66 million years ago a huge asteroid hit the Yucatan peninsula (Mexico) and caused the disappearance of more than 70% of the species that lived on our planet. It was not the most dramatic, but this massive extinction of the Cretaceous-Paleogene is the most famous of all, since it originated the disappearance of the dinosaurs.
This fact would determine the subsequent natural history of the Earth: with the extinction of the so-called “kings of the Cretaceous” would be released many ecological niches that would occupy other species. For example, a study published in Nature Ecology & Evolution revealed that, after the annihilation of the dinosaurs, the small mammals that until then had been nocturnal began to be active during the day, a milestone that marked the evolution of this group of animals to which the human species belongs.
Surely many scientists would love to be able to peep through a peephole at that time and observe live everything that happened on the planet after the impact of the asteroid. Unfortunately, we can not visit the past, but the analysis of the crater sediments offers us a kind of journey through time and can give us clues about what happened at that time. The latest findings in this regard have just been published in the journal Nature , and reveal that, in the same area in which the meteorite hit, life recovered at an amazing speed.
A catastrophe of great magnitude
We are going to put ourselves in situation: we are talking about a swipe whose violence is equivalent to that of no less than a billion atomic bombs, which produced tsunamis between 100 and 300 meters high, earthquakes of magnitude higher than 11 on the Richter scale, acid rain, temperature increase and fires at distances of up to 4,000 kilometers from the crater. An authentic catastrophe.
However, the team of scientists that participated in this study reveals that, in the same Chicxulub crater, originated in the place of impact of the asteroid and with a diameter of 180 kilometers, life reappeared very few years later, and also the High productivity marine ecosystem recovered in the first 30,000 years, a comparatively short geological time. Other works had already recorded rapid recoveries in areas far from “ground zero”, such as Spain, southern France or Tunisia, but this is the first evidence of this fact in the impact zone itself, where the change in environmental conditions It was obviously much bigger.
The authors of the study are members of the Expedition 364 of the International Ocean Discovery Program (IODP) “Chicxulub: drilling the K-Pg impact crater” and have carried out their analyzes, which combine geochemical data with paleontological data in witnesses obtained after the drilling of the crater.
“This recovery is even faster than in other areas farther from the impact, and is a consequence of the important connection of the impact zone with open waters, which allows the rapid restoration of favorable conditions for the development of life”, explained Francisco Javier Rodríguez-Tovar, researcher at the University of Granada and one of the participants in the work. The discovery of fossil traces in the first sediments deposited after the impact has confirmed the rapid recovery of organisms that live on the seabed.
During the first days of June, members of the 364 Expedition, including Dr. Rodríguez-Tovar, will return to Mérida (Mexico) to visit the outcrops of the K-Pg boundary associated with the crater and address the next lines of research.