Dinosaurs became extinct because of an asteroid collision that happened approximately 65 million years ago, and that marked the abrupt end of the Cretaceous period. However, new research carried out by the University of Bristol and NUI Maynooth has proved that dinosaurs 'ran out of evolutionary steam' well before they became extinct.
Academics at NUI Maynooth, part of an international study led by the University of Bristol, have used High Performance Computing facilities to produce a `supertree’ of dinosaurs, showing the most likely pattern of evolution for 440 of the 600 known species of dinosaur. "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”, explained lead author Graeme Lloyd, University of Bristol. “Our supertree summarises the efforts of two decades of research by hundreds of dinosaur workers from across the globe and allows 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 results are published today (23 July) in the Proceedings of the Royal Society B.
Dr Davide Pisani, NUI Maynooth, explained that the supertree “was based on a combination of 155 published dinosaur ‘trees’. The analyses involved are so complex that they could not have been completed using standard computing facilities. Academics at NUI Maynooth are among the European experts in biological computation, and using the High Performance Computing Facilities at the university, the analyses took approximately 5,000 hours of calculation time.”
The new study uses statistical techniques to distinguish unusually high rates of diversification from normal rates. The results show that all the bursts of diversification happened in the first fifty million years of the evolution of dinosaurs. Later expansions were not distinguishable from normal rates. This suggests dinosaurs did not take advantage of the new food supplies available during the Cretaceous Terrestrial Revolution – such as flowering plants, lizards, snakes, birds and mammals.
The key focus was to see whether dinosaurs had been part of a major phase of evolution on land – the Cretaceous Terrestrial Revolution (between 125–80 million years ago) – when many new groups of plants and animals expanded rapidly. During this time, the flowering plants and social insects arose and became more and more common. Many backboned animals also expanded to take advantage of the new sources of food.
For more information contact:
Gibney Communications – (01) 661 0402
Aidan McLaughlin – 085 7490484
NUI Maynooth Communications Dept – (01) 708 3363
Deirdre Watters – (01) 708 3363
NUI Maynooth Biology Dept
Dr Davide Pisani (01) 708 6368
Pdf of the supertree
Dr Davide Pisani