Cyclopecten antiquatus (R. A. Philippi, 1844)
PHILIPPI, R. A. 1844. Enumeratio Molluscorum Siciliae cum viventium in tellure tertiaria fossilium, quae in itinere suo observavit. Volumen Secundum, iv, 303 p., pls. 13-28. E. Anton, Halis Saxonum [p. 61, pl. 16, fig. 5]
R. A. Philippi, 1844, plate 16.
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In valle fluminis Lamati valvulas tres inveni.
Testa tenuis, 3½''' longa, 3½''' alta, auricula postica 3¼''' longa, antica 1⅓'" longa, forma suborbicularis, aequilatera, regularis. Superficies elegantissime lineis concentricis regularibus exarata, absque ullo Iinearum radiantium vestigio. Auricula antica radios contra eIevatos exhibet. Pagina interna in una valvula laevissima, in reliquis duabus ad marginem Iineis elevatis radiantibus 12—14 munita. — Etiam in Germania occidentaIi prope Freden occurrit.» RUDOLPH AMANDUS PHILIPPI, 1844
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«antiquatus, Pecten – Philippi, 1844z4: 50; 1844g: 61, 300, pl. 16, fig. 5. Tertiary of Freden & Diekholz, Niedersachsen, Germany [Late Oligocene]. Synonym of Propeamussium pygmaeum (Münster, 1835) (Janssen, 1979b: 47–48). The material he reported in 1844 from a Pliocene locality in Italy (Philippi, 1844g), is probably not the same species.»
COAN, E. V. & A. R. KABAT. 2017. The Malacological Contributions of Rudolph Amandus Philippi (1808–1904). Malacologia, 60 (1-2): 31-322. [p. 60-61]
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«Distribution
Temperate eastern Atlantic on Galicia Bank, Lusitanian and Meteor group seamounts; bathymetric range: present material alive at 805–1160 m. Description
Shell up to Ca 10 mm high, fragile, semitransparent, suborbicular, compressed, slightly inequivalve, nearly equilateral, auricles unequal, diameter of prodissoconch 220 μm (Fig. 9C). Left valve sculptured with primary and secondary radial lines of rounded vesicles or lamellae, usually eroded, sometimes nearly smooth or very weakly sculptured. Auricles rather small, the anterior more prominent, sculptured with small vesicles or lamellae. Right valve quite smooth in early growth stage, later with fine, closely spaced, smooth and shiny commarginal or nearly commarginal lamellae. Posterior auricle continuous with disc with a few lamellae coarser than on the disc. Anterior auricle discontinuous with disc with four to six weak radial riblets and overrunning closely spaced, very coarse lamellae. Hinge line straight, with the lamellae of the anterior auricle forming spinose projections over the hinge line and folding over it. Internal surface with radial riblets commencing in late growth stage and extending towards the shell margin. Byssal notch small, no ctenolium. Remarks
The Plio-Pleistocene fossils described by Philippi (1844) as Pecten antiquatus and P. fimbriatus, based on right and left valves, respectively, have hitherto been considered as synonyms of Cyclopecten hoskynsi (Forbes, 1844) (e.g. Jeffreys 1879; Sabelli & al. 1991). However, Philippi states the presence of 12–14 internal riblets and a size range of 7.6–8.7 mm (3.5–4 german lines), as in our material. Cyclopecten antiquatus can be distinguished from C. hoskynsi, known from the Mediterranean Sea and adjacent eastern Atlantic (Fig. 10D–I), by more numerous radial lines of smaller vesicles. Cyclopecten hoskynsi is somewhat smaller in size and quite homogeneous in sculpture with 10–17 radial sets of large vesicles on the left valve. It lacks internal riblets or, if present, these are seen only in large valves (i.e. 6 mm) and near the shell margins. Cyclopecten imbrifer (Lovén, 1846), from the Arctic and boreal eastern Atlantic (Fig. 10A–C), is a closely related species, which is larger in size (up to Ca 25 mm high) and consistently lacks the internal riblets (relevant material examined in SMNH and ZMUC). It has a weaker sculpture of numerous irregularly spaced radial vesicles, or more rarely only commarginal lamellae, without vesicles [= C. imbrifer var. lamellosus (Posselt, 1898)]. Cyclopecten pustulosus (Verrill, 1873) from the northwestern Atlantic also belongs to this species group. It is larger, up to C. 25 mm high, with more prominent vesicular sculpture and sometimes with internal riblets. Verrill & Bush, in Verrill 1897 introduced the name Cyclopecten subimbrifer based on C. hoskynsi sensu Verrill, 1882 (non Forbes), from the northwestern Atlantic, which is more similar to C. imbrifer. Jensen (1912: 25) treated both as ecomorphological forms of C. imbrifer, and showed that sculpture is very variable. He also enumerated C. imbrifer var. major (Leche, 1878) and C. imbrifer var. minor (Jensen, 1912: 25) from southwest Iceland. Both are also forms of C. imbrifer. DIJKSTRA, H. H. & S. GOFAS. 2004. Pectinoidea (Bivalvia: Propeamussiidae and Pectinidae) from some northeastern Atlantic seamounts. Sarsia, 89: 33-78, figs. 1-22. [p. 45, 47]
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Cyclopecten antiquatus (Philippi, 1844); H. H. Dijkstra & S. Gofas, 2004, Pectinoidea (Bivalvia: Propeamussiidae and Pectinidae) from some northeastern Atlantic seamounts, figures 8A-8H.
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