A 161 million-year-old fossil, linked to a line of extinct frog-like amphibians, is the oldest tadpole ever found. By Asher Elbein The metamorphosis of a frog from baby to adult is one of nature’s ...

This image shows a frog tadpole with normal blood vessel development (fluorescing, top) and a frog tadpole with blood vessel development that was disrupted by the common antifungal medication, ...