Rock Art (IMAGE) Max Planck Institute of Geoanthropology Caption Iron Age rock art near the city of Osh shows the tall, beautiful horses that drove important Silk Road trade. Credit William Taylor Usage Restrictions This image may only be used in the context of reporting on this publication and with appropriate credit information. 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.