The Discovery
Researchers from the University of California, Davis, Peking University, and the Geological Museum of Guizhou analyzed two well-preserved fossil skeletons discovered in southern China’s Guizhou Province. Found in deep-sea sediments located hundreds of miles from any large landmass, the remains belong to a newly described species named Gerrothorax maritimus. Living nearly 237 million years ago during the Late Triassic period, this spiky, toothy creature represents the first fully marine amphibian ever identified in the fossil record.
What Scientists Found
The fossils revealed an animal roughly three feet long with a flattened, disc-shaped, and chunky body. Unlike modern giant salamanders which are elongated, Gerrothorax maritimus possessed a dense layer of bony armor. Scientists determined that it was a bottom-dwelling suction feeder that waited on the seafloor to draw in prey, similar to modern wobbegong carpet sharks. Its bony armor likely protected it from massive ocean predators, including 10-foot-long ichthyosaurs. Because the fossilized skeletons were nearly complete and still possessed their fingers, researchers concluded the animals died close to where they lived in the ocean rather than washing out from land.
Why It Matters
Out of more than 8,000 living amphibian species, none reside entirely in saltwater environments, and less than two percent have any degree of salt tolerance. Modern amphibians rely on permeable skin to absorb water and breathe, making them highly vulnerable to saltwater. The discovery of Gerrothorax maritimus shows how an ancient amphibian adapted to overcome this limitation. Its bony armor prevented its skin from absorbing ocean water, forcing the animal to drink saltwater through its mouth and digest it internally. It then used its gills to filter out the excess salt, allowing it to spend its entire life in a marine ecosystem.
Source: prehistoric animals new study - BingNews · Published October 26, 2026 · Photo by Buddy AN on Unsplash