Dinosaurs 'ran out of evolutionary steam' before they became extinct

Dinosaurs stopped evolving and taking advantage of their changing environment during their last 50 million years on Earth, scientists have learned.

They were not part of the Cretaceous Terrestrial Revolution around 100 million years ago, which saw the rapid expansion of many land animals and plants.

While flowering plants, lizards, snakes, birds and mammals evolved swiftly, the dinosaurs plodded behind. A short time later, they were extinct.

Researchers made the discovery after using powerful computer programs to produce a 'supertree' of dinosaur lineages.

The results showed the most likely pattern of evolution for 440 of the 600 known species of dinosaur.

Graeme Lloyd, one of the University of Bristol scientists who led the study, said: 'Supertrees are very large family trees made using sophisticated computer techniques that carefully stitch together several smaller trees which were previously produced by experts on the various subgroups.

'Our supertree summarises the efforts of two decades of research by hundreds of dinosaur workers from across the globe and allows us to look for unusual patterns across the whole of dinosaurs for the first time. It is the most comprehensive picture ever produced of how dinosaurs evolved.'

The findings, published today in the journal Proceedings of the Royal Society B, revealed that dinosaurs had a burst of diversification in the first 50 million years of their reign. Then their rate of evolution slowed down, and did not change.

Dinosaurs failed to take advantage of the new flowering plants and animal food sources that became available during the Cretaceous Terrestrial Revolution between 125 and 80 million years ago, the scientists believe.

A computer-generated 'supertree' of dinosaur lineages has helped scientists chart their evolution

The work was carried out using high performance computing facilities at the National University of Ireland at Maynooth.

It was based on a combination of 155 published dinosaur 'trees' and took around 5,000 hours of calculation time.

Professor Mike Benton, from the University of Bristol, said: 'It's not complete, but it's the most detailed and comprehensive single evolutionary tree produced for dinosaurs, and indeed for almost any other group.

'Up until now, most studies of the evolution of dinosaurs were not tested numerically against an accurate and comprehensive database.'


The Cretaceous Terrestrial Revolution was driven by flowering plants and social insects which flourished during this time. They provided a wealth of new food sources for animals, which in turn were eaten by predators.