Overview
- The study was published in Nature on October 7 and names a new species, Megacauda sungei, from Middle Jurassic deposits in Ningcheng, Inner Mongolia.
- The single specimen is unusually large for a docodont at about 40–52 cm long and roughly 1–2 kg, expanding the known body-size range for early mammaliaforms.
- High-resolution CT scanning and X-ray fluorescence were used to digitally reassemble a slab that had been split for imaging and to reveal preserved pelvis, hind limbs and broad H-shaped tail vertebrae that point to a semi-aquatic, swimming lifestyle.
- Researchers also report rare preservation of hyoid and pharyngeal bones beneath the skull and tiny vertebrate remains in the gut, evidence the animal could chew and swallow prey in ways similar to modern mammals but authors call for bone microstructure and biomechanical tests to confirm function.
- The find adds to growing evidence that docodonts occupied diverse ecological roles and suggests key feeding and infant-care mechanics evolved on the mammal stem lineage, a development that could help explain later dietary expansion in true mammals.