<em>Purgatorius unio</em> (IMAGE) Field Museum Caption This is an example of an early therian mammal, Purgatorius unio. Credit © Nobu Tamura Usage Restrictions Please credit the image to Nobu Tamura 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.