Longipteryx Prehistoric Bird of the Cretaceous (image) University of Chicago Share Print E-Mail Caption Longipteryx, an early bird, lived during the early Cretaceous period approximately 120 million years ago. Research at the University of Chicago and the Field Museum shows that the birds during the Cretaceous displayed far less diversity than the astounding variety that exists today. Credit Allison Elaine Johnson Usage Restrictions News organizations may use this image in connection with reports about the research of Jonanthan Mitchell and Peter Makovicky. Share Print E-Mail 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.