Reproduction of prehistoric cave paintings of “La Cueva de los Caballos” at the Barranco de Valltorta (Spain), which date to about 7000 BC. The paintings exemplify Levantine rock art and show a hunting scene, involving men with bows and deer. The cover depicts corresponding drawings by Hugo Obermaier (1877-1946) as published in “Las pinturas rupestres del Barranco de Valltorta (Castellón)”, H. Obermaier and P. Wernert (1919), Comisión de Investigaciones Paleontológicas y Prehistóricas, Madrid, p. 107 (image retrieved from Wikipedia); image modified by MIC. The cover is published under the Creative Commons Attribution (CC BY) license.