The mode of life and taxonomic relationship of a Japanese Miocene pectinid bivalve Nanaochlamys notoensis

この論文をさがす

著者

抄録

The mode of life of the Japanese Miocene bizarre pectinid Nanaochlamys notoensis (Yokoyama, 1929) is postulated on the basis of functional morphologic and biometric examinations of a large sample from the Middle Miocene Moniwa Formation in northern Japan. This species exhibits a remarkable ontogenetic change of shell morphology; i.e., the weight of valves becomes negatively allometric to the cube of shell size, indicating relative thinning of the shell with growth. Following this allometric change, the umbonal angle increases, the auricles become symmetrical, and the ctenolium disappears. Comparison of shell morphology with Recent pectinids strongly suggests that the present species changed its life style from byssally attached to free-living during ontogeny. This pectinid probably could swim in the later growth stage, but its swimming ability appears to have been poor in view of the high convexity of the left valve. Secondary flaring of the shell and splitting of the first-order plicae are apomorphic features in N. notoensis, suggesting that this species is not a direct ancestor of the extant North Pacific pectinid Swiftopecten swiftii, with seemingly similar overall shell morphology.

収録刊行物

  • Paleontological research

    Paleontological research 10(1), 1-10, 2006-04-30

    日本古生物学会

参考文献:  22件中 1-22件 を表示

各種コード

  • NII論文ID(NAID)
    110004729545
  • NII書誌ID(NCID)
    AA11137385
  • 本文言語コード
    ENG
  • 資料種別
    ART
  • ISSN
    13428144
  • NDL 記事登録ID
    7926811
  • NDL 雑誌分類
    ZM49(科学技術--地球科学--地質)
  • NDL 請求記号
    Z54-J142
  • データ提供元
    CJP書誌  NDL  NII-ELS 
ページトップへ