Toughie, the world's last Rabbs' fringe-limbed tree frog and a symbol of the extinction crisis, has died at his home in the Atlanta Botanical Garden.The famed frog's age is unknown, but he's at least 12 years old, and likely older, because he was an adult when collected in 2005.Mark Mandica, who worked with Toughie for seven years, says the frog's story isn't entirely unique. “A lot of attention had been paid to him in captivity, so he even has his own Wikipedia page,” Mandica, head of the Amphibian Foundation, notes. “But there are plenty of other species out there that are disappearing, sometimes before we even knew that they were there.”In fact, Toughie's own species (Ecnomiohyla rabborum) wasn't described until 2008,