The majority of prehistoric cave paintings were figurative and 99 percent of these were of animals. At first, Stone Age artists painted predator animals (lions, rhinoceroses, sabre-toothed felines, bears) almost as often as game animals like bison and reindeer, but from the Solutrean era onwards imagery was dominated by game animals. Pictures of humans were an exceptionally rare occurrence, and were usually highly stylized and far less naturalistic than the animal figures. Abstract imagery (signs, symbols and other geometric markings) was also common, and actually comprises the oldest type of Paleolithic art found in caves of the Late Stone Age, as shown by recent dating results on paintings at El Castillo and Altamira. In addition to figure painting and abstract imagery, prehistoric caves are also heavily decorated with painted hand stencils rock art, most of which - according to recent research by Dean Snow of Pennsylvania State University - were made by females, but men and children were also involved. Some of the best examples of this form of painting are the Gargas Cave Hand Stencils (Haute-Garonne), the Panel of Hand Stencils at Chauvet (Ardeche), and the prints throughout the Cueva de las Manos (Cave of the Hands) in Argentina.