Researchers were wrong about the Hula painted frog — twice.
The frog, once classified as extinct, has survived significant habitat destruction, and new analysis has revealed it is actually a living fossil more closely related to extinct animals of the Oligocene-Pleistocene eras than to the modern genus in which it had been placed.
According to an article published today in Nature Communications, Israel’s Hula painted frog was declared extinct in 1996, after not having been observed in the wild since 1955 despite a number of attempts. But recent observations have found the species alive and well — since 2011, 11 specimens of the frog, both alive and dead, have been found in its native Hula valley, including one adult female and four juveniles.
What’s more, the rediscovered frog is getting a new spot on the family tree. When it was first described in the early 40s, the frog was given the name Discoglossus nigriventer. But new molecular analysis of tissue samples from six of the specimens found since 2011 place the Hula painted frog in a sister group outside the genus Discoglossus.
Further analysis of the frog’s skeleton using scans of four individuals (one from 1955 and the other three from 2011) revealed certain characteristics not otherwise found in the Discoglossus genus and, in fact, exclusive to the genus Latonia, which otherwise became extinct more than 10,000 years ago.
The Hula painted frog differs from other members of Discoglossus in ways even discernible to the naked eye, note the study’s authors. Among other distinctive characteristics, for example, all other frogs in the Discoglossus genus have a white abdomen, but the Hula painted frog has a black abdomen dotted with white warts.
The researchers argue that the Hula painted frog must be reclassified as Latonia nigriventer to reflect its status as the only surviving species in the Latonia genus. Further, the study’s authors call for more aggressive conservation of the living fossil’s only known habitat, a single pond in the Hula Nature Reserve in Israel. Much of the reserve has been drained and its swamp habitat destroyed since the frog was first described more than 60 years ago.
Although the Hula painted frog has shown impressive survival skills, outliving not only its nearest relatives but also severe habitat destruction, the article’s authors believe reflooding and restoring the reserve’s swampy environs may be the only way to ensure the amphibian doesn’t become extinct — again, this time for real.