According to the researchers, this insight helps understand why some animal and plant species became extinct but not others. “Not all life forms died in that meteorite impact,” he says during the course of the meteorite impact. “How did all these dinosaurs disappear? And why did groups recover faster in the Southern Hemisphere than in the Northern Hemisphere? Now we say: We think the season played an important role in this.”
bones
During and her colleagues based their conclusion on examining the jaw bones and spines of six fish (sturgeon), which they believe died on the day of the impact. While excavating those bones in the US state of North Dakota, about 2,500 miles north of the meteor impact.
“These bones come from the inner bend of a river that was flowing there 66 million years ago. These fish are the direct victims of the impact. Their gills contain rocks that melted by the impact, thrown into space and about 15 to 30 minutes later. The impact returned to Earth in a crystallized form.” . The rock was not found in the digestive tract, indicating that the fish died almost instantly after the impact.
Annual episodes
While he explains that the bones of these fish contain a kind of growth ring, comparable to the growth rings on trees. “You can tell by the structure of the bones when the fish ate a lot (in summer), when less (in spring and autumn) and when not (in winter). The chemical composition also varies throughout the year. Both show us: the fish died in the spring.”
