Diagram of Kryptodrakon progenitor (image) George Washington University Caption A diagram shows the fragmentary remains of Kryptodrakon progenitor found in the famed "dinosaur death pits" area of the Shishugou Formation in northwest China. Researchers focused on one of the palm bones, which is longer than its more primitive relatives and shows that it is the earliest known pterodactyloid pterosaur. The skeletal outline is Pterodactylus antiquus reprinted with permission from Peter Wellnhofer. Scale bar is 50 mm. Credit Illustration by Brian Andres Usage Restrictions None 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.