'Beautiful Chimaera' (IMAGE) University of Alberta Caption Callichimaera perplexa: the oldest swimming crab from the dinosaur era. Credit Daniel Ocampo R., Vencejo Films Usage Restrictions Use with credit. Embargoed until 2pm EST, 24 April, 2019. 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.