B Between 2023 and 2025, our team embarked on a series of transformative expeditions to a cave in San Luis Potosí, Mexico, uncovering an incredible array of Ice Age fossils and delving into the cave’s complex geology and history. Over the course of these expeditions, which totaled more than a month of cumulative exploration, we employed cutting-edge technology, collaborated with local experts, and unearthed nearly 800 fossils.

The expeditions began in 2023 with an ambitious plan to map and study the cave’s interior using advanced underwater drones (ROVs). These drones proved invaluable in navigating submerged sections of the cave and identifying previously inaccessible fossil deposits. However, the journey was not without its challenges. During one particularly intense exploration, we nearly lost an ROV when it became lodged in a narrow underwater passage. Thanks to the ingenuity and quick thinking of a local man, Antonio Gonzales, we were able to recover the drone and continue our work. This early setback highlighted the unpredictability of cave exploration and the importance of collaboration with local experts.

In 2024, we returned with enhanced techniques and a renewed focus on studying the cave’s hydrology and its role in fossil preservation. Underwater drones were once again utilized, allowing us to investigate additional flooded chambers within the cave. From there, we turned our attention to a particularly challenging passage known as “Arrastre Lodoso,” or “Muddy Crawl.” These efforts resulted in the discovery of well-preserved remains of megafauna, including glyptodons, the skull of a dire wolf, and other Ice Age species, significantly advancing our understanding of the region’s ancient ecosystems.

The final expedition in 2025 marked the culmination of our efforts, concluding with the remarkable discovery of saber-toothed cat mandibles and several skulls, including that of a short-faced bear. To validate the scientific significance of these findings, we met with Joaquin and Luis, two of Mexico’s foremost paleontologists and anthropologists. Although they expressed excitement and admiration for the breadth of our discoveries, they are reserving their final conclusions pending further analysis and examination of the materials.

As our work in the cave concludes for now, many mysteries remain. Chief among them is the question of how the fossils ended up in the cave. Were they deposited through natural processes such as floods, left by predatory animals storing their kills, or placed there by early humans using the cave’s pit entrance to dispose of remains after butchering? These possibilities, along with the wealth of data provided by the fossils, ensure that the story of this cave is far from over. Our expeditions have provided an incredible foundation for future research, leaving us eager to uncover the answers to these enduring questions.