In the early thirties, archaeologists began to find a peculiar kind of artifact that broadened their conception of the activities of early man in the New World. Anthropologists had always thought of him as merely a hunter. He needed spear points, scrapers, knives, hammerstones to shape these things, and fire-drills to make it possible for him to cook his prey; but that was all. Then milling stones began to appear, and it became clear that early man—at least in some areas—had been a food gatherer and food grinder, as well as a hunter. These stones are very simple slabs with a hollow worn in the surface by round handstones used in grinding seeds and nuts. Such milling stones, or querns, are not seen in the Old World until we approach the Neolithic, or New Stone Age, and the people who developed agriculture and textiles. Milling stones have been found in a village farming site at Jarmo, Iraq, dating about 7,000 years ago.[50] Agriculture did not enter Europe until about 2500 B.C., and milling stones are not found in its caves until after the Magdalenians of the Old Stone Age. The reason for the precipitate outcropping of milling stones in the Americas is not that our early man practiced agriculture. He did not do that, and he did not make polished stone axes until much later. He was merely a food gatherer. Was he also a food grinder because he was an Australoid who brought the habit to America, just as he brought it to Australia? Or, if not, was he another sort of man, who happened to be smart enough to recognize that North America provided him with many tempting grains and seeds to grind, foods that were not so available in the Old World?[51] It seems more than a coincidence that the earliest American milling stones appear in the arid Southwest, where desert plants have more seeds and larger seeds than plants in moister areas.
The first site to provide milling stones was at Whitewater Creek, in Arizona. Byron Cummings had found artifacts and fossils there in 1926. When Gladwin heard of this at an anthropological meeting five years later, he again set Gila Pueblo in motion. Sayles and Emil W. Haury undertook excavation, and Antevs checked the geology of the various sites which they studied in the area of what is now called the Cochise culture.[52] The excavators found milling stones in the same stratum as the fossils of extinct animals. They found no spear points in this oldest level—a sign that food gathering was the dominant economy of the early Cochise.