Life on earth is a delicate thing. One of the pathways it takes is asteroids and balms, the most influential group of land animals on our planet.
If it weren’t for the 10-kilometer-wide meteorite that spanned Earth about a million years ago, dinosaurs would be able to maintain their dominance over the earth. If we talk about mammals like us, we have never had a chance to raise them.
The results are the latest in a long and drawn-out debate on the extinction of non-avian dinosaurs.
While the planet Chixulab and the consequences of its effects – which blocked the sun’s rays and induced cooling in the global atmosphere – are generally considered the main candidates for large-scale Cretaceous extinction, some recent evidence suggests that dinosaur species were already in decline by millions. Years ago.
The authors of these findings claim that “overwhelming support for long-term decline in all dinosaurs and in all three major dinosaur groups”, but among paleontologists, the basis for that idea is hardly overwhelming. In fact, it is very controversial.
Since the idea was first introduced, many other lines of research have disagreed with its conclusion – not only with the necessary information itself, but also with the drawn interpretation.
The bias of dinosaur fossils and specimens means that we can take samples of some Cretaceous dinosaurs, while giving an over-understanding of the presence of others.
J. Bonser, a paleontologist at the University of Bath, explains, “Previous studies by others have used various methods to draw conclusions that dinosaurs would have died anyway, as they were breaking down towards the end of the Cretaceous period.”
“However, we do show that if you expand the dataset to include a wider group of dinosaur family trees and dinosaur types, the results don’t really pay attention to this conclusion – in fact only half of them do.”
Instead of calculating the number of dinosaur species at that time using fossil records, the team used statistical methods to look at the rate of specification in dinosaur families.
By analyzing thousands of family tree compounds in 12 dinosaur families, the researchers tested whether species diversity is slowing down, staying the same or happening faster before the planet’s influence – a sign that could tell us how to replace extinct dinosaurs. is coming.
Of all the 2,727 specification models, only 518 (less than 20 percent) showed an undeniable terminal reduction before the asteroid effect.
Even when the authors consider the terminal reduction and no reduction people on the border it is more than half the models that will support a more stretched extinction.
As such, the team says they are skeptical about the terminal extinction theory, instead suggesting that dinosaur diversity would have remained high during the late Cretaceous, despite the species richness variation between branches.
“The main point of our paper is that it’s not as easy as looking at a few trees and making a decision. Large compelling biases and lack of data in fossil records often show a decline in species, but this may not be a reflection of reality at the time,” says Bonser.
“Our data do not currently show that they were declining, in fact there is no evidence to suggest that some groups, such as the Hros drossor and the Seratopsian, would have died 66 million years ago if they had not become extinct.”
The results are corroborated by another recent study, which found that North American dinosaur habitats did not decline during the late Cretaceous.
Fossil outputs are small for this region, which means we are probably sampling the area and underestimating its species richness.
Systemic sampling errors like these are obscure in paleontology and, to some extent, inevitable. But it also has its limitations against the total number of species depending on the richness of the species.
For beginners, there is no relationship between dinosaur evolution and specific rates of extinction. That is the assumption we are making in the dark.
The authors of the new paper acknowledged, “We may never know the specifics and actual levels of extinction of Mesozoic dinosaurs, but focusing more on filling in the gaps in the fossil record would be the primary way paleontologists will continue to build.”
The new paper once again emphasizes the myriad gaps and biases of our knowledge, and the authors are constantly calling for research that is detailed, regionally controlled, and well-distributed in a timely manner to recreate a possible holistic history.
The study was published in Royal Society Open Science.
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