A 237-million-year-old fossil of Gerrothorax maritimus reveals amphibians may have lived in marine environments, challenging previous beliefs.
Amphibian fossil found in China
A 237-million-year-old fossil discovered in Guanling National Park in southwest China has raised new questions about the ability of ancient amphibians to live in marine environments. The fossil belongs to a species named Gerrothorax maritimus, which was found by local farmers and is now considered the first evidence that some amphibians may have adapted to life in the sea.Amphibian’s unique features
The fossil is 74 centimeters long and shows features typical of primitive amphibians, including four legs and gills. However, unlike modern amphibians, there is no evidence that G. maritimus underwent metamorphosis, a process that transforms tadpoles into adult forms like frogs.Marine environment confirmed
Researchers used strontium isotope analysis on the fossilized bones to determine that the animal reached adulthood in a marine environment. This finding was supported by the fossil's location, which was 30 kilometers from the coast and near a large marine ichthyosaur fossil.Expert reaction to the discovery
John Long, a paleontologist at Flinders University in Australia, called the discovery unprecedented, noting that no modern amphibian species is fully adapted to marine life. The fossil's solid body armor, which originally protected it from predators in freshwater, also allowed it to survive in the sea.
