Scientists have discovered more than 1,000 species in Southeast Asia's Greater Mekong region in the past decade, including a spider as big as a dinner plate, the World Wildlife Fund said Monday.
A rat thought to have become extinct 11 million years ago and a cyanide-laced, shocking pink millipede were among creatures found in what the group called a "biological treasure trove".
The species were all found in the rainforests and wetlands along the Mekong River, which flows through Cambodia, Laos, Myanmar, Thailand, Vietnam and the southern Chinese province of Yunnan.
"It doesn't get any better than this," Stuart Chapman, director of WWF's Greater Mekong Programme, was quoted as saying in a statement by the group.
"We thought discoveries of this scale were confined to the history books."
The WWF report, "First Contact in the Greater Mekong", said that "between 1997 and 2007, at least 1,068 have been officially described by science as being newly discovered species."
These included the world's largest huntsman spider, with a leg span of 30 centimetres (11.8 inches), and the "startlingly" coloured "dragon millipede", which produces the deadly compound cyanide.