Horse tooth (IMAGE) Florida Museum of Natural History Caption The origin of Assateague's wild horses has remained a mystery for centuries, but new genetic data supports the theory that they descended from Spanish horses marooned on the barrier island. Credit Florida Museum photo by Jeff Gage Usage Restrictions Credit must be given to the creator. License CC BY 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.