Some time prior to World War I, R.C. Niver found the bones of a Jefferson’s ground sloth (Megalonyx jeffersonii) and a bison on his family’s farm located near Norwich Township, Ohio. The bones were unearthed fom 4 feet below the surface of a bog. It’s unknown whether he was attempting to drain the swamp by digging a ditch, ploughing, or deliberately looking for fossils. The bones were examined by the late Oliver Hay, one of the leading paleontologists of the day. Eventually, the ground sloth bones were placed in a box mislabled as mastodon and put in the attic of the obscure Firelands Historical Society Museum where they rested for over 80 years. One day, Matthew Burr was cleaning the attic, and he rediscovered the ground sloth bones. Furthermore, he noticed cut marks on the bone. Although many paleoecologists believe humans overhunted ground sloths into extinction, before Mr. Burr’s astonishing observation, no direct evidence of human exploitation had ever been reported from the archaeological record.
Photo of the bog where researchers think the ground sloth bones were originally discovered.
The ground sloth bones rested in a box labeled as mastodon in the attic of the Firelands Historical Society Museum for many decades.
Brian Redmond, a curator of the Cleveland Museum, examined the bones. He counted 5 chop marks and 41 slice marks on an upper leg bone. (Claws, ribs, an ankle, a knee cap, and the lower leg were the other bones found along with the femur.) Of course, the material was studied thoroughly to discount fraud and other types of morphology such as trampling or river scouring that can produce scratches that resemble anthropogenic marks. They looked at the marks with a scanning electron microscope and confirmed they were made while the bone was fresh, and they learned they were made with 2 different stone tools. The placement of the marks also made sense from a butcher’s point of view. The Indian butcher cut the muscles from the most efficient angles.
There are visible cut marks on this ground sloth femur. It’s a one of a kind specimen. The cracks are the result of drying after the specimen was retrieved from the wet bog.
Though the Ohio ground sloth is the best direct evidence that humans exploited ground sloths, 2 other sites yielded assumed evidence. Scientists found dermal ossicles of a Harlan’s ground sloth at the Kimmswick site in Missouri. Kimmswick is a confirmed mastodon kill site. Dermal ossicles make up the armor that used to help protect ground sloths from predators. Like their cousins, armadilloes and glyptodonts, ground sloth skin was covered in armor, but theirs was covered with thick fur. The scientists who studied the Kimmswick site believe the dermal ossicles came from a sloth hide carried by paleo-Indians to the mastodon kill site. The hide later rotted away but the ossicles endured. The other site is in South America where sloth bones were found associated with human artifacts.
Artist’s rendition of a Jefferson’s ground sloth. They weighed over a ton. The Ohio specimen discussed here was one of the largest individuals ever discovered.
Only 3 Jefferson’s ground sloth bones have ever been found in Ohio. It’s an amazing coincidence that 1 of them showed evidence it was probably killed by humans. The Indians may have been scavenging it, but I doubt it. I’m sure they directly killed it.
13,700 years ago, the Laurentide Glacier had retreated northward from Ohio and Lake Erie was young, and recently filled with glacial meltwater. The climate was rapidly warming but still quite cold during winter. But as I wrote in a previous blog entry, these beasts with neotropical origins could survive cooler climate because they dug deep underground burrows.
It’s sad that these amazing beasts no longer walk the earth. When the paleo-Indians hunted them, they probably never imagined they were in the process of completely wiping them out. They likely had no concept of extinction because they lived in a world of bounty. To them, a ground sloth was an easy feast in a world before grocery stores existed. (Incidentally, in his book How to Get out of the Rat Race and Live on $10 a Month George Leonard Herter claims that tree sloth tastes like pork.) Ground sloths were well adapted to defend themselves against big cats and wolves, but they were helpless against projectile weapons.
“Pre-Clovis Butchered Ground Sloth in Ohio”
The Mammoth Trumpet 28 (1) Jan 2013