Overview
- The study, which was published in Nature on July 29, 2026, reports 396 previously undocumented earthworks identified by an airborne LiDAR survey of about 4,497 km² in the Southwest Amazon.
- Authors extrapolate from the sample to estimate roughly 24,000–30,000 similar earthworks regionally and a peak Aquiry population of about 1.25 million to 3 million people, with some upper estimates near 3.8 million.
- The features are large geometric enclosures — circles, squares, rectangles and octagons — built with deep ditches, high embankments and straight roads that likely served as ceremonial, political or communal gathering centers.
- Researchers and outside experts stress key uncertainties in the study, including how sites were counted, how many were occupied at the same time, canopy‑hidden features and the need for ground verification, radiocarbon dating and local Indigenous knowledge to refine the picture.
- If validated by further surveys and fieldwork, the finds would strengthen evidence that precolonial Amazonia was extensively managed by people, with consequences for studies of forest biodiversity, soil formation, climate modeling and contemporary land and heritage policy.