10:30 〜 10:45
[MIS25-06] 遠洋域環境復元の代替指標としての放散虫形態：問題点と展望
キーワード：放散虫, 分類, 種概念, 形態多様性, 遠洋域
Late Paleozoic and Mesozoic radiolarian cherts are widely distributed within accretionary complexes in the Circum-Pacific and Alps-Himalaya orogenic belts. These cherts are materials for reconstructing the paleoenvironment of the Panthalassa and the Tethys. Many proxies have been developed to elucidate the environment of the past pelagic realm. Species diversity in radiolarian assemblages is expected to be one of proxies for monitoring paleoenvironmental change. However, the species concept of radiolarians is not always consistent throughout the Phanerozoic time. This makes a serious problem to use radiolarian diversity for elucidating environmental fluctuations. This paper documents the present status of taxonomy for Mesozoic and recent radiolarians. Detailed morphological analysis of radiolarian tests and the understanding of the morphogenesis through culture work are clues toward reconstructing pelagic environments in the past oceans.