An international team of scientists modeled the life of dinosaurs on Earth and concluded that their population began to decline before the mass extinction. The researchers suggested that this was due to the cooling of the planet.
In a new study published in the journal Nature Communications, an international team of scientists, including the University of Bristol, has shown that dinosaurs had been declining for about ten million years before the extinction.
“We looked at the six most numerous dinosaur families throughout the Cretaceous period, from 150 to 66 million years ago, and found that they all evolved and reproduced. Then, 76 million years ago, there was a sudden decline. The rate of extinction has increased, and in some cases the rate of emergence of new species has decreased, ”the scientists note.
The team used Bayesian modeling techniques to account for several types of uncertainties, such as incomplete fossil records, fossil age gaps, and evolutionary models. Models have been run millions of times to account for all possible sources of error and to determine if analyzes converge with the most likely results.
Their findings were confirmed, after which the researchers moved on to the possible reasons for the decline in the dinosaur population. They identified two factors: the cooling of the earth’s climate, which made the existence of dinosaurs accustomed to warm temperatures more difficult.
At the same time, the loss of herbivores made ecosystems unstable and prone to cascading extinction. Scientists also found that long-lived dinosaur species were more prone to extinction, possibly indicating that they could not adapt to new conditions on Earth.
“Dinosaurs were mostly so huge that they probably didn’t know about the existence of small furry mammals. But mammals began to increase the number of species even before the extinction of dinosaurs, and after the impact they had a chance to create new types of ecosystems that we see today, ”added the scientists.