13:45 〜 15:15
[BPT03-P06] Temporal size change of the middle Miocene planktonic foraminifera Paragloborotalia continuosa (Blow, 1959)
キーワード：IODP, Miocene, Size, Planktoinic Foraminifera
Size is basic information for all organisms, a measurable feature in present and fossil. There is a relationship between size and ecological parameters; growth rate, amount of food, lifespan, and death rate. Hypotheses about macroevolution are proposed from fossil records. For example, Lilliput Effect is a phenomenon of size reduction in taxa that experienced strong biostress. Microfossils contribute to test models and hypotheses related to size, because of successful and rich fossil records.
Planktonic foraminifera is marine free-floating, single-celled protozoa classified into approximately 50 species in the modern ocean. The oldest records appeared from the Jurassic. Planktonic foraminiferal shells are well preserved in marine sediments, especially from ocean–drilled cores. The successive and rich appearance of the fossils provides good paleoenvironmental proxies with a high special-temporal resolution by chemical and morphological analyses.
In this study, we reconstructed the temporal size change of the middle Miocene planktonic foraminifera Paragloborotalia continuosa (Blow, 1959) at Integrated Ocean Drilling Program Site U1338 drilled in the eastern equatorial Pacific. To reveal the causes of size change, size data is compared with palaeoceanographic proxies recording drastic climatic change from warm period (Miocene Climatic Optimum) to cool via Mi-3. Then, we will discuss their environmental response shown in size history.
Planktonic foraminifera is marine free-floating, single-celled protozoa classified into approximately 50 species in the modern ocean. The oldest records appeared from the Jurassic. Planktonic foraminiferal shells are well preserved in marine sediments, especially from ocean–drilled cores. The successive and rich appearance of the fossils provides good paleoenvironmental proxies with a high special-temporal resolution by chemical and morphological analyses.
In this study, we reconstructed the temporal size change of the middle Miocene planktonic foraminifera Paragloborotalia continuosa (Blow, 1959) at Integrated Ocean Drilling Program Site U1338 drilled in the eastern equatorial Pacific. To reveal the causes of size change, size data is compared with palaeoceanographic proxies recording drastic climatic change from warm period (Miocene Climatic Optimum) to cool via Mi-3. Then, we will discuss their environmental response shown in size history.