The animal bones at Hoyo Negro — the gomphotheres, the giant ground sloths, the ancient bears and felines and other megafauna that fell into the pit over the period that the cave was dry — are not merely a backdrop for the human story.

They are, in their own right, significant scientific evidence about the ecology of the Yucatán at the end of the Ice Age and about the human relationship to that ecology.

Gomphotheres were proboscideans — members of the same order as elephants and mammoths — that had evolved in Africa and spread into the Americas before the Pleistocene extinctions.

They were large animals, with trunks and tusks that reflected their evolutionary heritage, adapted to the open woodland and savanna environments of the Pleistocene Americas.

Their presence in the Hoyo Negro pit documents that they were living in or near the Yucatán approximately twelve thousand years ago — a time when the large Pleistocene fauna of the Americas was in the final stages of its extinction event.