China fossil may reveal first amphibian to live entirely at sea 237m years ago

A recent discovery of the fossil Gerrothorax maritimus reveals that some ancient amphibians lived completely in marine environments. Dated to approximately 237 million years ago, this species had a flattened body covered in bony armour. The fossils were found in deep-sea sediments, indicating they lived far from landmasses. Geochemical tests confirmed the strontium isotopes matched those in seawater during the Late Triassic period.