Based on earlier studies, biologists believed that the vast majority of today's frogs originated in a blossoming of new species 100 million years ago. New and more complete genetic data pinpoints this radiation much earlier: 66 million years ago at the Cretaceous-Paleogene boundary, precisely when much of life on Earth was wiped out by a comet or asteroid. Frogs took advantage of flourishing angiosperms to escape to the treetops into many more ecological niches.
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