Dinoflagellate Cyst (IMAGE) Goethe University Frankfurt Caption This is a characteristic dinoflagellate cyst about 50 micrometers found in sediments dating back to the early Oligocene (33 million years ago). Credit Courtesy of Alexander Houben 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.