Animals that were thought to be extinct for hundreds of years may in fact still be alive, according to a new study by Australian scientists. Biologists at the University of Queensland examined more than 180 different extinct species, only to discover that a third of them were still alive.

The study which appeared in the journal "Proceedings of the Royal Society B" claims that conservationists have been overplaying the number of species driven to extinction.

The study also criticized conservationists by saying too much emphasis had been placed on trying to find species that would never be found again. Diana Fisher, one of the authors of the study said it was more likely that species who were thought to be extinct because of habitat loss rather than human interference or disease were the most likely to be rediscovered.

"It's not too late to find a lot of these species somewhere else where they might be persisting," Fisher told Australia's "ABC". "They might not hang on forever if they don't get found and protected."

One example is the okapi, a species known as the forest giraffe, which was thought to be extinct in the wild for more than 50 years. Researchers found the first evidence in half a century of the presence of the okapi in the Congo's Virunga National Park.

The coelacanth is another species that was thought to have been killed off alongside the dinosaurs more than 65 million years. But in 1938, a South American museum curator rediscovered the fish while he was out at sea.