The study was financed by Suriname Aluminum Company LLC and BHP Bniton Maatschappij Suriname. Suriname Aluminum, which has a government concession to explore gold in the area, will include the data in its environmental assessment study, said Haydi Berrenstein, a Conservation International ofIicial in Suriname, which borders Brazil, Guyana and French Guiana. About 80 per cent of Suriname is covered with dense rainforest.

Thousands of Brazilians and Surinamese are believed to work in illegal gold mining, creating mercury pollution that has threatened the health of Amerindians and Maroons in Suriname's interior.

This discovery is surprising because no previous theories of how the frogs arrived had predicted a single origin for Caribbean terrestrial frogs and because groups of close relatives rarely dominate the fauna of an entire continent or major geographic region," said biology Professor Blair Hedges, who directed the research.

The field work for the study required nearly three decades and some species included in the study are now believed extinct because of habitat degradation and possibly other causes, such as climate change.