Thought-to-be-extinct frog found to be ‘living fossil’

This week the remarkable story of a one of the rarest frog in the world got even more incredible. Thought to be extinct, but rediscovered two years ago, the hula painted frog has now been declared a ‘living fossil’.

The elusive hula painted frog now turns out be a ‘living fossil’. Photo: Frank Glaw.

Last year, as part of our amphibian special feature the BioFresh blog reported on a campaign called the ‘Search for the Lost Frogs‘, which aims to find 100 species of frogs and other amphibian species that have been deemed ‘lost’. The hula painted frog was among them, and when it was rediscovered in 2011 it was one of the most highly prized finds of the whole campaign.

The frog, which has a distinctive dark belly with white spots, had only been seen 3 times and the last time had been nearly 60 years ago in 1955. Scientists had feared the worst for the species when it’s only known habitat, the Lake Hula marshes in Israel, was drained in the 1950’s. But, during a routine patrol in 2011, the frog hopped back into existence into the path of a stunned park ranger. There have since been another 10 sightings.

Now, scientists have added another layer to the story of this elusive amphibian: it is a ‘living fossil’. A living fossil is a term given to a species that has largely stayed the same over millions of years and that has few or no living relatives. This frog hasn’t just survived, hidden for 60 years in a swampy marsh in Israel. It has survived 15,000 years longer than its closest relative! The hula painted frog was originally thought to be a member of the genus Discoglossus. Scientists have now realised that the Hula painted frog is actually a member of the genus Latonia, previously only known through the fossil record and once widespread throughout Europe.

Female Hula painted frog (top left) and the typical habitat in the Hula reserve. Photo: Biten et al.

The revelation was made after scientists at Israel’s Ruppin Academic Centre performed DNA tests on tissue samples of the frog and the findings were published in the journal Nature Communications. “Nobody ever had a chance to see a Latonia because it went extinct in Europe. The only way anyone could see it was through looking at fossils,” said Professor Sarig Gafny, co-author of the study. “But then with every characteristic that you look at in the current Hula painted frogs, it matches that of the fossils of Latonia and not that of the Discoglossus… So this is a living fossil.”

Other amazing amphibians that have been rediscovered are the Rio Pescado stubfoot toad, the Chalazodes bubble-nest frog, last seen in 1874 and the Silent Valley tropical frog, which was incredibly found sitting in the bottom of a rubbish bin!

While this is a huge win for conservation, there are still over 200 species of amphibians that remain ‘lost’, perhaps forever. Amphibians the world over are facing an extinction crisis with the main threats coming from habitat loss, climate change and a deadly fungal disease. The rediscovery of the hula painted frog is a reminder not only of the resilience of nature, but also of what we stand to lose. It is at once a sign of hope, and a call to further action.