Harriet the tortoise turns 175

"One of the world's oldest living animals, Harriet the tortoise, celebrated her 175th birthday on Tuesday -- with a pink hibiscus flower cake at her retirement home in northern Australia.

Australia Zoo, where Harriet has spent the past 17 years, says the Giant Galapagos Land Tortoise was collected by scientist Charles Darwin in 1835, although some historians have disputed this.

There is no doubt however over the age of Harriet -- who for more than a century was thought to be a male and named Harry -- and she is recognised by Guinness World Records as the world's oldest living chelonian, or reptile with a shell of bony plates.

"She would definitely be the oldest living animal on Earth ... I can't see why she shouldn't live till 200," Australian conservationist and television celebrity Steve Irwin, who owns Australia Zoo north of the city of Brisbane, told Guinness World Records."