First fully marine amphibian discovered

Paleontologists describe Gerrothorax maritimus from two near‑complete Triassic skeletons and strontium isotope chemistry indicating life on the seafloor about 240 million years ago; the animal had dorsal bony armor and apparently respired/ate through its mouth rather than through permeable skin. The evidence (sedimentary context, isotope ratios, intact limbs) argues it was a living marine bottom‑dweller, not a washed‑in carcass. — This finding forces a rethink of physiological and ecological limits for amphibians and changes narratives about repeated, surprising marine incursions by terrestrial vertebrates across deep time.