Word: radiolaria
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Dates: during 1970-1979
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That could explain the sudden disappearance throughout the earth's history of many animal and plant species, from the single-celled, ocean-dwelling radiolaria to the dinosaurs. Thus, Crutzen and his colleagues note, a long-term threat to the ozone layer from any source may well be a threat to the species that now inhabit the earth-including...
...that these reversals may somehow be linked with such old biological puzzles as the sudden disappearance of the dinosaurs some 65 million years ago. Now investigators from Columbia University's Lamont-Doherty Geological Observatory have added new evidence to the old speculations. They report that six species of Radiolaria-tiny marine animals-suddenly became extinct during or shortly after switches in the earth's magnetic poles...
...evidence comes from 28 samples of the sea bottom drilled in the Pacific and Antarctic oceans. After microscopic examinations of half a million individual fossils taken from the deep-sea cores, Paleontologist James D. Hays and Geophysicist Neil Opdyke concluded that two species of Radiolaria became extinct 2.4 million years ago, another about two million years ago, two about 1.8 million and one about a million years ago. The dates, Hays told a meeting of the Geological Society of America, are significantly close to known reversals in the earth's field...
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