|A ring ditch next to Laguna Granja in the Amazon of northeastern Bolivia.|
Image Courtesy of Heiko Prumers and livescience.com.
Stephanie Pappas, of LiveScience.com, has written an interesting exploratory article
into the recent find of massive earthworks sites through the Bolivian and Brazilian Amazon.
"The earthworks predate this shift [from a savannah to a rainforest], which reveals that the diggers of these ditches created them before the forest moved in around them. They continued to live in the area as it became forested, probably keeping clear regions around their structures, Carson said."