More than 10,000 years ago, a woman set out on a journey on the playa from what is now New Mexico, the little child she carried on her hip, down, adjusted, then picked up the child and set off again.
The remnants of this all-too-human moment are preserved in a trackway found in White Sands National Park – the longest late Pleistocene-double human trackway found anywhere in the world. With a length of 1.5 km (1 km), the set of tracks preserves an out-and-back journey taken on a quick clip by a single adult and a child under 2 years of age.
During the journey, the adult ̵
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“It gives us these amazing snapshots in time,” said Sally Reynolds, a paleontologist at Bournemouth University in the UK and senior author of a new paper on the tracks published online before its December publication in the journal. Quaternary scientific reviews.
The track was first discovered in 2017 thanks to National Parks employee David Bustos, who invited a group of scientists – including Reynolds’ husband, Matthew Bennett, a geologist at Bournemouth University – to see the site. Bustos had noticed possible signs of footprints on the flat, dry playa landscape as he patrolled the park, then a national monument.
Excavations revealed fossil footprints just below the loose white plaster sand. These tracks were originally made on wet soil. As the water evaporated, it left the minerals dolomite and calcite, which formed rocky forms of the footprints.
The tracks run north / northwest in a straight line in one direction before disappearing into the dunes. Next to them are the remains of the return-south / southwest return journey, which appear to have been made by the same person judging by the size of the footprints and the stride length.
Along the way, the tracks for adults are sometimes accompanied by the footsteps of a child under 3 years. Going north, the adult tracks are a bit asymmetrical, evocative for a woman holding a child on one hip. At times, the baby’s footprints appear, perhaps during rest breaks, when the adult lays the squeaky little baby down. There are no children’s footprints on that return journey south, suggesting that the trip may have been taken to drop off the child somewhere.
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“Motivation is something we can’t really talk about in the fossil record, but it’s something we want to know,” Reynolds told WordsSideKick.com. Reynolds wondered if the child might be sick and should be taken to another camp where someone could help him or her. Whatever the reason for the trip, it seemed very purposeful: the footprints did not deviate and the walker did not spar. The stride length suggests that the person was walking at about 5.5 feet (1.7 meters) per second, a fast pace. The region was dry, but the journey was close to an old, now vanished lake, and the ground was muddy and slippery.
“We know the journey was faster than normal speed and over terrain that would have been more tiring than normal,” Reynolds said.
Encounters with animals
The journey would have taken the couple through a landscape dominated by predators like gloomy wolves and saber-toothed cats. Fortunately, the woman and the child do not appear to be threatened; instead, they may have scared some of the animals that came across their trackway. After the couple passed north, a set of animal tracks shows that a giant sloth approached their tracks, got up – maybe sniffed the air? – and then mix in a circle before turning away. Man then stepped on these sloth tracks as they returned south. Previous studies in the area suggest that humans hunted giant sloths, perhaps explaining why the sloth footprints reveal signs of nervousness on the part of the animal.
At another point, a mammoth crossed the human northbound path (before the southbound return journey). The mammoth showed no signs of slowing down or stopping, perhaps suggesting that it did not see the recent presence of a human being as a threat.
There was no organic material under or around the footprints that could be analyzed by radiocarbon dating to reveal the age of the track, Reynolds said. Based on the known extinction dates for mammoths and giant sloths, the tracks must be at least 10,000 years old and possibly as old as 13,000 years, she said. She and her colleagues plan next year to publish data on the age of seeds found under other tracks in the park.
What is clear, Reynolds said, is that the playa by the white sand preserves human footprints spanning thousands of years. The region was a hub for human activity in the late Pleistocene, she said, and the footprints left there could help reveal how humans affected animal populations during this period. (Large megafauna such as mammoths and sloths were exterminated shortly after humans arrived on the scene, and there are controversies as to whether human hunting was to blame.) left by children splashing in puddles that gather in animal footprints.
“It’s safe to say that the entire White Sands is just a giant archive of fossil footprints,” Reynolds said.
Originally published on WordsSideKick.com.