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1990 Fiscal Year Final Research Report Summary

Biometrical Study of Morphological Variations of Microfossils in Time and Space

Research Project

Project/Area Number 63480027
Research Category

Grant-in-Aid for General Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field Stratigraphy/Paleontology
Research InstitutionTohoku University

Principal Investigator

ISHIZAKI Kunihiro  東北大学, 理学部, 助教授 (90004316)

Co-Investigator(Kenkyū-buntansha) MARUYAMA Toshiaki  山形大学, 教養部, 助教授 (70165950)
KAIHO Kunio  東北大学, 理学部, 助手 (00143082)
HASEGAWA Shiro  東北大学, 理学部, 助手 (90142918)
TAKAYANAGI Yokichi  東北大学, 名誉教授 (70004299)
Project Period (FY) 1988 – 1990
KeywordsMicrofossils / Foraminifers / Ostracodes / Diatoms / Biometry / Morphological variation
Research Abstract

The purpose of this research is to appraise the morphological variation of microfossils, including foraminifers, ostracodes and diatoms, in time and space, as well as to clarify the vicissitudes of microfossils through Cenozoic time. In 1988, we installed an image processor recently improved, and then have been engaged in selecting parameters suitable for measuring and setting off the morphological variations of microfossils among and within species in each of the above groups. Among pieces of our work accomplished since the second year are the following, although recent progress in our research will be contained in the collected papers, running into 60 pages, annexed to "the report on the results of our research" : Diatoms- Denticulopsis, a biostratigraphically important genus, includes several species which are difficult to be assigned to one or the others. This calls for biometrically laying foundations valid for their classification. In consequence, the length and width were measured, together with counting chambers, of each of the bands. The results show that with respect to D. lauta, the majority of bands have odd numbers of chambers, with a maximum number of 3 or 5 ; the existence of three types as to the arrangement of apical pseudosepta appearing at the ends of a band ; greater importance of chamber numbers and apical pseudosepta in analyzing their life cycles ; positive correlations between the length of and chamber numbers on bands, which indicate the possibility that the cell division gives rise not only to a reduction in the length of bands, but also to the modifications of their structures. Ostracodes- The regional extinction of stracode species due to a vicariance event caused by sea level fluctuations during the Pleistocene might involve ecological constraints which seem to be reflected on their dwarf carapaces, as exemplified by Sinocytheridea latiovata.

  • Research Products

    (12 results)

All Other

All Publications (12 results)

  • [Publications] 長谷川 四郎: "Pseudononion japonicum Asanoの形態変異とその分類学的意義(発表予定)" 化石. 50. (1991)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 入月 俊明・石崎国煕: "Baffinicythere属(貝形虫)の網状装飾の形態解析" 化石. 50. (1991)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 石崎 国煕: "Sea level change in midーPleistocene time and effects on Japanese ostracode fauna" Bulletin of Marine Science. 47. 213-220 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 丸山 俊明: "生物測定にもとづく珪藻化石 Denticulopsis lauta の形態解析ー大きさと形による種の認職ー" 化石. 44. 33-43 (1988)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 丸山 俊明・岩井 雅夫: "ケンゲレン海台と三陸沖の珪藻化石の大きさくらべ" 月刊海洋. 22. 277-282 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 高柳 洋吉: "微化石による古環境解析ーそのアプロ-チにおける諸問題" 応用地質. 29. 38-39 (1988)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Hasegawa, S. :"Morphological variations of Pseudononion japonicum Asano and its implications for taxonomy." Fossils (Palaeont. Soc. Japan),. 50,. (1991)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Irizuki, T. and Ishizaki, K. :"Morphometrics of reticulations of the genus Baffinicythere." Fossils (Palaeont. Soc. Japan),. 50,. (1991)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Ishizaki, K. :"Sea level change in mid-Pleistocene time and effects on Japanese ostracode faunas." Bulletin of Marine Science,. 47,. 213-220 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Maruyama, T. :"Morphological analysis of the fossil diatom Denticulopsis lauta on the basis of biometry -recognition of species by size and shape-." Fossils (Palaeont. Soc. Japan),. 44,. 33-43 (1988)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Maruyama, T. and Iwai, M. :"Comparative study of the size of fossil diatoms from the Kerguelen Plateau and off the coast of Sanriku." Monthly Ocean,. 22(5),. 277-282 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Takayanagi, Y. :"Paleoenvironmental analysis by means of microfossils -Problems in approaches-." Jour. Japan Soc. Eng. Geol.29(4),. 38-39 (1988)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1993-08-12  

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