More Radiocarbon Dates for Extinct Mammals
Working together, archaeologists, paleontologists, and physicists are providing more and more facts about the great extinction. Archaeologists are supplying artifacts for cultural associations, and animal bones that the paleontologists identify. In radiocarbon laboratories, the physicists are dating the bones and sometimes charcoal from man-made fires. Through the evergrowing list of dates, many early theories are being replaced with factual knowledge. Some of the dates, however, must be taken with a grain of sodium chloride. A single date from a single sample in only one locality is not too trustworthy. The hazards are obvious, yet nevertheless we have a fairly large body of facts. From these, a general impression of the great extinction is beginning to take shape. As anticipated, man and climate are involved in the disappearance of the animals.
As for climate, a period of much warmer temperatures followed the end of the last glaciation. This lasted from about 10,000 to 2,600 years ago. Antevs isolates the time of highest heat—the Altithermal—as about 7,000 to 4,000 years ago.[33] This matches fairly closely the last dates for our extinct mammals. Heat and aridity may have driven the larger animals to the more and more limited watercourses where man himself would concentrate. Paul S. Martin has noted that the first large mammals to disappear were those in Alaska and Mexico, and that they were followed by the animals of the Plains toward what must have been the beginning of the hot and dry Altithermal period. Martin believes that the grazing and browsing mammals found refuge in the savannas of Florida.[34]
Working with more than 100 radiocarbon dates concerned with the great extinction, Jim Hester (no relation of the junior writer) has brought together results published through 1959.[35] He provides the first reasonably clear picture of the sequence and magnitude of lethal events. We see the ancient forms of horse, camel, and bison, as well as the dire wolf and Columbian mammoth, beginning to disappear 8,000 years ago. Bison antiquus lingers later, though Clovis mammoth hunters may have been active in the Southwest at the same time that Folsom bison hunters were busy on the Plains. Hester’s summary shows how concerned man was in the final death of the great mammals. He lists the last dates for 27 of them. Nine—one-third—were found in archaeological sites of early man; some others were dated by charcoal that may have come from fires where he cooked the meat of the great beasts.
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PYGMIES, AUSTRALOIDS, AND NEGROIDS—BEFORE INDIANS?
Let us have all the skeletons out of the closet. —EARNEST A. HOOTON