Imagine a world when giant sloths, saber-toothed tigers, vampire bats, horses, camels, tapirs, and pachyderms roamed the earth. This may sound like a Hollywood movie set but, in reality, it was Vail, Arizona about 11,000 years ago. Remains and fossilized evidence of each of these species have been found in nearby caves and archaeology digs. Barely one score ago, the La Tetera cave and its palaeontologic secrets were discovered in Colossal Cave Mountain park. Some twenty years prior, a similar discovery was announced on the Kartchner property near Benson, Arizona. Other evidence has been revealed from archeological digs at Cerros Negros (near Silverbell), Davidson Canyon (off SR83), 111 Ranch (near Stafford), Lehner and Murray Springs (east of Sierra Vista), and Billings (Santa Cruz county) all sites within 75 miles of Vail. You can imagine my excitement when I received an email with GPS coordinates of mastodon tracks in a remote area north of Pomerene!
During the late Pleistocene era, proboscidean behemoths (cousins to modern elephants) roamed this area, grazing and browsing grasses and undergrowth. Remains of 12-ton mammoths and 8-ton mastodons have been found in southeastern Arizona along with other prehistoric mammals. Often Clovis spears and tools are found in these archaeological dig sites demonstrating Clovis ingenuity in group hunting, tool making, and food preservation. Among other theories, there is some speculation that the Clovis people hunted mammoths and mastodons to extinction although the last known mastodon died 4,300 years ago on the remote Russian Wrangel Island far from Clovis culture and time.
At the end of the Pleistocene period (2.5 billion to 11,650 years ago) and the beginning of the Holocene era (last glaciation and beginning of modern human), megafauna (big animals) started to suffer. The critters found in our caves and digs are the last evidence we have of that period. To find exposed mastodon tracks seemed like a big deal to me.
With a little 4-wheel drive riparian wayfinding and at the bend of a desert wash, I found a cliff of exposed rock. Under several thick layers of rocky overburden was an escarpment of sedimentary rock protruding into the stream bed. Embedded on this shelf were several dozen footprints of different sizes of a mastodon parade. The footprints are close to each other and some are overlapping. My large hand and size 13 foot easily fit within the diameter of the footprints. It was clear this herd had walked across a muddy flat squishing down the mud, squirting out the excess, and leaving 1” deep impressions in the muck. This would have dried and then been covered with subsequent layers of soil and rock causing fossilization. It was stunning to me to think about how 20-30 feet of overburden could cover this site in such a short time of 10,000 years. In geology, 10,000 years is nothing!
It was dark and quiet when I left. I pondered the sight of a lonely family of mastodons wandering through the high desert – the last of a breed. What would that look like? Did the Clovis see them? Did they have enough of their natural diet? Were they healthy? Did they have enough genetic diversity? Was it over-hunting, climate change, disease, or genetic degradation that led to their demise?
Is this our fate too?