One of the most consequential implications of the White Sands dates — and of the pre-Clovis evidence more broadly — is the recognition that the archaeological record of the earliest Americans is probably far more incomplete than previously assumed.

If people were in New Mexico during the Last Glacial Maximum, they were presumably also in many other places.

They would have camped, hunted, processed food, made and abandoned tools, died and been buried or otherwise left their remains behind.

All of that material evidence from 23,000 years ago should, in principle, be findable.

But much of it is not findable, for a fundamental geological reason: the rise in sea level that accompanied the melting of the glaciers submerged enormous areas of what was once dry land.

The continental shelf of North America — the broad, shallow underwater platform that extends from the current coastline into the ocean before dropping off into deep water — was largely dry land during the Last Glacial Maximum.