Massive ground sloths, distant relatives of the sloths that live on Earth today, roamed North America once upon a time. At the White Sands National Monument in New Mexico, researchers discovered evidence of giant sloths that were once hunted by early man. The White Sands desert fossils reveal how humans tracked and hunted these giant prehistoric creatures and offer insight into these mysterious mammals. When it comes to the ancient giant sloth, facts are limited, but what paleontologists have found may make you rethink how you look at the cuddly-looking, slow-moving sloths of today.
In a rare discovery of human footprints, paleontologists have discerned how our ancestors tracked giant sloths, called Megatherium and Megalonyx, through the White Sands desert. The unique information these prints provide gives remarkable insights into predator-prey interactions during the Pleistocene Epoch.
Human footprints are not likely to remain preserved over long periods of time but because these individuals walked within the larger prints left by the giant ground sloths they were hunting, over 25 prints were were preserved in fossil material. When humans were tracking, harassing, or hunting giant sloths, they appeared to have done so stealthily, staying in the exact same tracks as the large mammals they trailed.
Based on the layout of the giant sloth and human footprints, it appears as though there was teamwork involved in the exercise. Researchers theorize that a face-to-face match with a giant sloth was best won by incorporating an element of surprise. Dr. Matthew Bennett speculates, “While [the sloth] was being distracted and turning, somebody else would come across and try and deliver the killer blow. It’s an interesting story, and it’s all written in the footprints.”
There's evidence that sloths moved in zig-zag patterns, indicating evasion tactics. It's difficult to tell if humans pursued more than one sloth at a time, however.
In addition to the footprints of the giant sloths and humans, there are track marks that indicate the sloths walked bent over, dragging their knuckles along the ground. When they were under threat, however, they stood erect. According to the layout of the sloth prints, the mammals turned to face their hunter, standing tall on their hind legs. Moving their arms in what researchers call "flailing circles," giant sloths used their front limbs to protect themselves.
The "elongated kidney-shaped tracks and claw marks" left by giant sloths reveal how strong and lethal their limbs could be. Like modern sloths, although much larger, the giant sloths had blunt faces, strong jaws, large teeth, and three claws on their forelimbs. Their long arms and sharp claws gave them a deadly reach when confronted.