fossil (IMAGE) Penn State Caption Rafinesquina, seen in this close-up shot, was an ancient genus of brachiopod belonging to order Strophomenida. This order survived two mass extinction events, but the second represented a 'death sentence' from which they were unable to recover diversity, persisting for another hundred million years as a 'dead clade walking' before their eventual extinction. Credit Benjamin Barnes, Penn State Usage Restrictions non commercial use only 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.