in outline only: W. Davis, "The Origins of Image Making." Current Anthropology. June 1986. vol. 27 no.3.
An alternative view: "where else would art have had its beginnings? On walls? On bone? There were phenomena of more recent history. In their very first appearance, murals and carvings already show the expertise of long tradition, a tradition developed, it would seem certain, on the artist's own skin." O. Vlahos, Body, The Ultimate Symbol. New York, 1979.

as fine: J. Berger, "The Chauvet Cave." In, The Shape of a Pocket. New York, 2001. p.37. "Context, more than nature, form, or practical function, determines the religious significance of material objects." D.B. Dickson, The Dawn of Belief. Tucson, AZ., 1990. pp 99-100.

scream: "Outdoorsman Bill Monroe, a writer for the Portland Oregonian, recounted his experience in an article for the newspaper. Monroe was elk hunting when the stillness of the late afternoon was broken by an eerie sound. 'The deafening screaming, choking, belching moan from the ridge was chilling.” he wrote. “The kind of scream that sends mothers scurrying to find their children. The kind of scream no cougar or bear could ever squeeze from their throat... unless it was their last. Piercing, echoing, guttural; a single, horrible high-pitched-yet-throaty, inhuman, unnatural creation of Steven Spielberg that makes your skin crawl.'" http://paranormal.about.com/library/weekly/aa112999a.htm.