9 Torvosaurus tanneri, Extinct Since the Jurassic

Major extinction events have occurred periodically throughout Earth history, five all total, but did you know, that we are presently in the midst of one right now. Those in the past seem to have developed over millions of years but the present one is especially troubling in that it is happening so fast; also because we humans are the causative agent.

Human caused extinctions are nothing new. For sometime now a hotly contested debate among professionals has centered around two theories that attempt to explain the disappearance of North America’s large mammals: The first is climate change. At the end of the last Ice Age, continent size savannas gave way to steppe conditions destroying habitat for grazers as well as dependent predators. The second is the arrival of the first Americans. It has been proposed that these Paleo-Indians entered America with their Cloves Point technology, sufficiently lethal to decimate the large animals which had evolved with little or no fear from man. Since both events occurred at about the same time, these two theories probably combined to deliver a one-two punch from which the animals could not recover. The result was that America was changed from a Pleistocene Serengeti to the depressed conditions we find today, 73% of large mammal genera gone from North America and a staggering 80% extinction in South America.

The Paleo-Indians had to have played a roll in this great natural history drama since the time coincidence is so exact. The Clovis People, in particular, must receive much of the blame. The Clovis Point is large, razor sharp, and when attached to a shaft and thrown with an atlatl, it supplies the fire-power necessary to accomplish the deed. Food was the motive. As well-known naturalist E.O. Wilson tells us: "The remains of mammoths, bison, and other large mammals exist in association with human bones, charcoal from fires, and stone weapons of the Clovis Culture. These earliest Americans were skilled big-game hunters, and they encountered animals totally unprepared by evolutionary experience for predators of this kind…..It seems likely that the Clovis people spread through the New World and demolished most of the large mammals during a hunter blitzkrieg spanning several centuries."

Following on the heels of the Clovis, came the Folsom Culture. Folsom Points have also been found at North American kill-sites. For a few hundred years, perhaps a bit more, the pressure on the native fauna was relentless. Among the losers were the American elephants, horses, camels, lions, short-faced bear, the saber-toothed cats, large-horned bison, ground sloth, and just about everything else that made a large target.

We can admire the skill and persistence of those Early Americans. We should, but what a loss it was to Earth’s biodiversity – an entire ecosystem left in ruin with no hope to ever be revived. However, before we become critical, we need to realize that the greatest extinction event of all time is occurring right now and without doubt, we are the ones responsible. Estimates, (E.O. Wilson’s numbers) are that as many as 2,000 species of mammals, birds, and reptiles are beyond recovery and at the verge of extinction right now. Among all species, about 5 go extinct every day; nearly all of this is due to human activity, mostly a result of habitat loss. Like it or not, we are the World’s stewards and apparently we have not done very well. It has been said that history repeats; how true that is and how sobering to contemplate.