therefore, we assume that during the Cretaceous the ecological requirements were identical to those of to-day, and that the variability of Spondylus species is comparable. To assess the width of the variability we chose the type species of the genus Spondylus, Sp. gaederopus LINNÉ, in a sample from Annaba (formerly Bône), in Algeria (Institut royal des Sciences naturelles de Belgique, Zoology, Dautzenberg Coll. IG 10591), including specimens of different sizes, and in an assortment of specimens found on the north-eastern Sardinian coasts. On these specimens we noted that:
— shells vary in shape from circular to elongated-oblique; — intercalary ribs are sometimes numerous and sometimes few, their strength varies to such a degree that on some valves the primary and secondary ribs are of the same strength whereas on others they represent two different series; — spines vary greatly in number and size; small or large they can be present on almost all ribs, or a few large or small ones can be randomly distributed on primary and/or secondary ribs, or they can be virtually absent; — convexity of both valves varies, as is seen in all extensively sessile bivalves. These observations on a recent Spondylus species (confirmed by the great number of varieties existing in literature for that species; see NORDSIECK, 1969, p. 56) allow us to accept that, as stated in the description above, the Cretaceous Spondylus fimbriatus strongly varies in shape, a feature it has in common with other sessile bivalves, which have to adjust to the space available on the substrate. Specimens living on a flat or convex surface (such as the halotype of Sp. fimbriatus, which is adhering to a small echinoid) develop spines or buttresses on the right valve, but those which have found an appropriate concave location do not need supplementary structures to achieve the necessary convexity (as on the Passo del Brocon inoceramid specimen; pI. III, figs. 1-6). The ornamentation i.e. the number of ribs and of spines varies but to quantify this variability is almost impossibile: number of ribs could theoretically be counted, but the number of spines depends not only on the normal variation, but also on the preservation of the specimen and on the quality of its preparation. It is difficult to count the ribs because they are not always continuous and of very variable width; their number changes with the size of the specimen and may depend on the environmental conditions. This undoubted wide variability has convinced us that Sp. fimbriatus GOLDFUSS, 1835 and Sp. dutempleanus D'ORBIGNY, 1847, from the Campanian of the Paris Basin, are synonymous. Already WOODS (1901, p. 126) stated that the only difference appeared to be "in the fewer spines on the ribs". The number of spines is such a variable characteristic in recent Sp. gaederopus that to distinguish species on it seems not to be totally reasonable. Beyond the number of spines, the figures in GOLDFUSS (1835, pI. 106, figs. 2a, b) differ from Sp. dutempleanus in having relatively fewer ribs, but from the halotype it can be seen that there are more ribs present than were drawn, and thus this distinction also disappears. Dianchora spinosa WOODWARD, 1833, from the uppermost Campanian of Norfolk, is known from a relatively poor figure only and is probably identical with Sp. fimbriatus, but until the WOODWARD type has been found this cannot be ascertained definitively; in any case it would be an invalid name as it is a junior secondary homonym of Spondylus spinosus (J. SOWERBY, 1814) (ICZN, art. 59 b). Spondylus arrialoorensis STOLICZKA, 1871, from the Upper Cretaceous of India, seems similar to Sp. fimbriatus, and is quite similar to the Passo del Brocon specimens; yet, not having seen this Indian specimen we cannot be certain that the two taxa are synonymous.» DHONDT, A. V. & I. DIENI. 1990. Unusual inoceramid-spondylid association from the Cretaceous Scaglia Rossa of Passo del Brocon (Trento, N. Italy) and its palaeoecological significance. Memorie di Scienze Geologiche, 42: 155-187, pls. 1-3, figs. 1-10. [p. 171, 172]
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Spondylus fimbriatus Goldfuss; A. V. Dhondt & I. Dieni, 1990, Unusual inoceramid-spondylid association from the Cretaceous Scaglia Rossa of Passo del Brocon (Trento, N. Italy) and its palaeoecological significance, plate 3, figures 1-6.
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