The team worked systematically across the exposed surfaces, mapping and documenting trackways, identifying individual impressions, and beginning the process of trying to establish what they had found and, crucially, when the footprints had been made.

Dating the footprints directly — dating the actual sediment in which they were pressed — is technically challenging.

The footprints themselves are not organic material; they are impressions in mineral sediment.

What can be dated is the organic material found within the same sediment layers: seeds, plant fragments, organic carbon incorporated into the mud when it was fresh.

If the organic material can be dated reliably, and if it can be shown to be contemporaneous with the sediment that preserves the footprints, then the footprints can be dated indirectly.

The team focused on seeds of Ruppia cirrhosa — the aquatic plant that grew in and around Lake Otero — found within the sediment layers immediately above and below the footprint horizon.