By Norm Tessman
The creature may have been the last of its kind. Of an ancient lineage, mastodons were on the brink of extinction when one of them died in a shallow watering hole some fifteen miles southwest of today's Prescott. It was about 8,500 B.C., the last major ice age had ended, and the climate was much like that today, although there would soon be a trend toward cooler and damper weather. That much is known; but there are many other questions about the passing of this creature, not the least of which is the cause of its death-and the possibility that it was killed by human hunters.
This spring, a research project coordinated by the Sharlot Hall Museum may help to answer these and other questions. A team of professional paleontologists, anthropologists, and volunteers will reopen and extend the site near the ancient water hole where the mastodon died. They will search for more of its bones and for those of other animals who died on the site, for evidence of who or what killed them, and for clues about the environment of prehistoric Arizona.
The modern part of this story began in 1989, when a woodcutter found an immense but badly splintered leg bone in an arroyo, and brought it to the Museum. Then in October 1994, knowing that the area warranted watching, two Prescott National Forest employees visited the site. They were elated to find huge tusks eroding from the arroyo's wall. Another surprise came when excavation revealed that the creature was an American Mastodon; it had been expected that the tusks were those of a mammoth, which are much more common finds in the West.
Mammoths belonged to the Elephantidae, the family of modern elephants, but differed in having more massive heads and oversized tusks. Relative newcomers, the true elephants evolved during the last one and a half million years. By contrast, the mastodons formed the Mammutidae, a more ancient and now totally extinct family which had inhabited the Americas for some eight to ten million years. If you saw a living mastodon, you would probably think, "Now that is a very short-legged, heavy-bodied, flat-headed, and generally weird-looking elephant!" The high-crowned teeth of the Elephantidae adapted to the wear and tear of chewing large quantities of rough plant material such as grass; mastodons, with lower-crowned and much less rugged teeth, were primarily leaf eaters, and were common in forested eastern environments. In Arizona, over one hundred mammoths have been found, compared to fewer than ten mastodons.
During the three weeks of the 1994, dig, the huge skull and tusks gradually emerged. Finally, a massive timber, burlap, and plaster cast supported the fossil as it was removed to Sharlot Hall Museum. There, volunteers carefully picked away dirt, revealing a badly crushed skull, tusks, and three teeth. Radiocarbon dating of plant material from around the fossil yielded dates ranging from 10,200 to 10,900 years before the present- using more familiar terminology, this beast roamed Arizona about 8,500 B.C. It is the second-to-latest mastodon known in the entire United States, and the most recent recorded west of the Mississippi. It might literally have been the last of its kind in the West.
Virtually all anthropologists would agree that humans had been in North America for at least 2,000 years by the time of the mastodon's death-some would argue for longer, possibly as much as 20,000 years. These presumably earliest Americans hunted a fantastic assemblage of "megafauna" including mammoths, mastodons, tapirs, large and small camels, native horses, and long-horned bison. They are called the "Clovis Culture" for Clovis, New Mexico, where their unique spear points were first identified. Several well-known archaeological "kill sites" in southeastern Arizona have revealed the butchered bones of mammoths with Clovis points embedded in their skeletons.
In fact, scientists led by Dr. Paul S. Martin of the University of Arizona have proposed that the extinction of these animals was caused by human predation. He believes that Clovis people walked across the Bering land bridge from Asia into North America about 12,000 years ago. The land bridge was created when the earth's ice caps expanded, tieing up water as glacial ice and snow, and consequently dropping sea level. Dr. Martin claims the Clovis hunters found North America full of naive animals who had never seen a human, and in the following two thousand years, hunted them to extinction. There are obvious problems with this idea, such as the fact that animals quickly learn that humans are dangerous, not to mention the logistical problems involved in killing elephants with stone-pointed spears.
Nevertheless, the fact remains that several kinds of oversized animals died out at that time; and Clovis spear points have been found among their bones. Also, there is no other obvious cause for their extinction. Glaciers were receding, and climatic change could have been a factor-however, it is hard to imagine a climate so severe as to wipe out large animals in all the varied environments of the United States. Between the coastal swamps of Florida, the pine forests of Michigan, the high grasslands of Montana, and innumerable other varied biomes, some places should have remained habitable. Even in relatively inhospitable Arizona, wild horses, camels, and even elephants could surely find some livable environment today.
Besides the obvious goals of finding the bones of extinct creatures and possible evidence of human hunters, the 1999, excavation will seek more subtle information. For instance, pollen can be identified-often down to plant species. Fossil pollen will be collected to tell more about the flora, and hence the climate, before and after the mastodon's death.
If the upcoming project turns up a Clovis point associated with the mastodon's bones, it will solve an ancient mystery-perhaps it may also reveal other new information about the earliest Americans and the last of the mastodons.
The Museum is seeking partners to fund various aspects of the mastodon project such as mapping, carbon dating, pollen analysis, and supplies. For information, contact Norm Tessman, 445-3122.
Norm Tessman is Senior Curator at the Sharlot Hall Museum.