The owner of the Indian Trail Caverns tourist site in Wyandot County, Ohio decided to dig through a shallow depression near the cave where on weekends he allows people to visit for a few dollars admission. He hoped to find a passage that led to his cave. Instead, his digging uncovered a former sinkhole trap that had developed when rainwater dissolved through Paleozoic-aged limestone bedrock during the late Pleistocene. The sinkhole cave had since filled with sediment, but his excavation uncovered the bones of the Pleistocene-aged animals that had fallen into the cave. Gregory Macdonald of Cincinnati University took over and supervised the excavation from 1990-1995. After human artifacts were found, Ken Tankersley, an archeologist, became the excavator-in-chief.
Location of Wyandot County, Ohio.
The most common fossils in the cave were those of flat-headed peccaries, an extinct species well adapted to living in arid, sandy grasslands. They lived in herds. At least 43 individuals became trapped in the cave. By contrast, only 1 long-nosed peccary, an animal that likely preferred forest edge, fell in the sinkhole. Fossils of other ungulate species found in the sinkhole include the extinct stag-moose (Cervalces scotti), caribou, and white tail deer. Two species of bear died in the cave–the extinct giant short-faced bear (Arctodus simus) and a black bear. Fossils of some of the species of smaller animals that lived here at the end of the Ice Age were from species that no longer occur this far south: pygmy shrews, yellow-cheeked voles, heather voles, pine martens, and fishers, though the latter may have survived here till the time of European colonization. Red squirrels prefer boreal forests and used to range here as well but presently do not. The extant species of beaver and the extinct giant beaver (Casteroides ohioensis) lived in this area then. Raccoons, striped skunks, weasels, woodchucks, chipmunks, gray squirrels, porcupines, and rabbits are part of the present day fauna that also lived here during the late Pleistocene. Bones of turkey, channel catfish, and bullheads were probably brought into the cave by avian predators. As I noted in an essay last week, I hypothesize bullhead catfish were the most common fish living in southeastern North America during the coldest phases of the Ice Age, and that may have been true in the midwest too.
This bone spear point was found in the sinkhole next to this flat-headed peccary shoulder blade with a hole in it that matches the spear. This is direct evidence that man did hunt peccaries during the Pleistocene–a fact that some archaeologists bizarrely dispute. They dispute it because they want to deny that man is responsible for megafauna extinctions. How much evidence do they need?
Flat-headed peccary bones found in-situ in the sinkhole.
Paleontologists have yet to find the fossils of mammoths, mastodons, horses, bison, elk, helmeted musk-ox, wooly musk-ox, Jefferson’s ground sloth, scimitar-toothed cats (Dinobastis serum), grizzly bears, or snowshoe hares at this site, but these species have been found in other sites in the region and likely occurred in this area but none happened to fall inside the pit. I don’t think saber-tooths (Smilodon fatalis) nor dire wolves ranged this far north. Scimitar-tooths and timber wolves occupied their ecological niches in this region.
Several human artifacts were discovered by paleontologists searching through the vertebrate fossils. A stone arrowhead and scraper were identified as being from a late Clovis culture. Two bone spearpoints were also found, and a hole found in a fossil peccary shoulder blade perfectly matches the spearpoints. One of the points appears as if it had impact damage from striking the bone. Some of the fossil bones are burned–either by humans or in a forest fire. Remains of a butchered snapping turtle suggest humans enjoyed a chelonian snack at this site.
Radio-carbon dating of charcoal indicates calender year dates of 12,600 BP-13,000 BP. Burned bones give ages about 1000 years older than that.
The site of the Sheridan sinkhole trap was under the southern lobe of the Laurentide Ice Sheet during the Last Glacial Maximum. The sinkhole likely formed following the withdrawal of the glacier when an increase in precipitation facilitated the collapse of the underlying limestone bedrock. The region was mostly bare rock, gravel, and loess (rock ground to dust by glacier movement) for a few centuries; and because it was located at the edge of a receding glacier, conditions were windy. The first species of plants to colonize this area were the lichens that could grow on the rocks. Pioneer stands of cedar, aspen, and ash soon took root in the shade-free environment. Thickets of some unknown thorny shrub species probably spouted, providing protection for the herds of flat-headed peccaries, a species capable of enduring the frequent sandstorms stirred by the winds blowing off the nearby glacier. Caribou also survived here, able to eat lichens. After a thousand years or so, grass, spruce, jack and red pines, and even oak colonized the area around the site, creating some forest edge habitat and attracting red squirrels, rabbits, white tail deer, and long-nosed peccary. The cool moist conditions and an abundance of glacial meltwater created bogs and marshes–habitat for beavers, giant beavers, and possibly the stag-moose, if the latter had the same habitat preferences as the extant species of moose. (The stag-moose, despite its name, was not closely related to the modern day moose.) For a few thousand years, boreal forest elements mixed with deciduous flora and fauna, making for an odd environment for which there is no modern analogue. Eventually, as the climate warmed, broadleaf trees became dominant in this region, and sediment filled the sinkhole so that it no longer acted as a trap…and a window to the ecology of the past.
“Indian Trail Cavern–A Window of Ohio’s Pleistocene Past”
Ohio Geology Spring 1992
The Early Settlement of North America
Cambridge University Press 2002