Fossil guava from the flowering plant genus Paleomyrtinaea (shown here are seeds as seen through a microscope) was one of several fossils used to calibrate the molecular clock in a University of Florida study that estimates the radiation of the rosid clade to be about 90 million years ago. This radiation set the stage for the diversification of other plant and animal species. The study appeared in the online edition of the Proceedings of the National Academy of Sciences journal the week of Feb. 9.
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Return to: UF study: Rapid burst of flowering plants set stage for other species