Ruthipecten Beu & Taviani, 2014
BEU, A. G. & M. TAVIANI. 2013. Early Miocene Mollusca from McMurdo Sound, Antarctica (ANDRILL 2A drill core), with a review of Antarctic Oligocene and Neogene Pectinidae (Bivalvia). Palaeontology, 56 (6): 1-44, figs. 1-9. [p. 313]
«Genus RUTHIPECTEN gen. nov
LSID. urn:lsid:zoobank.org:act:12E6D493-E23D-4E17-BFE6-6E6DA46BDE93
Type species. Chlamys (Zygochlamys) tuftsensis Turner, 1967.
Occurrence of type species. Late Miocene – Early Pliocene, Antarctica.
Derivation of name. Named in fond memory of Ruth (‘Ruthie’) Turner, a great malacologist who devoted her life to MCZ, and who is the author of the type species; combined with the suffix pecten (Latin, a comb), used in the names of many scallops. Gender masculine.
Diagnosis. A genus of Chlamydini with moderate-sized (H 55 mm, a few specimens to H 73 mm), strongly inflated, weakly prosocline, thick shell. Umbonal angle low, c. 105 degrees. LV of most specimens slightly more inflated than RV. Auricles asymmetrical, anterior ones longer than posterior; LV anterior auricle with straight anterior margin, RV anterior auricle with anterior margin moderately deeply embayed by acute byssal notch, which is functional in adults. Macrosculpture of four to nine (five on most specimens) prominent, widely spaced, relatively narrow costae each bearing a few large, sparse, irregularly placed, radially elongate nodes, particularly near ventral margin of disc; several narrow, widely spaced secondary and tertiary radial riblets in each wide interspace, leaving wide interspaces bearing only commarginal sculpture; disc and auricular microsculpture of low, vaguely defined, widely spaced commarginal ridges on most specimens (abraded?). Antimarginal sculpture and preradial microsculpture not seen. Without internal rib carinae; other internal characters not seen.
Included species. Besides Ruthipecten gen. nov. tuftsensis (Turner, 1967), the unnamed species in ANDRILL 2A described below is the only species we refer to Ruthipecten gen. nov.
Remarks. Beu (1985, pp. 7–8) remarked that ‘Chlamys’ tuftsensis is not related phylogenetically to Zygochlamys Ihering, 1907, and to the other species that subsequently were referred to Austrochlamys by Jonkers (2003). However, ‘Chlamys’ tuftsensis was placed in Austrochlamys by Jonkers (2003, p. 66). The genus Ruthipecten is now provided for the distinctive Antarctic scallop in the Prospect and Sørsdal formations and related species. Ruthipecten gen. nov. tuftsensis differs from species of Austrochlamys in its smaller size (most specimens H c. 55 mm, H up to 73 mm, Jonkers (2003, pp. 65–66); compared with up to c. 100 mm for A. natans and 137 mm for A. anderssoni), its more equidimensional shape, its larger auricles with, in particular, markedly longer (antero-posteriorly) posterior auricles, its markedly greater inflation, and in having only four to nine (five on most specimens) major radial costae elevated in prominence above their neighbours, and bearing sparse, radially elongate nodules at irregular intervals down each costa, with one to three, rarely up to five, narrower, secondary radial costae and numerous low, narrow, widely spaced tertiary costellae in the wide interspaces between the prominent costae. Obvious but probably abraded, widely spaced commarginal ridges cross the wide, flat radial interspaces. Little is known of the finer sculptural details. We think it unlikely that Ruthipecten gen. nov. is closely related phylogenetically to Austrochlamys, Leoclunipecten gen. nov. or Zygochlamys, and we do not know its origins.»
ALAN GLENN BEU & MARCO TAVIANI, 2014
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Ruthipecten gen. nov. tuftsensis (Turner); A. G. Beu & M. Taviani, 20014, Early Miocene Mollusca from McMurdo Sound, Antarctica (ANDRILL 2A drill core), with a review of Antarctic Oligocene and Neogene Pectinidae (Bivalvia), figures 5A (holotype, RV), 5B-5F.
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