In my 2019 book America Before I devote seven chapters, more than 90 pages, to the implications of recent remarkable discoveries in the Amazon rainforest. These include great cities overgrown by the jungle, immense earthwork mounds and henges, astronomically-aligned megalithic sites, evidence of sophisticated agricultural techniques and evidence of advanced scientific knowledge of the medicinal properties of plants.
In Chapter Fifteen, “Sacred Geometry”, I draw particular attention to “clusters of monumental earthworks… shaped as perfect circles, rectangles and composite figures” that have been revealed by LiDAR (Light Detection and Ranging) surveys in the Brazilian Amazon. Now, far to the south in the Bolivian Amazon, a new LiDAR survey has unveiled further networks of mysterious monumental structures.
Published in Nature on 25 May 2022 (see here: https://www.nature.com/articles/s41586-022-04780-4 and here: https://www.nature.com/articles/d41586-022-01458-9), the new findings identify two sites in particular, Cotoca and Landivar as the most important:
These two large settlement sites were already known, but their massive size and architectural elaboration became apparent only through the lidar survey.
The scale and elaboration of civic-ceremonial architecture are key aspects of the large settlement sites. Massive earthen platform buildings— some of which are U-shaped —and conical pyramids rise more than 20 m above the surrounding savannah on top of artificial terraces of up to 6 m in height. The orientation of the buildings that constitute the civic-ceremonial centres of the two large settlement sites is very uniform towards the north-northwest. This probably reflects a cosmological world view…
The paper’s authors further note that the core area of Cotoca totals 570,690 m3– making it more than ten times larger than the famous Akapana pyramid of Tiwanaku in the Bolivian Andes.
Moreover, the LiDAR survey shows Cotoca to have stood at
the centre of an area of approximately 500 km2, half forest and half savannah, which includes 18 other monumental sites… The…role of Cotoca as a primary site is… underlined by the impressive system of canals and causeways that radiate from the base platform in all of the cardinal directions.
By any measure, therefore, what the new research in the Bolivian Amazon has brought to light are the remnants of a truly monumental civilization. “Our results”, the authors conclude:
put to rest arguments that western Amazonia was sparsely populated in pre-Hispanic times. The architectural layout of large settlement sites … indicates that the inhabitants of this region created a new social and public landscape through monumentality.
Archaeologists attribute Cotoca and Landivar to the so-called “Casarabe culture” (we don’t know what this culture called itself) and date them to between AD 500 and AD 1400. This time-frame is not derived from excavations at Cotoca and Landivar themselves but from excavations at a number of similar monumental sites in the same general area. Carbon dates more than two thousand years older than the oldest Casarabe dates have been found but are ignored as “outliers”:
Excavations at monumental sites Salvatiera and Mendoza have revealed complex stratigraphies that bracket the chronology of the Casarabe culture from AD 500 to 1400. The 94 radiocarbon dates from Salvatierra and Mendoza, as well as 50 additional radiocarbon dates previously published for other Casarabe culture sites date the construction and use of these sites to this period. The dates prior to this period are mostly outliers but, in some cases, also come from samples taken from the sterile soil beneath the earliest platform buildings. They date natural events or perhaps the ephemeral presence of non-ceramic cultures prior to the construction of the Casarabe culture sites.
The archaeological investigations thus far undertaken into the Casarabe culture deserve praise for being thorough and detailed, but such a sophisticated civilization – no lesser word will do — does not simply spring up out of nowhere. There must be a background to it, either beneath the earliest platform buildings or in the as-yet unexcavated sites that the LiDAR survey has pinpointed in the surrounding jungle.
The Amazon, as I wrote in America Before, remains largely a terra incognita to archaeologists
Even in these days of man-made ecological disaster let us remind ourselves that 5.5 million square kilometers of the Amazon basin is still covered by rainforest. To put that in perspective, picture Mexico, Guatemala, Belize, Honduras, and El Salvador. Taken together they encompass 2.22 million square kilometers—not nearly enough—so we will need to add on India with more than 3 million square kilometers to get an imaginary realm almost equivalent in size to the Amazon rainforest. My point here is that when we consider the Amazon as an archaeological project, its scale is comparable to Mexico, Guatemala, Belize, Honduras, El Salvador, AND India all added together, and all, in addition, entirely covered by dense rainforest and therefore difficult and expensive to access. Moreover, unlike Mexico, Guatemala, Belize, Honduras, and El Salvador, where the famous Maya civilization flourished, and unlike India with its ancient cities and temples, there was… no inducement for archaeologists to invest scarce time and money on excavations in the Amazon while it was believed that nothing of great interest would be found there. At the close of the second decade of the twenty-first century no serious archaeologists are still thinking that way! The state of affairs they’ve inherited, however, means that huge swaths of the Amazon, encompassing millions of square kilometers, have never been subject to any kind of archaeological investigation at all.
This is a wider problem than the Amazon. For example, sea level rose 120 meters when the Ice Age came to an end with the result that 27 million square kilometers of land that was above water at the last glacial maximum 21,000 years ago is under water today. These submerged continental shelves were prime seafront real estate during the Ice Age, yet only a few tiny slivers of them have ever been subject to any kind of marine archaeological investigation. Again, this is because, like the Amazon, access requires special preparations, equipment, and transportation and also because of a similar belief that whatever would be found as a result of these costly investigations would not add greatly to what is already known.
I’ll say nothing about Antarctica, with its 14 million square kilometers entirely virgin to the archaeologist’s spade. The almost universal agreement that humans could never have lived there in the past might or might not be correct, but we’ll never know for sure unless we look.
We do know that the Sahara desert, presently occupying an area of about 9 million square kilometers, had a very different climate during the Ice Age, and in the early millennia of the Holocene, than it experiences today and that there were long periods when it was well watered and fertile, with extensive lakes and grasslands and abundant wildlife. It is near enough to Egypt and the other great centres of early civilization in North Africa and the Middle East to have attracted the attention of archaeologists, but like the Amazon and like the submerged continental shelves, access is difficult and expensive, placing serious practical limits on what can be achieved.
Part of our predicament, therefore, as a species with amnesia, is that huge areas of the planet that we know for sure were used by and lived upon by our ancestors—the submerged continental shelves, the Sahara desert, the Amazon rainforest—have, for a variety of practical and ideological reasons, been badly served by archaeology. The truth is, we know VERY little about the real prehistory of any of these places, and the tiny patches that have thus far been surveyed and excavated within them are no legitimate basis upon which to draw conclusions and express certainties about the vast areas that remain unsurveyed and unexcavated.