New Dating Extends Age of South Dakota Mammoth Site to 160,000 Years

A recent study published in *Quaternary Research* has dramatically revised the age of a remarkable collection of mammoth remains found deep within an ancient sinkhole. The site, long known for its dozens of fossilized skeletons that once drifted into warm springs, was previously believed to date to about 26,000 years ago. New radiometric dating, however, indicates that these ice‑age giants lived and died more than 160,000 years before the present, pushing their existence well into the early Pleistocene.

The researchers employed advanced uranium‑thorium and optically stimulated luminescence techniques to obtain the older dates, cross‑checking the results with sedimentary context and associated fauna. The sinkhole’s unique environment—characterized by a network of subterranean water channels and a stable thermal regime—has preserved the mammoth remains in exceptional condition, allowing for precise isotopic analysis. This finding suggests that the region’s mammoth population survived far longer than previously thought, potentially altering understandings of megafaunal distribution and climatic adaptation during the early Pleistocene.

The implications of this study extend beyond a single fossil site, prompting a re‑examination of other Pleistocene mammoth assemblages in the area. By extending the known temporal range of these animals, scientists can refine models of megafaunal responses to glacial cycles and better assess the ecological dynamics that shaped the continent’s prehistoric landscape.