The dinosaurs were already suffering from an evolutionary decline 50 million years before the asteroid disaster pushed them to extinction, according to a study published on April 18 in the journal Proceedings of the National Academy Of Sciences. The dinosaurs lost their ability to evolve that could have saved them from the environmental consequences of the impact.
The new study speculates that the break-up of continental land masses, constant volcanic activity, and other ecological factors contributed to this evolutionary decline. Moreover, older species of dinosaurs were going extinct more quickly than newer ones and while all dinosaurs were losing their edge, the patterns of species loss were different for each kind.
Researchers at the Universities of Reading and Bristol in the UK cite that long-necked sauropods suffered the fastest decline. On the other hand, theropods like the Tyrannosaurus rex were more likely the ones who have suffered from a gradual decline.
“Our work is ground-breaking in that, once again, it will change our understanding of the fate of these mighty creatures,” says lead researcher Manabu Sakamoto, a palaeontologist at the University of Reading. “While a sudden apocalypse may have been the final nail in the coffin, something else had already been preventing dinosaurs from evolving new species as fast as old species were dying out.”
“Our study strongly indicates that if a group of animals is experiencing a fast pace of extinction more so than they can replace, then they are prone to annihilation once a major catastrophe occurs,” adds Sakamoto. “This has huge implications for our current and future biodiversity, given the unprecedented speed at which species are going extinct owing to the ongoing human-caused climate change.”
But do not feel bad about the dinosaurs. Chris Venditti, an evolutionary biologist from the University of Reading, asserts that this decline paved the way for mammals which humans belong to, to thrive before the impact, ultimately dominating the Earth.