Millions of lasers shot from a helicopter flying over the Amazon basin have revealed evidence of unknown settlements built by a “lost” pre-Hispanic civilization, resolving a long-standing scientific debate about whether As to whether the region can sustain a large population, a new study finds.
The findings indicate the mysterious Casarabe people – who lived in the Llanos de Mojos region of the Amazon Basin between 500 and 1400 AD – were much larger than previously thought, and had developed an extensive civilization that adapted to unique environments. They lived according to a study published online Wednesday (May 25) in the journal Nature (opens in new tab) ,
The study researchers used aerial lidar – “light detection and ranging,” in which thousands of infrared laser pulses are bounced every second to reveal archaeological structures beneath dense vegetation – and to map roads, pathways, reservoirs. Several unknown settlements were discovered within the network and canals that centered on two very large Kasarabe settlements, now known as Kotoka and Landivar.
“In an hour of walking, you can walk to another settlement,” study lead author Heiko Prumers, an archaeologist at the German Archaeological Institute in Bonn, told Live Science. “This is an indication that the area was very densely populated in pre-Hispanic times.” Prumers and his colleagues have studied the Casarbe ruins in the region, now part of Bolivia, for more than 20 years.
ancient landscape
Map of the Llanos de Mojos savannah and Casarabe culture area. (Image credit: H. Prumers / German Archaeological Institute) The Llanos de Mojos region is a lowland tropical savanna in the southwest of the Amazon Basin. It has distinct wet and dry seasons each year – the driest months do not receive rain, but during the rainy season between November and April most of the area is flooded for months at a time.
Spanish missionaries in the 16th century found only isolated communities living there, and scientists had assumed the area’s pre-Hispanic populations were similar, Prumers said. Earthworks were found in the 1960s, but many scientists dispute whether they were ruins or natural features.
But the latest discoveries eventually refuted the idea that the area was sparsely populated, and show that the Kasarbe people instead established “low-density tropical urbanism” over a vast area, he said.
Co-author Carla James Descending from the central pyramid of the Betancourt Kotoka site. (Image credit: H. Prumers / German Archaeological Institute) The smaller Casarabe settlements could have been home to thousands of people, and 24 are now known — nine of them found for the first time in a recent lidar study, Prumers said.
The settlements were linked by roads and bridges, and were built in roughly concentric circles around the two major Casarabe sites at Kotoka and Landivar; He said that both were known before, but their true extent has now been revealed by Lidar.
The kotoka and the landivar were each centered on ceremonial sites, with large raised platforms of earth, on top of which were huge pyramids. The religious beliefs of the Casarabe people are unknown, but studies suggest that the platforms and pyramids were oriented north-northwest – in the same direction as the Casarabe burials found. “So there must have been a ‘world view,’ but nothing is known about that,” Prumers said.
lost civilization
A lidar image of the Cotoca site (Image credit: H. Prumers / German Archaeological Institute) An unusual feature of the settlements is that the Casarabe built them within a massive infrastructure of canals and reservoirs to manage the water.
Along with roads and causeways, these waterways diverged in all directions from major settlements such as Kotoka and represent a major investment in landscape management and labor mobilization, the researchers wrote in the study.
Prumers said the system could be used to control seasonal flooding of the region, allowing the cultivation of maize and other crops in raised areas; and it is possible that some reservoirs were used for fish farming, which would have been an important source of protein For the Casarabe people.
Trimble APX-15 UAV with GNSS Riegl VUX-1 scanner attached to a Eurocopter AS350 helicopter. (Image credit: H. Prumers / German Archaeological Institute) And he speculates that the lack of water may have played a role in the end of the Kasarabe civilization, in about 1400 AD, 100 years before the arrival of the Spanish. This is possible because the water management system relied so heavily on floods or other sources of water that it – and the civilization that depended on it – fell apart during a prolonged dry period. changing climate They said.
Michael Heckenberger, University of Florida anthropologist who was not involved in the research, but who has extensively studied (opens in new tab) Archaeology of the area, said the findings verified that the Casarabe people were organized in a type of low-density urbanization. “The archeology, chronology and dating are very well described on and off,” he said.
He notes that similar civilizational structures have now been found in other tropical regions that were once considered unsuitable for ancient civilizations, such as Spell in pre-Hispanic Mesoamerica.
Furthermore, the use of lidar to reveal the extent of the archaeological record in such areas is a major advance. “Lidar has been able to create a really clear synthetic picture of what a full-scale urbanized Amazonian landscape might look like,” Heckenberger told Live Science. “It really is a remarkable achievement.”
Originally published on Live Science.
