Did you know that part of the Amazon has once been covered by the sea? Or that the region has formerly been the home of giant animals over four meters tall? Or that the beginning of human occupation in the Amazon, by Asian migrant peoples, dates back approximately 14,000 years?
All these peculiar aspects of the of the region’s remote past and currently known as the Amazon biome have been uncovered by two fields of study: Paleontology, which researches past life on Earth through fossils, and Archaeology, which investigates material remains of human presence in order to understand the lifestyles of ancient societies.
It was precisely to share with the public some of the region's paleontological discoveries that the Museu Paraense Emílio Goeldi (MPEG) [Emílio Goeldi Museum of Pará] created the exhibition “Fóssil Vivo” [Living Fossil], open until December 31st of this year at the museum’s Zoobotanical Park. The exhibition uses augmented reality and virtual reality technologies to provide immersive experiences, allowing participants to explore two distinct periods in the geological history and biodiversity of the Amazon.
One of these periods is the geological formation known as Formação Pirabas [Pirabas Formation], dating from the Miocene epoch, around 23 million years ago. At that time, the northeastern part of the state of Pará was covered by the sea. This was revealed through the identification of marine fossils in areas such as Salinópolis, Capanema, Primavera, and São João de Pirabas. Visitors can view fossils and augmented reality representations of animals that inhabited the area, such as sharks, rays, and crabs.
The other period portrayed in the "Living Fossil" exhibition is more recent, it dates from the Pleistocene epoch, and shows the so-called megafauna: large animals that lived in the region about eleven thousand years ago. Through virtual reality glasses, visitors can see creatures like the giant sloth, the mastodon, or an ancestor of the armadillo, all of which measured about four meters in height. These animals coexisted with humans and a landscape vastly different from the current tropical rainforest.
"At that time, there was an environment called savannah-like, with undergrowth vegetation. Scientific data shows that temperatures in the Amazon were somewhat cooler, promoting this type of vegetation and the spread of large animals, which existed not only in the Amazon but in various parts of the American continent," explains Ana Paula Linhares, a paleontologist at the Goeldi Museum.
The Amazon was once close to the South Pole
The Paleontological Collection of the Museu Paraense Emílio Goeldi holds relics from much earlier periods, from a time when the Earth was not divided into six continents. "We have fossils from the Amazon Basin dating back more than 400 million years, from the Paleozoic era. These are fossils from a time when the planet consisted of a single supercontinent – the Pangaea. The Amazon, for example, was not located in the tropical region but was, instead, somewhat closer to the South Pole. I study shell fossils from a group called brachiopods from this period, which lived in relatively shallow seas due to the geological configuration of that time. These fossils are part of a permanent exhibition called Amazonian Diversities at the Zoobotanical Park", Linhares explains.
"We also have fossils from the Cenozoic era, including some from dinosaurs, in the Amazonian Diversities exhibition. Additionally, there are specimens from the Solimões Formation, which is somewhat similar to the Pirabas Formation but was no longer a marine environment, but fluvial-lacustrine," adds the paleontologist. The Solimões Formation is located where the state of Acre is now and corresponds to the late Miocene period, between 6 and 9 million years ago.
Ana Paula Linhares explains that, during the Solimões Formation period, a very drastic event occurred in the Amazon: the rise of the Andes mountain range, located on the western coast of South America. "This has not only changed the configuration of the Andes region but also of the Amazonian plain because it altered the drainage of the region’s rivers. Previously, the rivers of the Amazon basin flowed to the left side, towards what is now the Andes mountain range. When the mountains formed, the rivers could no longer flow in that direction, and the drainage reversed. We have fossils from that period that help tell this story," she clarifies.
The planet undergoes constant cyclical changes
According to the paleontologist, many questions arise about why the megafauna has disappeared. She points out that the planet constantly goes through cycles that benefit certain groups of living beings while disadvantaging others.
"Since the first life forms were evidenced – bacteria – three billion years ago, there have been various transformations in environments, landscapes, and climate, as well as the emergence and extinction of numerous groups of living beings. Earth, naturally, undergoes climatic cycles that shape the landscape and the distribution of animals, plants, fungi, etc.," she observes.
She adds that during the megafauna period, the vegetation was different, and when temperatures rose, some botanical groups could not survive. "As a result, the environment was no longer as conducive to herbivores, which required specific feeding conditions. Furthermore, some research suggests that there was conflict between these animals and early humans. So, they did not die solely from natural causes due to climate changes. It wasn’t just one cause," the researcher clarifies.
