<P> Works of the Bubalus period span the Sahara, with the finest work, carvings of naturalistically depicted megafauna, concentrated in the central highlands . The Round Head Period is dominated by paintings of strangely shaped human forms, and few animals, suggesting the artists were foragers . These works are largely limited to Tassili n'Ajjer and the Tadrart Acacus . Toward the end of the period, images of domesticated animals, as well as decorative clothing and headdresses appear . Pastoral Period art was more focused on domestic scenes, including herding and dancing . The quality of artwork declined, as figures became more simplified . </P> <P> The Horse Period began in the eastern Sahara and spread west . Depictions from this period include carvings and paintings of horses, chariots, and warriors with metal weapons, although there are also frequent depictions of wildlife such as giraffes . Humans are generally depicted in a stylized way . Some of the chariot art bears resemblance to temple carvings from ancient Egypt . Occasionally, art panels are accompanied by Tifinagh script, still in use by the Berber people and the Tuareg today; however, modern Tuareg are generally unable to read these inscriptions . The final Camel period features carvings and paintings in which camels predominate, but also include humans with swords, and later, guns; the art of this time is relatively crude . </P> <P> Belonging in the Lithic stage, the oldest known art in the Americas is the Vero Beach bone, possibly a mammoth bone, etched with a profile of walking mammoth that dates back to 11,000 BCE . The oldest known painted object in the Americas is the Cooper Bison Skull from 10,900--10,200 BCE . </P> <P> The ancient Olmec "Bird Vessel" and bowl, both ceramic and dating to circa 1000 BC as well as other ceramics were produced in kilns capable of exceeding approximately 900 ° C. The only other prehistoric culture known to have achieved such high temperatures is that of Ancient Egypt . </P>

What was the most important function of art during prehistoric times