Researchers are still dating the tracks and haven't ruled out that the prints could be much older than 11,000 years. If that estimate holds, however, the landscape at the time included "a lake bed with patches of seasonal water," senior author Matthew Bennett, also from Bournemouth University, told Seeker.
He explained that peat and sediment were probably reactivated by water, promoting creation of the now-preserved tracks.
He said footprints from multiple people of various ages were discovered along the edge of the lake bed, which is now a playa. A small number of the prehistoric individuals went out into the drying lake bed. The tracks that they left behind show that they were barefoot, but today would have fit into men's shoes sized at about 8.5 in US size, 8 in UK.
The humans appear to have been following, and sometimes even stepping into, prints left behind by about 2–3 giant ground sloths. In the absence of human tracks, these animals tend to travel in a straight or curvilinear fashion. Here, the lumbering beasts distantly related to anteaters and armadillos made sharp changes in their direction of travel. These changes correspond to the approaching humans.
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In one track, a line of human toe impressions suggests that the person approached a giant ground sloth on tiptoe while at least one other person was behind the animal.
These, and the other footprints, according the authors suggest a group of people gathered along the edge of the drying lakebed, possibly to keep the sloths out on the flat mud where they could more easily be attacked.
"One hunter stalks the sloth, harassing it so that it turns toward the stalker," Bennett said. "It rises on its hind legs and swings its forelegs around, putting its claws down to steady itself as it swings."
"While the sloth is distracted," he continued, "another hunter approached and tried to land the killing blow. If successful, the sloth would then have been killed or followed as it bled to death. Having the rest of the group as distant observers would mean that others would be on hand to deal with the carcass, if required."