Green Darner Dragonfly (image) Marine Biological Laboratory Caption This is the green darner dragonfly, a member of the Aeshnidae family, in which Robert Olberg of Union College originally discovered the target-selective descending neurons (TSDNs). Credit Credit: Brian Robert Marshall/Wikimedia Usage Restrictions Please use with proper credit. 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.