The Oldest Human Footprints found in research has confirmed that human feet did not first step on what is today the desert of New Mexico until 21,500 years ago. The venerable age of these prehistoric traces in White Sands, New Mexico, was discovered in 2021, much to the amazement and skepticism of onlookers. The contentious finding has now been confirmed by a team that includes some of the same scientists that performed the more thorough dating.
More than ever, it appears plausible that people lived in what is now North America during the Last Glacial Maximum.
The Oldest Human Footprints found in North America
According to geologist Jeff Pigati of the US Geological Survey (USGS), who co-led the new effort, “the immediate reaction in some circles of the archeological community was that the accuracy of our dating was insufficient to make the extraordinary claim that humans were present in North America during the Last Glacial Maximum.”
But this recent study’s specific methodology truly paid off. Based on radiocarbon dating of seeds from an aquatic plant called Ruppia cirrhosa, or spiral ditch grass, which were discovered lodged in the fossilized prints, the original dating, which determined the footprints were dated between 21,000 and 23,000 years old, was conducted on the fossilized footprints.
High up in the Earth’s atmosphere, radioactive carbon, often known as C-14, is created when cosmic rays strike nitrogen. C-14, which is absorbed into plants and animals as they live, gently rains on Earth all the time.
The ratio of C-14 to stable carbon in a sample can be used to calculate the age of that sample because C-14 decays into stable carbon at a known rate.
The watery nature of the plant on which the team based its findings in 2021 raised doubts about the findings. Water can act as a carbon sink, which means that during the course of their lives, plants may absorb dissolved carbon from the water that is older than the carbon that falls from the sky, creating the illusion that the dated plant material is much older than it actually is.
Oldest human footprint found in the world
Even before that conclusion was released, the researchers were checking other potential dates to confirm their findings. “We were confident in our original ages, as well as the strong geologic, hydrologic, and stratigraphic evidence, but we knew that independent chronologic control was critical,” Oldest human footprint found in the world, explains geologist Kathleen Springer of the USGS, who co-led the research. Conifer pollen was found in the same geological strata as the seeds of ditch grass, indicating that it was probably deposited at the same time. Conifers, on the other hand, are terrestrial plants, so any carbon that has been deposited there would have come from the atmosphere and would not have the same margin for error as carbon from aquatic sources. Approximately 75,000 pollen grains were extracted from each of the three samples by the group. Approximately 75,000 pollen grains were extracted from each of the three samples by the group. used radiocarbon dating to determine the age of each sample.
They also used quartz found in the footprint layers for a different method of dating. A dating method called optically stimulated luminescence enables researchers to identify when a mineral sample was last exposed to sunlight.
Both outcomes were completely in line with the preceding discoveries. The quartz’s last exposure to sunlight was about 21,500 years ago, while the conifer pollen dates between 22,600 and 23,400 years ago.
We now have three independent lines of evidence heading in the same direction, which can aid us in understanding the history of human migration and occupation on this ever-changing globe. Add those findings to the ditch grass.
“Our new ages, combined with the strong geologic, hydrologic, and stratigraphic evidence,” claims Springer, “unequivocally support the conclusion that humans were present in North America during the last Glacial Maximum.”