Nov. 7 (UPI) -- Anthropologists in Mexico have unearthed ancient pits used to trap mammoths. The remains of 14 woolly mammoths were found inside the 15,000-year-old, human-dug pits.
"[The discovery] represents a watershed, a touchstone on what we imagined until now was the interaction of hunter-gatherer bands with these enormous herbivores," Pedro Francisco Sánchez Nava, national coordinator of archeology at Mexico's National Institute of Anthropology and History, said in a news release.
Previously, anthropologists and archaeologists surmised that mammoth hunting mostly happened on accident, or serendipitously. Mammoths, many researchers assumed, were only attacked by humans when hunters happened upon the animals in a compromised position -- a mammoth stuck in a swamp, for example.
The latest discovery suggests, to the contrary, that some of the earliest settlers of the Basin of Mexico used the environment and social organization to systematically hunt woolly mammoths.
The land where the ancient pits and trapped mammoths were found is located in the neighborhood of Tultepec, a few miles north of Mexico City. Researchers spent 10 months excavating a total 824 mammoth bones at the dig site, dubbed Tultepec II.
The dig site was slated to become a garbage dump, but the discovery put the plans on hold. Some 15,000 years ago, the land was newly exposed -- lake beds that had dried as growing ice caps caused sea levels to decline.
Layers of ash from the eruption of Popocatepetl, 14,700 years ago, were found above and between layers of mammoth bones, which suggests the pits were in use for at least 500 years.
According to Salvador Pulido, director of archaeological excavations at INAH, the Tultepec II discovery could just be the "the tip of the iceberg." Radar surveys of surrounding mammoth grave sites could reveal the presence of similar traps.
"Here we had the opportunity to have profiles of tens of meters, that's why we warned that we were literally in prehistoric traps," Pulido said. "We could argue that in other archaeological salvages we have been in a similar context, but the limits of the excavations only let us see horizontal strata."