Feb 28, 2022 08:00:00

It turns out that the asteroid destroyed the dinosaurs because of 'spring', which is why mammals survived the meteorite impact.

It is known that 'dinosaurs' of various sizes and shapes such as Tyrannosaurus and Triceratops once lived on the earth. There is a strong theory that such dinosaurs were 'catastrophically damaged by the collision of a large-scale asteroid and became extinct' about 66 million years ago. Did other species, such as mammals, their ancestors survive? ”Has long plagued scientists. A paper published in

Nature in February 2022 announced that the damage caused by the collision of asteroids occurred in 'spring', arguing that the timing was the cause of the extinction of dinosaurs and the reason why mammals survived. increase.

The Mesozoic terminated in boreal spring | Nature
https://www.nature.com/articles/s41586-022-04446-1

The cause of the dinosaurs' destruction is that they could not withstand the climate change during the ice age, and that they had declined before the asteroids collided, but the asteroids that collided with the Earth about 66 million years ago were the cause. The theory that thinks that it is the most influential. A huge asteroid breaks up a wide area with a shock wave, burns it at a temperature of hundreds or thousands of degrees, and a vaporized mantle covers the earth to block sunlight. In this way, everything from dinosaurs to microorganisms was hit hard by the ecosystem.

What happened on 'the day when the dinosaurs were mass extinct'? --GIGAZINE

Such asteroid damage has completely destroyed ancient dinosaurs, pterosaurs, marine reptiles such as spinosaurus, and ammonites, while many mammals and birds. , Reptiles such as crocodiles and turtles have survived. To unravel this mystery, Melanie Duaring of Uppsala University in Sweden conducted a study to obtain information from fossilized fish specimens, 'When was the moment of the collision?'

In the study, a cross-sectional view of the sample bone was examined under a microscope to analyze 'when the bone growth stopped'. The fossil fish found in North Dakota, USA, is treated as a 'sample that died at the time of the asteroid collision' because of the traces of the glass spheres that were generated by the collision of the asteroid.

As a result, it is concluded that all the fish treated as samples died in the 'spring', the earliest stage of the most favorable growing season. In December 2021, a research team at the University of Manchester in a

similar study showed a mass extinction of 'spring' by X-ray analysis of fish bones, and this study provides new support. Although the paper was later than the University of Manchester, the submission of the research itself was considerably earlier by the collaborative research team including Uppsala University, and the research data and conclusions were not diverted and similar conclusions were shown as completely different ones. It was said that it was done.

Similarly, the annual feeding pattern of fish that can be analyzed from bones shows that the fish that suddenly stopped living died in 'spring', 'before the feeding period reached its climax'. Mr. Dualing describes. Since the plankton ingested by fish is linked to the growth record of the skeleton, analysis of the annual growth rate from the bone record reveals that the feeding period has not been reached.

The fossils and strata used in the study are from North Dakota, northern United States. Therefore, it is considered that the creatures in the Northern Hemisphere were particularly vulnerable due to the damage to the asteroid in the spring, which is ahead of the winter and before breeding and growth. On the other hand, the southern hemisphere season is 'autumn', which was a reserve of hibernation for winter, and the damage in the event of a collision was suppressed by evacuating to burrows and caves, so the ecosystem of the southern hemisphere is twice that of the northern hemisphere. The paper states that it recovered at the speed of.