Smithsonian.com

A female Urspelerpes brucei (Photo courtesy of Bill Peterman).

Georgia is a hotspot for salamanders; about 10 percent of the 560 species found worldwide inhabit the southern state. And now scientists can add one more to the Georgian list: Urspelerpes brucei.

Two graduate students were hunting for another salamander species in the foothills of the Appalachian Mountains when they came across the tiny amphibian. At the time, they knew only that it was not a species known to inhabit the area. Genetic studies revealed that it was different enough from any known species to get its very own genus, the first new genus of salamanders to be found in the United States in 50 years.

The new salamander species, which is described in an article in the Journal of Zoology, has several novel characteristics.

“The genetic data revealed that this was far more unusual than any of us suspected, which is why we described it in its own genus,” says [biologist Carlos] Camp [of Piedmont College in Georgia].

But the amphibian also looks strikingly different to other species.

For a start, it has the smallest body size of any salamander in the US. It is also the only lungless salamander in the US whose males have a different colour and pattern than females, a trait more characteristic of birds.

Males have a pair of distinct dark stripes running down the sides of the body and a yellow back. Females lack stripes and are more muted in colour.

Males also have 15 vertebrae, one less than females. Yet while most species of lungless salamander have male and females of differing sizes, those of Urspelerpes brucei are close to being equal in size.

Uniquely for such a small lungless salamander, Urspelerpes brucei has five toes, whereas most other small species have reduced that number to four.

The behaviour and lifestyle of the salamander remain a mystery.