ATLANTA (AP) - Authorities say a rare tree frog - the last documented member of a species - has died at the Atlanta Botanical Garden.

The Atlanta Journal-Constitution reports ( that the dead Rabbs' fringe-limbed tree frog was recently found dead in its enclosure during a routine daily inspection.

Workers at the garden had nicknamed the amphibian "Toughie." It was estimated to be about 12 years old when it died.

Scientists estimate that one-third to one-half of amphibian species worldwide are threatened with extinction.

The Atlanta newspaper reports that many of the animals are threatened due to habitat loss and diseases such as chytridiomycosis, caused by an aquatic fungal pathogen.

Information from: The Atlanta Journal-Constitution,

Copyright 2016 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.