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Research Group Division of GeoEnvironmental Science


Paleo-bioevents and the paleontology Research Group

•Professor Kunio Kaiho,
specializing in Micropaleobiology, Biological extinction event studies, and Paleooceanography
•Assoc. Professor (of Tohoku University Museum) Osamu Sasaki,
specializing in Paleobiology, and Microfossil morphology

Evolution of Earth and life with catastrophic events

Evolution of Earth and life with catastrophic events The evolution of life has never been as monotonous as one might think. In actuality, six periods of biological massive extinction events have prevailed during the past 500 million years. The left-hand side diagram presents results obtained from analyses performed by Prof. Kaiho and others of the fossil assemblages produced in the Cretaceous period and the Tertiary period, biomarkers, and the carbon and oxygen isotopic compositions. Results illustrate that the collision of asteroids onto the Earth, mass extinction, and a halt to life production occurred concurrently. The restoration process from the massive life extinction events is extremely interesting because it can be considered as an assessment of a biosphere’s capability of restoring itself. They also clarified that biotic crises at the end of the Permian, mid-Cretaceous, and the Paleocene-Eocene boundary occurred by global warming and decreases in dissolved oxygen in oceans, using biomarker, carbon and sulfur isotope ratios, and microfossils.

A Treasure Trove of Information––The Tohoku University Museum

Looking at the coral reefs in the South Seas Paradise with a high resolution of environmental history The Tohoku University Museum holds over 2 million academic resources and archives that have been collected since the university was founded. Some properties are exhibited in the Museum of Natural History at Tohoku University also, which are available for anyone to see at any time. The specimens of well-organized fossils, minerals and rocks, are a “map” of the world of nature. The result is just as powerful as the Periodic Table, on which all atoms are aligned ingeniously. All specimens are placed in a database, from which they are available not only for on-campus use but also for people outside the university. http://webdb2.museum.tohoku.ac.jp/data_base/index.htm


Our daily life is deeply convolved with the environments of tidelands and shallow water areas. Assistant Professor Sato is investigating the living history of bivalves with respect to currently living species as well as fossils based on the microscopic growth patterns recognized on the shells. Professor Sato is also examining changes that proceeded in shellfish assemblages after seawater was intentionally stopped from running into the Isahaya Bay of the Ariake Sea in Nagasaki Prefecture as part of a project of land reclamation by drainage.