A new species of salamander has been discovered under rocks in South Korea but scientists said on Wednesday they don't know how it got there.
The lungless salamander, which breathes through moist skin and lays its eggs on land, is typically found in North and South America and has some distant relatives in Italy and Sardinia.
But scientists had never expected to find one in Korea because it split from its aquatic cousins, which are common there, at least 175 million years ago.
"I've discovered and named nearly 50 species of salamanders — more than 10 percent of the total in the world. I've discovered new genera in Guatemala and Costa Rica. But this tops everything I've ever found by a long ways," said David Wake, an expert on amphibians at the University of California, Berkeley.
"It's so utterly unexpected, so completely unexpected."
Wake reported the unusual discovery, after examining the creature, in the science journal Nature, but it was actually found two years ago by Stephen Karsen, a biologist from Illinois who teaches in South Korea.
The discovery means that lungless salamanders from the family Plethodontidae, which were widespread about 60-100 million years ago, had a wider range than scientists had thought.
Karsen found the creature that measures 40 millimeters (1.5 inch) long and has a stripe down its back simply by turning over rocks in a wooded area.
"People have gone on expeditions looking for terrestrial salamanders in places like Kazakhstan and other Central Asian republic," Wake said in a statement.
Scientists didn't look for the creatures in northern China and Korea or Japan because they didn't expect to find them there.
"And so here (in Korea) they show up, and in the most surprising way, when some guy who's a high school teacher from Illinois goes out with his class and says, 'Let's look for salamanders, let's see what we can find when we turn over rocks and logs.'"
The nocturnal creature was named Karsenia koreana but will be commonly known as the Korean crevice salamander and is significantly different from other lungless salamanders. So far they have been found in 16 locations in three South Korean provinces.