Fossil discovery in China reveals 165-million-year-old suckling mechanism

Researchers have uncovered fossil evidence indicating that the ability to suckle and consume milk dates back at least 165 million years. The discovery centers on Megacauda sungei, a small, swimming, salamander-eating animal from the middle Jurassic found in Inner Mongolia, China.

An international team, including scientists from the University of Chicago and the University of Bonn, used CT scans to analyze the fossil. The specimen is notable for the preservation of delicate structures, specifically the tiny hyoid bones that anchor the tongue and throat muscles, as well as the roof of the mouth. These structures are essential for the complex coordination required to suckle without choking.

The findings, published in Nature, suggest that by the Jurassic period, mammal relatives had already developed advanced feeding skills, such as chewing and nursing. These biological advantages likely allowed these early ancestors to thrive and diversify in environments dominated by dinosaurs.