VIENNA, AUSTRIA—According to a report in Nature, scientists have been looking for evidence of child labor in the archaeological record. Hans Reschreiter of the Natural History Museum of Vienna said that a child-sized leather cap dated to between 1000 and 1300 B.C. and very small mining picks have been found in salt mines in Hallstatt, Austria. This pushes back the known presence of children in the mines by at least 200 years. Reschreiter and his colleagues will test human excrement found in the mine for hormones that younger children would lack for further evidence of their presence in the mines. In France, archaeologist Mélie Le Roy of the Mediterranean Laboratory of Prehistory–UMR 7269 has found three human baby teeth from two children who were younger than ten at the time of death sometime between 2100 and 3500 B.C. The teeth are marked with grooves usually formed by repeatedly using them as tools for holding plant or animal materials while softening them. Small fingerprints from eight through 13-year-olds have been found on more than ten percent the bricks and tiles of a medieval Lithuanian castle by archaeologist Povilas Blaževičius of the National Museum of the Palace of the Grand Dukes of Lithuania in Vilnius. Archaeologist Steven Dorland of the University of Toronto has found child-sized fingernail marks in fifteenth-century pottery fragments in southern Canada. Even their misshapen pots had been fired, he said. “It shows children in those societies had a certain level of social value.” For more on evidence of children in the archaeological record, go to “Childhood Rediscovered.”