Spondylopecten cardinatus (Quenstedt, 1857)
QUENSTEDT, F. A. 1856-1858. Der Jura. 823 p., pls. 1-100. H. Laupp’schen, Tübingen [p. 627, pl. 78, fig. 1]
1857 Pecten cardinatus Quenstedt, 1857
1883 Pecten spinicostatus Whidborne, 1883
1883 Pecten spinicostatus Whidborne, 1883
F. A. Quenstedt, 1856-1858,
plate 78. |
«Werden die Formen größer, dann treten zwar Unsicherheiten in der Bestimmung ein, doch will ich noch einen davon als
Pecten cardinatus Tab. 78, Fig. 1 unterscheiden. Der Form nach schließt er sich an globosus Fig. 2 an, aber feine Rippen sind viel breiter. Ich würde ihn dennoch globosus y genannt haben, wenn nicht der Name 'eingezapft' passend auf die Schloßzähne anspielte, welche ich bereits in Handb. Petref. Pag. 507 nachwies. Diese Zahnung des Schlosses ist bei verkieselten so eigentümlich, daß vielleicht später daraus eine besondere Gruppe Cardinaten gemacht werden kann. Kann ich auch bei diesen Verkalkten die Zähne nicht nachweisen, so ist wegen der Analogie an der Existenz nicht zu zweifeln. Die Rippen sind schmal, sehr erhaben, und zu beiden Seiten gehen in den Furchen eigentümliche Zähnchen herab, die sich nicht berühren. Nur in der Jugend scheinen diese Zähnchen wie bei subpunctatus die ganze Furche zu füllen.» FIEDRICH AUGUST QUENSTEDT, 1857
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«2. AMENDED DIAGNOSIS
Distinguished from all other species of S. (Spondylopecten) by the number of plicae (42-48).
3. AMENDED DESCRIPTION
Essentially similar to S. (S.) subpunctatus. Differing by the diagnostic larger number of plicae (see Section 2), whose range of variation, if anything, increases phyletically (see Section 10) and by the generally higher umbonal angle, whose range of variation is from 91° (BM 66825) to 107° (BM L84341).
There is insufficient data to chart phyletic changes in umbonal angle and convexity; C/H for Bajocian forms is plotted in text fig. 87. The maximum height is 33.5 mm (BM L41934). 4. DISCUSSION
The original description of 'P.' cardinatus QUENSTEDT (see Section 1) does not specify the number of plicae but the figure shows about 36, which suggests that it might be an extreme representative of S. (S.) subpunctatus. There seem to be no traces of the original to the figure (or of any other type specimens) in the QUENSTEDT Collection (GPIT) and it may be lost. However, STAESCHE (1926) probably had access to the specimen and applied the name to forms with about 45 plicae, as in the species described in Section 3. If it could be established beyond reasonable doubt that QUENSTEDT's type material is lost the most sensible course would be to designate a neotype in conformity with STAESCHE's hypodigm. Until this is done the species described in Section 3 can only provisionally be accorded the name S. (S.) cardinatus.
The sole observed syntype of 'P.' spinicostatus WHIDBORNE (BM 66825; PI. 3, Fig. 21) possesses about 45 plicae and in its convexity (1) and number of spine rows (2) is indistinguishable from S. (S.) cardinatus. Of the specimens which YIN (1931) placed in 'P.' cordiforrnis GEMMELLARO and DI BLASI, only one, with 60 plicae, is referable to that species (= S. (S.) globosus). The remainder, with 42-48 plicae, are inseparable from S. (S.) cardinatus. 5. STRATIGRAPHIC RANGE
Although a long-lived species S. (S.) cardinatus is only known from a few disjunct records. The earliest is from the Parkinsoni zone (U. Bajocian) of the Cotswolds where at least seven specimens (see Section 7) have been found. STAESCHE (1926) states that the species occurs sporadically in the Oxfordian and Kimmeridgian of S. Germany but it would seem that only two specimens have actually been recovered, one from the U. Oxfordian (GPIT) and one from the Kimmeridgian (STAESCHE's measured specimen). A further two specimens (GPIT, BM 49199) are known from the L. Tithonian of the same area. 15 specimens are recorded from the U. Tithonian of S. France (YIN, 1931).
6. GEOGRAPHIC RANGE
S. (S.) cardinatus is unknown outside Europe. Within Europe, records are widespread but patchy (see Section 5). They seem to indicate a gradual southward migration.»
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. 102, 103]
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Spondylopecten (Spondylopecten) cardinatus (Quenstedt, 1858); A. L. A. Johnson, 1984, The palaeobiology of the bivalve families Pectinidae and Propeamussiidae in the Jurassic of Europe, plate 3, figures 20, 21.
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