Ana Paula Linhares emphasizes that climate changes have been taking place since the beginning of the planet’s existence, but they are now being accelerated by human activity. "All the eras that we know of, which supported life, went through climate changes. These are cyclical changes, but they are now being intensified by humans, through unorganized anthropogenic actions that are altering ecosystems and causing imbalances," she analyzes.
Indigenous history in the region is long-standing
Human occupation in the Amazon dates back about 14,000 years. Asian peoples migrated to North America and gradually dispersed until they reached South America. According to Anne Rapp Py-Daniel, a professor of archaeology at the Universidade Federal do Oeste do Pará (Ufopa) [Federal University of Western Pará], there are records from this period in Carajás, Pará, and in Rondônia, as well as from about 12,000 years ago in the Caverna da Pedra pintada [Painted Rock Cave] in Monte Alegre, also in Pará, where numerous rock paintings have been discovered.
However, the researcher says it is not appropriate to speak of a prehistoric Amazon, despite the temporal mark. "We don’t usually use the term ‘prehistoric Amazon’ because it carries various implications and biases, as if it were a population living without history, outside of time, or with connotations of inferiority. Instead, we talk about a long-standing indigenous history," she argues.
The archaeologist describes some key moments in this history. In addition to the discoveries dating back more than 10,000 years, constructive structures called sambaquis, composed of shells, animal remains, plants, and artifacts, were found, serving various purposes such as ceremonial, residential, or funerary.
"The oldest known sambaqui is Taperinha in Santarém, but we also have Monte Castelo in Rondônia, which is over 6,000 years old, and others in the Lower Amazon region, dating from between 6,000 and 4,000 years ago. Starting about 4,000 years ago, we begin to identify the Terras Pretas de Índio or anthropogenic dark earths, which developed as a result of intense, large-scale occupations, involving many people and extensive land management. From that time until around the year 1000 AD, there has been an intensification of occupations, with large villages and urban areas," Anne Py-Daniel informs.
Preservation of archaeological sites
Since 1961, the Instituto do Patrimônio Histórico e Artístico Nacional (Iphan) [National Institute of Historical and Artistic Heritage] has ensured the protection of Brazilian archaeological sites, in accordance with Federal Law 3,924. Currently, there are about 6,000 registered archaeological sites in the Amazon region, but Anne Py-Daniel estimates that 90% of what in fact exists has yet to be discovered.
In addition to the vast amount left to be studied, there is also the need to preserve what has already been identified. "Several regulations protect archaeological sites, but they are protected only up to a certain point. There are people mining at the sites or extracting dark earth or shells from sambaquis, which is considered a crime," the Professor says. The dark earths, formed from pre-Columbian human activity, are recognized for their high fertility.
Another concern is the protection of these sites against deforestation. According to a survey conducted by the website InfoAmazonia, based on Iphan records and deforestation rates studied by the Instituto Nacional de Pesquisas Espaciais (Inpe) [National Institute for Space Research], 71% of archaeological sites located in the forests of Legal Amazon are in deforested areas.
"What we see is that, especially in the southern Amazon, where there is this arc of destruction, a huge number of sites are being depleted for soy cultivation or road construction. We haven’t even been able to map the full extent of the destruction, which is happening at a faster pace than we can understand," the archaeologist regrets.
Understanding past to improve future
The threat to archaeological sites raises reflections on the fate of this heritage and the studies of human history in the Amazon. Studying the past allows us to answer questions about the present and envision the future, highlighting the importance of preserving these sites and generating archaeological knowledge.
In a similar way, paleontological studies connect us with future times. "If I understand the past of my region, I can project scenarios in comparison to the environmental changes we are experiencing today. Through studies and projections, we can attempt to foresee the consequences of the more pronounced changes we are now facing and work to mitigate these future effects. Understanding living beings, their evolution, and their environments helps us direct current studies and potentially reverse more extreme situations that could, unfortunately, lead to the disappearance of several species," concludes the paleontologist.
INSTITUTIONAL PARTNERSHIP
The production of Liberal Amazon is one of the initiatives of the Technical Cooperation Agreement between the Liberal Group and the Federal University of Pará. The articles involving research from UFPA are revised by professionals from the academy. The translation of the content is also provided by the agreement, through the research project ET-Multi: Translation Studies: multifaces and multisemiotics.
