All around the world amphibians - frogs, toads, salamanders, newts and the like - are facing extinction by a rapidly spreading fungus that's being made even more deadly by pollution and overdevelopment, some of world's top scientists warned in research published Friday. At least 427 species are considered "critically endangered," with at least a third of all amphibians threatened. In the past 25 years, the scientists say, about 122 species have become extinct.

But the fungus, a unique species called Batrachochytrium dendrobatidis, could start taking on a larger role in the increasing extinction because of global warming, which scientists suspect is lowering amphibians' resistance to the disease.

The fungus was discovered in Australia and Panama only eight years ago and since then has spread across Europe and both the Americas, causing skin infections called chytrid disease in every amphibian species it attacks. The death rate from the infections is 100 percent, biologists have found. The disease, they concluded, "causes catastrophic mortality in amphibian populations, and subsequent extinctions."