Alexandra van der Geer and Frietson Galis, PeerJ (image) PeerJ Share Print E-Mail Caption Authors Alexandra van der Geer (left) and Frietson Galis (right) investigating a vertebra of a woolly rhino. Credit Jacques van Alphen Usage Restrictions Copyright Naturalis. This photograph may freely be used in print and electronic publications about this PeerJ study, provided that proper attribution to the photographers is made. 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.