Salamanders are slick-skinned amphibians whose diets shift as they mature. Some live their entire lives in water, and others spend their adult lives on land. Those inhabiting water eat plankton when young and then various insects and other small arthropods called “clam shrimp” when older.
Researchers know this from examining the stomach contents of modern salamanders. But if today’s salamanders evolved from some amphibian-like ancestor, shouldn’t that ancestor look significantly different from its present-day descendants? And since it could only eat those creatures that lived at that time—creatures that had not yet evolved into today’s life forms—wouldn’t it have had a different diet?
That doesn’t seem to be the case with two newly described fossil salamanders from China.