People tracking huge sloths thousands of years ago in exactly what is now New Mexico left footprints that confirm people when hunted the giant animals, scientists report April 25 in Science Advances.Giant ground sloths,
which vanished at the end of the last Ice Age around 10,000 years ago, could weigh more than an elephant. With their deadly claws and muscle, the herbivores would have been formidable victim, says David Bustos, a biologist with the National Park Service at White Sands National Monument in New Mexico.In April 2017, researchers came across more than 100 tracks in White Sands. These "ghost tracks"had previously stayed hidden because they can be seen only under the right wetness conditions-- insufficient or excessive water in the soil, and the outlines of the prints were invisible.Tests of sediment revealed the sloth and human
prints were made at the very same time. An analysis of the tracks also suggested the two types were engaging with one another." We're getting a view into the
past, of an interaction in between two species, "says Sally Reynolds, a paleoecologist at Bournemouth University in Poole, England. "This was a moment of action, a moment of drama. "Reynolds, Bustos and their associates reconstructed the chase: Humans stalked a sloth, or numerous sloths, which the hunters surrounded in the open. At 7 locations, a sloth raised up on its hind legs-- towering over the human beings-- to ward off an attack. The chase continued, with the people in hot pursuit.The encounter"wasn't luck or happenstance; it was cold estimation
, "Reynolds states." Our objective was to eliminate them." The path of footprints ends, though, and it's unclear who came out victorious.