Dickinsonia Fossil (IMAGE) Australian National University Caption Scientists from The Australian National University have discovered the have discovered that 558 million-year-old Dickinsonia fossils do not reveal all of the features of the earliest known animals, which potentially had mouths and guts. Credit Ilya Bobrovskiy, The Australian National University (ANU) 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.