Parent -- <I>G. fortis</I> (IMAGE) Princeton University Caption The bird is a member of the <i>G. fortis</I> species, one of two species that interbred to give rise to the Big Bird lineage. Credit Copyright B.R. Grant Usage Restrictions Copyright B.R. Grant 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.