Neither elephant nor sloth, neither horse nor camel, is such a common companion of the points of Folsom man as is an extinct form of bison. It was larger than the historic animal, and had longer and straighter horns. Though it is known variously as Bison taylori, Bison antiquus antiquus, and Bison antiquus figgensi, it was probably of a single type, the last named. Now one of the significant things about Folsom is that the point never turns up with the modern variety of buffalo which goes by the interesting name of Bison bison,[17] or even Bison bison bison—unless, of course, lack of skull material has led scientists astray. Therefore, if we seek the latest date of Folsom, it would seem as if we must seek the death day of the extinct bison.
Prehistoric and modern bison. Above, at the left, is an outline of typical horn cones of Bison antiquus antiquus, whose bones have been found with Folsom points. Its horns were longer and straighter than those of the buffalo of today, Bison bison, shown at the right. Below is a still larger and more ancient type, Bison latifrons, with an eighty-inch span.
Protagonists of early man have argued that Folsom must date far, far back, or there would not be time for the evolution of the modern bison of the High Plains. Lately, however, Eiseley has developed a theory which does away with the long period of evolution from Bison antiquus into Bison bison, and yet pins down Folsom to the end of the glaciers. There is some evidence that the kind of bison Folsom man hunted migrated up into Canada when the glaciers melted, and that the “modern” variety, which we call “buffalo,” came up from the south and took over the High Plains. As the temperature moderated over the whole northern hemisphere the plains of Canada began to resemble the plains of the United States, where the prey of Folsom man had flourished. The climate and the vegetation of the High Plains, moving north behind the ice, took Bison antiquus along. The same northward movement of climate and vegetation occurred from Mexico to the High Plains, and it carried to their historic habitat the buffalo that have left their bones in old soils south of the border. The only place where we meet the two varieties of bison together is a peat bog in Minnesota.[18]
The evidence that Bison antiquus moved to Canada is not complete, but it is suggestive. There are accounts of bison horns from Athabasca “nearly twice the length of the Plains’ ones and much straighter.”[19] Ernest Thompson Seton provides the same kind of evidence.[20] The Canadian bison and the Folsom variety seem “suspiciously similar,” says Eiseley. Unfortunately, in 1925, before the bison of Athabasca—the second surviving race, Bison bison athabascæ—had been properly measured and observed, Bison bison from the High Plains were brought north to breed with the Canadian variety. Eiseley feels it is a possibility that the Athabascan animals “represented, at least in a mixed form, the last of the Ice Age bison which early man had hunted in the western plains.”[21] If this is true, it means that Folsom man was fully developed in the period before the melting of the glaciers drove his favorite game north to Canada. It means, further, that he or his immediate forebears may have entered the plains 50,000 years ago when a corridor opened through the western ice fields. (See illustration, [page 26].)
The Folsom bison may also have gone northeast to the edge of New England. Grasslands extend from the High Plains of the classic Folsom point northeast to Illinois and Indiana, and ancient steppes once ran through Ohio to New York State and probably to New Jersey and southern New England.[22] Antevs suggests that late bands of Folsom men pursued their bison across this area. Certainly they left their cruder form of point in this part of the Middle West and the East.[23] But where, in this area, are the fossils of the extinct bison?
The Mystery of Extinction
A hundred years ago the French scientist Cuvier, who gave much time to the study of the fossils of extinct mammals, presented the “cataclysmal” explanation of their end. They were destroyed by sudden great geologic changes. To us, perhaps, these changes seem to have ignored certain other animals in a most disquieting way. Cuvier was at a disadvantage, of course, for he was working in a Bible-ridden world which had to accept the Book of Genesis as fact. Even as late as 1887, Henry H. Howorth wrote in The Mammoth and the Flood:
These facts ... prove in the first place that a great catastrophe or cataclysm occurred at the close of the Mammoth period, by which that animal, with its companions, were overwhelmed over a very large part of the earth’s surface. Secondly, this cataclysm involved a very wide-spread flood of water, which not only killed the animals but also buried them under continuous beds of loam or gravel. Thirdly, that the same catastrophe was accompanied by a very great and sudden change of climate in Siberia, by which the animals which had previously lived in fairly temperate conditions were frozen in their flesh underground and have remained frozen ever since.[24]
In the hundred years since Koch found a mammoth and a spear point in Missouri we have learned little that is definite about the reasons for the extinction of mammoth, mastodon, camel, horse, sloth, and the rest. We merely know that they died out as the glaciers began to melt. The most natural guess for either scientist or amateur is that change of climate was the lethal factor. Yet we know that many of them had already survived drastic changes of climate and lived through interglacials as well as glacials in the Great Ice Age. Further, how do we account for the survival of deer, antelope, fox, rabbit, moose, beaver, bear, and so many other animals? How could climate be so selective? If the dire wolf died, why not the timber wolf? If the short-faced bear, why not the grizzly? If one form of rabbit and three forms of antelope, why not all rabbits and all antelopes? If disease instead of climate was the great eliminator—as some have suggested—we face the same dilemma.