CT Scan (IMAGE) University of Chicago Medical Center Caption This is a CT scan of Tiktaalik's fin skeleton, showing its dorsal rays (yellow) and ventral rays (cyan). Credit Image: Tom Stewart Usage Restrictions With paper 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.