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Thursday, October 28, 2010

Photo: First Animals Evolved in Lakes, Not Oceans, Study Hints


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Rocks from the Doushantuo formation in southern China (above, researchers collecting samples) contain a mineral called smectite, which forms in salty, alkaline lakes but not seawater, researchers announced in July 2009.

Because Doushantuo also contains fossil embryos of some of the earliest known animals, the find suggests that the first complex animals arose in lakes, not oceans as has been commonly believed.

Photograph courtesy M. Kennedy, UC Riverside