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Dinosaurs weren’t in decline at the time of their extinction, caused by an asteroid that hit Earth 66 million years ago, according to a new study.
The research, conducted by the University of Bath and the Natural History Museum, contradicts previous theories and concludes that dinosaurs could have continued to dominate the planet had the impact not occurred.
Scientists collected a number of different dinosaur family trees and used statistical models to assess whether each of the major dinosaur groups was capable of producing new species at that time.
Their study, published in the Royal Society Open Science journal, found that dinosaurs weren’t in decline before the asteroid hit, contradicting some previous research.
He also found that certain groups of dinosaurs, such as hadrosaurs and ceratopsians, were “thriving” and would not have become extinct by then.
Lead author Joe Bonsor is pursuing his doctorate jointly at the Milner Center for Evolution at the University of Bath and the Natural History Museum.
“Previous studies by others have used various methods to draw the conclusion that dinosaurs would still be dead, as they were in decline towards the end of the Cretaceous period,” he said.
“However, we show that if you expand the dataset to include newer dinosaur family trees and a wider range of dinosaur types, the results don’t really all point to this conclusion, in fact only about half of them do. “.
Dinosaurs were widespread globally at the time of the asteroid impact, at the end of the Late Cretaceous period, and were the dominant animal form of most terrestrial ecosystems.
It is still controversial among paleobiologists whether dinosaurs were in decline at the time of their extinction.
Researchers from the latest study say it is difficult to assess dinosaur diversity due to gaps in the fossil record.
This may be due to factors such as which bones are preserved as fossils, how accessible the fossils are in the rock for them to be found, and the locations where paleontologists look for them.
In the study, the team used statistical methods to overcome these sampling biases by looking at the speciation rates of dinosaur families rather than counting the number of species in the family.
“The main point of our article is that it is not as simple as looking at some trees and making a decision: the big inevitable bias in the fossil record and lack of data can often show a decline in species, but this may not be. reflection of reality at that time, “Bonsor said.
“Our data currently do not show that they were in decline, in fact some groups such as hadrosaurs and ceratopsians were thriving and there is no evidence to suggest they would have died 66 million years ago if the extinction event had not occurred.”
The research was funded by the Leverhulme Trust and the Natural History Museum.
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