But two months ago, a doctoral student at James Cook University in Townsville conducting research on another frog species in Queensland stumbled across what appeared to be several Armoured Mistfrogs in a creek, said professor Ross Alford, head of a research team on threatened frogs at the university.
Conrad Hoskin, a researcher at The Australian National University in Canberra who has been studying the evolutionary biology of north Queensland frogs for the past 10 years, conducted DNA tests on tissue samples from the frogs and determined they were the elusive Armoured Mistfrog.
Alford's group got the results on Wednesday. A spokeswoman for the Queensland Environmental Protection Agency also confirmed Hoskin's findings.
"A lot of us were starting to believe it had gone extinct, so to discover it now is amazing," Hoskin said. "It means some of the other species that are missing could potentially just be hidden away along some of the streams up there."
Craig Franklin, a zoology professor at The University of Queensland who studies frogs, said the Mistfrog's rediscovery was exciting.
"It's very significant," Franklin said. "We've lost so many frog species in Australia ... Hopefully it's a population that's making a comeback."
The light brown frogs, with dark brown spots, congregate in areas with fast-flowing water. So far, between 30 and 40 have been found.
The chytrid fungus was blamed for decimating frog populations worldwide, including seven species in Queensland's tropics between the late 1980s and early 1990s.
Armoured Mistfrogs had been classified as critically endangered rather than extinct, but most researchers believed they had died out from the disease, Alford said.
Most of the Armoured Mistfrogs that Alford's group has found are infected with the fungus, but the disease does not appear to be making them sick, he said.
Alford and his team plan to study the creatures to try and determine how they managed to coexist with the fungus, in a bid to aid future conservation and management of vulnerable frogs.
On the Net:
James Cook University: http://www.jcu.edu.au/
The Australian National University: http://www.anu.edu.au/index.php