An asteroid impact 66 million years ago should be solely responsible for the end of the dinosaurs. This is shown by the results of a study by the German Research Center for Geosciences (GFZ). The research was in agreement that a collision with an asteroid triggered the mass extinction on our planet. However, it was suspected that the ecosystems were already burdened by increasing volcanism - this could now be refuted, according to the study.
"Our data speaks against a gradual worsening of living conditions 66 million years ago," said Michael Henehan from the GFZ. The collision of an asteroid with the planet killed up to 75 percent of all species 66 million years ago.
Fossil remains of tiny calcareous algae not only provide information about dinosaur extinction, but also show how the oceans recovered after the fatal asteroid impact that formed the Chicxulub crater in the Gulf of Mexico. Henehan and his team at Yale University reconstructed the environmental conditions in the oceans with fossils from deep-sea drilling cores and rocks formed at that time.
Oceans became sour
As a result, the oceans became so acidic after impact that organisms producing lime shells failed to survive. As this led to the extinction of many forms of life in the upper layers of the oceans, carbon uptake was halved by photosynthesis in the oceans. "Before the impact, we could not detect any increase in acidification of the oceans," Henehan said.
According to the researchers, this condition lasted for tens of thousands of years - then calcified algae again. However, it took several million years for the fauna and flora to recover and the carbon cycle to reach a new equilibrium. The impact of the asteroid marks the boundary of two geological eras - the Cretaceous and the Paleogene.
The study was largely conducted at Yale University, financially supported by the Yale Peabody Museum. It was published in the journal Proceedings of the National Academy of Sciences .