Dinosaurs and fossilized Efichianodos are familiar with the meteor strike that wiped out Tyrannosaurus rex and all nonviolent dinosaurs nearly a million years ago. But it is often overlooked that the effect also destroyed the entire ecosystem. A new study shows how, as a result of these casualties, another particularly profound evolution led to the result: the emergence of the Amazon rainforest in South America, the most spectacularly diverse atmosphere on Earth. Yet the bounty of the tropical species and habitats of the Amazon now threatens its own survival due to unprecedented destruction from human activity, including clearing land for agriculture.
The new study, published in Science on Thursday, analyzes the remains of thousands of plants, says Peter Wilf, a geologist at Pennsylvania State University, who is not involved in the research. The authors pointed out that the extinction of dinosaurs was also a major reset event for neotropical ecosystems, leading their evolution to a completely new path, leading to extraordinary, diverse, spectacular and endangered rainforests in the region today. . “
This insight, Wilfe added, “provides a new impetus for the conservation of tropical living evolutionary heritage that supports human life with millions of living species.”
Carlos Geramilo, a paleobiologist and co-lead of the study at the Smithsonian Tropical Research Institute in Panama, agrees that meteorite evolution and environmental influences have implications for today’s rapid, man-made destruction of the Amazon rainforest and other major habitats. Towards the planet. He says, “We can combine this nowadays, because we are also changing landscapes, and it lasts forever – or at least for a long time.”
Analysis of approximately 20,000,000 pollen grains and 1,000,000 fossil fossils shows that the meteorite that destroyed the non-Navyan dinosaurs also developed the Amazon rainforest.
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Modern day rain forests are integral to the life of the earth. The Amazon, in particular, plays a crucial role in controlling the planet’s freshwater cycle and climate. Yet paleontologists in Western Europe and North America have paid little attention to tropical forests, instead to temperate latitudes. Even many academic and amateur fossil hunters tend to write for lost reasons of finding warm, wet locales, as they assume that conditions there will not save enough time to fossilize organic matter. “It is this combination of factors that has led us to the absence of so much data in the tropics,” says Bonnie Jacobs, a palebiologist at Southern Methodist University who co-authored a published reference essay with a new study of science.
Scientists already know that the effects of a meteorite collision and its aftermath – at least in temperate regions – differ from the local conditions and the distance from the crater in the Yucatan Peninsula of Mexico. For example, the forests of New Zealand escaped relatively easily. But researchers had no idea how the phenomenon could change Africa’s tropical rainforests or, yet, South America’s.
Along with most of his co-authors, Jaramillo is from Colombia and especially wanted to explore the origins of his country’s tropical forests. The new study, which he envisioned as an undergraduate student, represents almost 12 years of effort. “It took us a long time,” he says, “because we had to start from scratch.”
The whole tree is almost never preserved in the fossil record, so Jaramillo and his companions turned to fossil pollen and went out for insight. Pollen preserves well over time and is widespread in the fossil record. Like the leaves, they differ morphologically in species, helping researchers determine what types of plants lived in the ancient habitat.
Jaramillo and his allies discovered 53 sites in Colombia for rocks formed during the late Cretaceous period before the meteor strike, and another 10 million formed during the Paleogene period in subsequent years. From these rocks, the team collected and analyzed approximately 50,000 remnants of pollen grains and 6,000 fossilized leaves so that it could bring out the types of plants. Recent isolated findings suggest that the leaves of plants receiving more light have a higher density of veins, as well as a higher proportion of naturally occurring isotopes called carbon 13. Researchers studied those features among the collected fossils to integrate the region’s past formations into one another. Forests.
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Their findings paint a picture of the sudden, catastrophic destruction of life after the impact – even of a phoenix-like rebirth millions of years later. Before the meteor, the authors determined, the forests of South America have a bright open canopy supporting many green conifers and the lush green underside of ferns. Dinosaurs will probably play a key role in maintaining these Cretaceous forests by cutting down trees and clearing vegetation, among other things. In the moments of influence of the Chickasulab meteorite, however, this ecosystem was inevitably changed. The fire, which had probably been burning for many years, engulfed the forests of southern South America. According to the authors’ calculations, many animals supported them, with a total of 45 percent of the continental tropical plant species disappearing.
It took six million years for forests to return to their diversity levels before meteors, and the species that gradually re-emerged were quite different than before. Legumes – plants that symbolize the bacteria that allow them to fix nitrogen from the air – first appeared, and they enriched the previously nutrient-deficient soil. This rush of nitrogen, along with phosphorus from meteorite rye, enabled other flowering plants to bloom with fungi and replace conifers. As the flower species competed for light, they formed a dense canopy of leaves and created the layered Amazon rain forest we know today, characterized by a top productivity blanket and a dark understry at the bottom.
La Brava tar pits and museum paleologist Reagan Dunn in Los Angeles, who were not involved with the new study, agree that his findings are key not only to disclosing the past, but also to put current anthropological threats in perspective. He particularly notes the authors’ calculations that 45 percent of plant species have become extinct after meteor collisions, as “current estimates suggest that at least several species of these plants will be endangered globally in the Amazon Basin by human activity alone in the next 30 years. ”
“The question remains: how will human impact forever change the composition and function of the Amazonian forests?” Says Dunn.
Jacobs says the new findings show how mass extinction events can change “the way of everything.” She added that today we are in the midst of another such phenomenon, but this one is driven by a single species – and it is not far from a crater of figurative effect because “omnipresent is omnipresent.”
Yet unlike the mass extinctions in the past, Jacobs says, this time “we are not powerless to stop it.”
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