(USA Today) - A mysterious underwater continent is gradually giving up its secrets.
The latest expedition to Zealandia, a sunken continent long lost beneath the ocean, uncovered 60-million-year-old specimens that reveal a dramatically different geography and climate in the past, said Jamie Allan of the U.S. National Science Foundation.
The latest discovery follows a February announcement that the mostly submerged land just east of Australia qualified as a continent. The boot-shaped region, about the size of greater India, contains New Zealand and New Caledonia, an island to the north. About 94% of Zealandia is underwater.
A team of 32 scientists from 12 countries recently took a nine-week voyage to study the continent's geography, volcanic history, past climates and previous life forms.
Scientists identified more than 8,000 specimens and several hundred fossils by drilling ice cores, said Gerald Dickens, the expedition's co-chief scientist. They discovered microscopic shells of organisms that lived in warm, shallow seas, and spores and pollen from land plants — signs indicating Zealandia was likely much shallower than it is now.
Researchers aren't exactly sure how Zealandia split from Australia but know it broke off about 40 to 50 million years ago.
Further studies of the sediment cores drilled during the latest expedition will focus on understanding how Earth's tectonic plates move and the inner workings of the global climate system.
Records of Zealandia's history, expedition scientists said, will also provide a sensitive test for computer models to predict future changes in climate.