Azumapecten Habe, 1977
HABE, T. 1977. Systematics of Mollusca in Japan. Bivalvia and Scaphopoda. Zukan no Hokuryukan. Tokyo, Japan. 372 p. (in Japanese). [p. 82]
«Shell of small to moderate size; right valve rather inflated, with irregular, spiny radial ribs: left valve rather compressed: anterior and posterior auricles intercalating a beak between them, rather large: posterior auricle rather oblique: byssal notch on anterior part of right valve»
TADASHIGE HABE, 1977
(Translated by T. Matsubara, 2002) |
Scaeochlamys farreri (Jones & Preston, 1904); B. K. Raines & G. T. Poppe, A Conchological Iconography, The Family Pectinidae, plate 176, figures 1-3.
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«Genus Chlamys [Röding, 1798]
Subgenus Leochlamys MacNeil, 1967 Leochlamys, MacNeil, 1967, p. 9-10.
Azumapecten, Habe, 1977, p. 82. Type species. — Chlamys (Leochlamys) tugidakensis MacNeil, 1967, by original designation. Unnamed "Pliocene" in Tugidak Island, Alaska. U.S.A.
Discussion. — Habe (1977) proposed the subgenus Azumapecten on the basis of the following description: "Shell of small to moderate size; right valve rather inflated, with irregular, spiny radial ribs: left valve rather compressed: anterior and posterior auricles intercalating a beak between them, rather large: posterior auricle rather oblique: byssal notch on anterior part of right valve" (translated from Japanese by the present writer). Pecten (Chlamys) farreri Jones and Preston, 1904, living in the Northwest Pacific was designated as the type species. The original description of Azumapecten involves several obscurities in the diagnosis and is not associated with any comparison to allied genera or subgenera. However, many malacologists have treated Azumapecten as a valid genus or subgenus (e.g. Habe, 1981: Waller, 1993; Hayami and Matsumoto, 1995; Wang, 1996; Higo et al., 1999; Hayami, 2000). On the other hand, MacNeil (1967) proposed the subgenus Leochlamys which was typified by Chlamys (Leochlamys) tugidakensis MacNeil, 1967. MacNeil (1967) and Sinelnikova (1975) also referred "Chlamys nipponensis Kuroda" (= P. (C.) farreri) to the subgenus Leochlamys. Indeed, the large anterior auricle, deep byssal notch, relatively strong ctenolium, irregular spiny radial ribs on shell surface, shagreen microsculpture at least on interspaces of ribs, and absence of distinct crenulations on the inner ventral margin are common to both subgenera. Consequently, Azumapecten Habe, 1977, is a junior synonym of Leochlamys MacNeil, 1967.» MATSUBARA, T. 2002. Molluscan fauna of the "Miocene" Maéjima Formation in Maéjima Island, Okayama Prefecture, southwest Japan. Paleontological Research, 6 (2): 127-145, figs. 5, 6. [p. 139]
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«5) Azumapecten seems to be a widely distributed genus in the Indo-West Pacific realm including temperate seas of both hemispheres. The constituent species of this genus have been regarded as belonging to Chlamys (s. l.) or the Chlamydinae, but it has been questioned whether this genus is phyletically more intimate to such tropical-subtropical species as Laevichlamys squamosa. Our mtDNA analysis clearly indicates that Azumapecten (at least its type-species A. farreri) is more closely related to C. islandica than to L. squamosa.»
MATSUMOTO, M. & I. HAYAMI. 2000. Phylogenetic analysis of the family Pectinidae (Bivalvia) based on mitochondrial cytochrome c oxidase subunit I. Journal of Molluscan Studies, 66: 477-488. [p. 483]
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