'Darwin's tortoise' takes her secrets to the grave at the age of 176 By Mark Chipperfield in Sydney (Filed: 24/06/2006) Harriet, a 23st Galapagos tortoise, has died in a Queensland wildlife park at the age of 176, carrying to her grave the mystery of her origins. John Hangar, a senior veterinarian at the Australia Zoo on the Sunshine Coast, said the reptile suffered a heart attack on Thursday. "Harriet sadly died last night after, thankfully, a very short illness," he said. "She had a heart attack and passed away quietly overnight." Harriet made it into the Guinness Book of World...