Dinosaurs Kill Asteroids in Today’s Jungle Jungle Births
It looked like the tropical jungle of Colombia very different from 66 million years ago. Today, the humid ecosystem and biodiversity are littered with plants and covered with a thick tile that blocks the light from the leaves and branches. Notably, there isn’t dinosaurs. But before the dinosaurs moved away with the Chicxulub impact, signaling the end of the Cretaceous era, things were very different. Coverage of the surrounding plants was relatively scarce, and a set of conifers called it home.
Using fossilized plant remains, a team of researchers studied how the rainforest’s past and the asteroid formed present-day jungles. The examination, published in Science on April 1, it was led by scientists at the Smithsonian Tropical Research Institute (STRI) in Panama and assisted by scientists from the Negaunee Institute for Plant Conservation Science and Action at the Chicago Botanical Garden.
“The forests disappeared due to the ecological catastrophe … and then the returning vegetation was dominated by flowering plants,” said Mónica Carvalho, the first postdoctoral fellow at STRI and Rosario University in Colombia and in an interview with Rosario at the University of Colombia. Ars.
The research began 20 years ago, when several teams in the group collected and analyzed 6,000 leaves and 50,000 fossil pollens from Colombia. By looking at these fossils, the group was given the opportunity to discover the types of plants that exist before and after the asteroids hit the planet. This sequence represents the biodiversity of the region between 72 million and 58 million years ago, covering it before and after the impact. “It took us a long time to gather enough data to have a clear picture of what was happening at the time of the disappearance,” Carvalho told Ars.
While the study focuses on Colombian fossils, Carvalho said researchers can get a clear idea of what happened in tropical jungles in other parts of Central and South America, although the effects of the asteroid’s impact are somewhat variable from region to region. “It’s a bit changeable. We still don’t know why some places were affected more than others, ”he said.
Then asteroid It hit the ground, killing almost half of the plant species in Colombia; the fossil pollen of these species was stopped at that point. Tropical forests began to be taken over by ferns and flowering plants, although they had a previous impact, they were less common than they are today. Conifers, by comparison, effectively disappeared.
Beyond the presence of conifers, the tropical forests of the past were much rarer than the more modern ones. Today’s jungles have thick tiles, and their inner plants are spaced apart, which means more plants transpire water into the atmosphere. This results in higher levels of humidity and cloud cover. According to Carvalho, the relative lack of moisture in previous forests means that the regions are much more fertile than they are today.
But the low-productivity forest remained in place until it hit the asteroid. “We’ve seen forests change their structure after the impact,” he said.
Researchers have several hypotheses as to how this change occurred. It is the first dinosaurs caused the forests to be denser; there could have been fewer animals consuming the plants or trampling them from the bush, allowing the leaf to grow relatively uncontrollably. The second idea is that shortly after the asteroid collided with the planet, a selective extinction of conifers occurred in the tropics; simply, couples who had flowers could have less than after the impact.
The third is that the effects of the catastrophe could have fertilized the soil. The tsunami events that followed the impact could have carried debris and sediment from surrounding areas with high carbon and shallow seas. Burning forest fires could send ashes into the atmosphere, and when it finally settled on the ground, it could be a kind of fertilizer. Flowering plants grow better than conifers on high-nutrient soils, Carvalho said. He pointed out that all of these hypotheses, or two of them, could be true at the same time.