New treefrog species discovered in Andes

Scientists have discovered a new treefrog species, with an extraordinary, enlarged claw-like structure located at the base of the thumb, that live on a remote tabletop mountain in the Andes.

The discovery, described in the journal ZooKeys, was made during a two-week expedition to a Cordillera del Condor, a largely unexplored range in the eastern Andes.

Having conducted analyses of genetic and morphologic data, scientists from the Catholic University of Ecuador concluded that the frog represented a previously unknown species.

"To reach the tabletop, we walked two days along a steep terrain. Then, between sweat and exhaustion, we arrived to the tabletop where we found a dwarf forest," said Alex Achig, one of the field biologists who discovered the new species.

"The rivers had blackwater and the frogs were sitting along them, on branches of brown shrubs similar in colour to the frogs' own. The frogs were difficult to find, because they blended with their background," Achig said.

The frog has enlarged claw-like structure located at the base of the thumb. The function of the feature is unknown, but it could be that it is used either as a defence against predators or as a weapon in fights between competing males.

The species name, Hyloscirtus hillisi, honors Dr. David Hillis, a member of the National Academy of Sciences of the United States of America, who discovered three closely related frog species in the same genus in the 1980s, while conducting a series of field trips to the Andes of southern Ecuador.

Despite being newly described, Hyloscirtus hillisi is already at risk of extinction. It has a small distribution range near a large-scale mining operation carried out by a Chinese company, researchers said.