A Skeleton Clue to Early American Ancestry (image) American Association for the Advancement of Science Share Print E-Mail Caption A broad view of Hoyo Negro, shot from the floor near the south edge, showing the immensity of the chamber and the complexity of the boulder-strewn bottom. One access tunnel can be seen near the ceiling at top left. This photo was taken by the "painting with light" method on a 30 second exposure. Credit Photo by Roberto Chavez Arce Usage Restrictions Please cite the owner of the image when publishing. This image may be freely used by reporters as part of news coverage, with proper attribution. Non-reporters must contact Science for permission. 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.