The last known member of a rare tree frog species has died at the Atlanta Botanical Garden in Georgia. The Rabbs’ fringe-limbed tree frog was known to staff at the Garden as “Toughie” and believed to be approximately 12 years old. His body was found in his enclosure last week during a routine daily inspection, the Atlanta Journal-Constitution reported.

Scientists have estimated that up to half of all the world’s amphibian species are threatened with extinction, many of them due to chytridiomycosis, a disease caused by a virulent fungus. The Garden, Zoo Atlanta and Southern Illinois University sent a team of scientists to Central America in 2005 to collect species before the disease struck the region.

The Rabbs’ tree frog was among the species discovered for the first time on that trip, in Panama. It was named after conservationists George and Mary Rabb by the Zoo’s herpetology curator, Joseph Mendelson. Meanwhile, chytridiomycosis arrived in Panama, where it is thought to have wiped out several species of tree frog, including the Rabbs’.

Toughie mated with a female, but none of their tadpole survived and the female died in captivity. Another male specimen, who was kept at Zoo Atlanta, was euthanised in 2012, leaving Toughie as the sole known representative of his species. In 2014, the Garden captured his call on tape for the first time since he was collected nine years earlier.