The first mammoth emerged on 5 November. Then another. And another. Within weeks, the six archaeologists who had been called in had swelled to 56, supervising more than 400 construction workers. Excavators paused whenever bone fragments surfaced. To meet construction deadlines, several excavation areas were opened simultaneously across the site. “We were overwhelmed because every day we were finding them—every day, every day, every day,” recalls Rubén Manzanilla López, an archaeologist with the country’s National Institute of Anthropology and History (INAH) who supervised the salvage excavation, which was supported by the Mexican military.
By 2022, Manzanilla López and his team had amassed more than 50,000 Pleistocene bones from just 3700 hectares. Among them are at least 500 mammoths, 200 camels, 70 horses, 15 giant ground sloths, as well as the remains of dire wolves, saber-toothed cats, bison, armadillos, birds, freshwater snails—and one human skeleton. Nicknamed Yotzin (“unique” in Nahuatl), the man may have died during a hunt or been trampled by a mammoth. The scale of the discovery rivals—and in some ways surpasses—California’s California’s La Brea Tar Pits, the most famous ice age fossil site in North America.