Jonas (IMAGE) Duke University Caption Jonas, the world's oldest known dwarf lemur, died this January just months shy of his 30th birthday. Duke researchers are using lemurs like Jonas to study the biology of aging. Credit Photo by David Haring, Duke Lemur Center Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.