https://www.science.org/doi/10.1126/science.adh5007

Independent age estimates resolve the controversy
of ancient human footprints at White Sands

Abstract
Human footprints at White Sands National Park,
New Mexico, USA, reportedly date to between ~23,000
and 21,000 years ago according to radiocarbon dating
of seeds from the aquatic plant Ruppia cirrhosa.
These ages remain controversial because of potential
old carbon reservoir effects that could compromise
their accuracy. We present new calibrated 14C ages
of terrestrial pollen collected from the same
stratigraphic horizons as those of the Ruppia seeds,
along with optically stimulated luminescence ages
of sediments from within the human footprint–bearing
sequence, to evaluate the veracity of the seed
ages. The results show that the chronologic framework
originally established for the White Sands footprints
is robust and reaffirm that humans were present in
North America during the Last Glacial Maximum.

"To address the controversy regarding the
ages derived fromRuppia seeds, we obtained
radiocarbon ages of terrestrial pollen recovered
from the same stratigraphic intervals as those
of the seeds, as well as optically stimulated
luminescence (OSL) ages of quartz grains from
within the footprint horizon interval, to evaluate
the chronology of WHSA Locality 2. The dating
techniques, the sample types, and the accelerator
mass spectrometry facility involved in
this study are independent of those used by
Bennett et al."

"Arboreal taxa include abundant Pinus (pine) and
some Picea (spruce), Abies (fir), and
Pseudotsuga (Douglas Fir), which indicate
altitudinal lowering of nearby conifer forests
compared with present day and are consistent
with previous findings for the Last Glacial
Maximum. Nonarboreal taxa are dominated
by Artemisia, reflecting a sagebrush steppe
that is not found in the region today."

Primum Sapienti wrote:

> Abstract
> Human footprints at White Sands National Park,
> New Mexico, USA, reportedly date to between ~23,000
> and 21,000 years ago according to radiocarbon dating
> of seeds from the aquatic plant Ruppia cirrhosa.

Plenty younger than other finds. What's the big deal?

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https://jtem.tumblr.com/post/733754887680196608