First fossil evidence of marine amphibian stuns paleontologists: Very unusual

Was it a sea-lamander?Scientists have discovered the first-ever fossil evidence of sea-dwelling amphibians, potentially upending everything we know about the animal class.“It’s a sort of very unusual member of the lineage,” co-author and paleontologist Ryosuke Motani, of the University of California, Davis, said in a statement.Dubbed Gerrothorax maritimus, the amphibian in question was a three-foot-long, chonky critter that resided on the bottom of the ocean, per the study in Nature Ecology and Evolution.This theory stemmed from an analysis of two nearly complete, 237-million year-old skeletons that were unearthed in a region of China once covered in ocean.During this period in the Late Triassic, this aquatic ecosystem was inhabited by turtles, icthyosaurs and other species of marine reptiles.Nonetheless, the ocean denizen was an anomaly as none of the 8,000 species of modern amphibians are known to reside in salt water.

Meanwhile, fewer than 2% can tolerate salinity on account of their porous skin, which is essential for gas and water exchange, Science Alert reported.There had also been no recorded evidence of a prehistoric, seafaring amphibian — until now.As the specimens in question were located nearly 19 miles from the closest islands, researchers theorized that the ancient amphibians spent their entire lives at sea.This would make them an extreme outlier in the amphibian class, which is defined by the ability to navigate both land and water.How does a typically freshwater-reliant creature survive in a marine environment? The researchers cited the amphibian’s bony carapace, which, along with protecting them against predators like ichthyosaurs, prevented maritimus from absorbing saltwater through its skin.Instead, this oceanic salamander drank the water through its mouth and filtered it with its digestive system, posited the researchers, who suspected that the gills would’ve helped maritimus sift out the salt.The amphibian’s formidable armor and s...