165-Million-Year-Old Fossil Reveals Earliest Mammal-Like Suckling and Swallowing

A new genus and species of docodont, identified as Megacauda sungei, has been discovered in Inner Mongolia, China, dating back approximately 165 million years. The findings, published in Nature on October 7, include digital reconstructions that depict a contemporary throat structure featuring bony projections and hyoid bones, enabling suckling without the risk of liquid entering the nasal passages. Found nearly ten years ago, this creature is recognized as the earliest known semi-aquatic mammal-like animal, measuring between 16 and 20 inches in length and weighing between 2 and 4.5 pounds. The genus name highlights its broad tail, while the species is named in honor of paleontologist Sun Ge. Zhe-Xi Luo and Thomas Martin co-authored the study, with insights from experts Jessica Theodor, Sue Hand, and Oliver Griffith.