The 2012 program addressed this vulnerability by establishing what archaeologists sometimes call a “radiocarbon chronological framework” — a network of dates from multiple different types of material distributed throughout the site’s stratigraphic sequence.

This network included dates from plant materials, animal bones, charcoal from hearths, and the coprolites themselves, distributed across multiple different excavation areas and multiple different stratigraphic layers.

When a dense network of dates is consistent with the expected stratigraphic sequence — when older layers consistently produce older dates and younger layers consistently produce younger dates, without anomalies that would indicate mixing — it provides much stronger evidence for the integrity of the stratigraphy than any single date could provide.

And when specific specimens — like the pre-Clovis coprolites — produce dates consistent with the broader network of dates from the same layer, the case that those specimens are genuinely from that layer becomes much more robust.