White Sands fossil footprints
The White Sands fossil footprints are a set of fossilized human footprints discovered in 2009 in the White Sands National Park in New Mexico. In 2021 they were radiocarbon carbon dated, based on seeds found in the sediment layers to between 21,000 and 23,000 years ago, making them potentially the oldest record of humans in the Americas. The 61 footprints are located at the shore of an ice age era lake in the Tularosa Basin.
In 2022, skeptics noted that age estimates relied on carbon dating Ruppia cirrhosa seeds, whose parent plants can intake carbon from groundwater, thereby potentially resulting in dates thousands of years too old. A 2023 study that included radiocarbon dating of pollen and optically stimulated luminescence dating of quartz grains within the footprint layers corroborated the dates obtained from the seeds.