The world's oldest sloth celebrated his unofficial 54th birthday at a zoo in Germany -- and has just fathered his 22nd child. Jan, a Linne's two-toed sloth residing at the Krefeld Zoo in Germany, was estimated to be about 6 months old when he was found in the wild in South America on May 1, 1986, making him at least 54 years old. The zoo, where Jan has lived since ...