A frog named after Charles Darwin has gone extinct because of a deadly amphibian skin disease, scientists reported last week in the journal PLOS One.

Darwin’s frogs were named after the father of evolution, who discovered them in 1834 in Chile during his voyage around the world on the HMS Beagle.

They are notable for having evolved to escape predators by looking like a dead leaf with a pointy nose and for the fact that the males carry their young around inside their vocal sacs.

Researchers think the northern Darwin’s frog, one of two species, which has not been found in the wild since 1980, has been killed off completely by chytridiomycosis, a fungal disease that infects their skin. Numbers of the related southern species have plunged dramatically.

An analysis into the spread of the disease by a team from the Zoological Society of London and Chile’s Universidad Andres Bello found that habitat loss contributed to the decline, but this alone could not explain the animal’s demise.

A Darwin’s frog protects itself by looking like a dead leaf. One of its two species may now be extinct. (Stringer/Chile/Reuters)

“Only a few examples of the ‘extinction by infection’ phenomenon exist,” said Andrew Cunningham, from the society’s Institute of Zoology.

“Although not entirely conclusive, the possibility of chytridiomycosis being associated with the extinction of the northern Darwin’s frog gains further support with this study.”