Megacauda sungei fossil discovery reveals Jurassic semi-aquatic mammal

Researchers have discovered a 165-million-year-old fossil of Megacauda sungei in Inner Mongolia, China, identifying it as the oldest known semi-aquatic mammal. The creature, which lived during the Jurassic period alongside dinosaurs, measured approximately 50 cm in length and weighed between 1 and 2 kg.

According to findings published in the journal Nature, the animal possessed a beaver-like tail and a lifestyle similar to a platypus or otter, hunting small vertebrates such as fish and salamanders. The exceptionally well-preserved fossil includes impressions of skin and fur.

A significant aspect of the discovery is the animal's throat anatomy. The fossil reveals a musculoskeletal structure in the throat similar to modern mammals, including humans. This allows for the consumption of chewed food in small pieces rather than swallowing large portions whole, and enables offspring to nurse. This anatomical feature allowed the creature to breathe and feed simultaneously.