Dr Margot Kuitems (IMAGE) University of Groningen Caption This is Dr Margot Kuitems (University of Groningen), first author of the paper, is seen here preparing samples at the radiocarbon facility at the Centre of Isotope Research, Groningen (the Netherlands).. Credit Ronald Zijlstra Usage Restrictions Credit must be given to the creator. No derivatives or adaptations of the work are permitted. License CC BY-ND 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.