Overview
- The study, published Wednesday, October 7, 2026, in Nature, formally names Megacauda sungei as a new docodont mammaliaform from Jurassic deposits in Ningcheng, Inner Mongolia.
- The nearly complete specimen measures roughly 52 centimetres long and is estimated at about 2 kilograms, making it the largest docodont yet described.
- High-resolution CT and X-ray imaging reveal a broad, flattened tail and robust hind limbs together with tiny vertebrate fragments in the stomach, evidence the team interprets as consistent with a semi-aquatic, small-prey hunting lifestyle.
- The fossil preserves hyoid and related throat bones in a mammal-like arrangement, which could have supported swallowing, lapping and possibly suckling behaviors earlier in the mammal stem lineage.
- Authors and outside commentators stress that targeted bone microstructure studies and biomechanical modelling are needed to test the strength of locomotion and feeding claims and to clarify how these features shaped early mammaliaform evolution.