165-million-year-old fossil from China reveals mammal ancestor that swam and swallowed like mammals

A 165-million-year-old fossil discovered in China has been identified as a mammal ancestor that could swim and swallow like modern mammals. Named Megacauda sungei, the Jurassic-era animal had a broad tail for swimming and throat bones similar to those of modern mammals. The findings, published in Nature, provide new insights into the evolution of early mammals' feeding abilities.