A poster child for amphibian extinction has turned up alive and bearing a scientific secret in Israel.

The Hula painted frog, once thought extinct, has turned up in Israel very much alive, biologists report.

And the amphibian represents a "living fossil" species as well, a lineage of frogs otherwise thought to have vanished.

"In 1996, this frog was the first amphibian species to be declared by the IUCN (International Union for Conservation of Nature) as extinct," begins the Nature Communications journal report led by Rebecca Biton of the Hebrew University of Israel. Amid increasing concern over loss of amphibian species worldwide, the frog, "became a poignant symbol of extinction for Israel," the study says.

But in October of 2011, a patrol in the Hula valley wetlands turned up a male frog of the species, one of 10 more, male, female and young, spotted since then. However, the frogs seem to only live in one pond in the valley, part of a swamp drained in past decades.

Analysis of the frogs suggest they belong to a line of European frogs that vanished in past Ice Ages. The scientists call for more study of the species to gain insight into what bumped off [wrong, and offensive, phrase] the rest of their kind.

"The survival of this living fossil is a striking example of resilience to severe habitat degradation during the past century by an amphibian, and may imply on [surely: "have implications for" is the correct translation] the future survival of this species," says the study, especially if more of the former swamp in the frog's valley is reflooded.