Dinosaurs ran out of stamina in the evolutionary race

Published on Tuesday 22 July 2008 22:06

DINOSAURS were running out of evolutionary steam during their last 50 million years on Earth, scientists have learned.

The reptiles were left behind in the "Cretaceous Terrestrial Revolution", 100 million years ago, that saw the massive proliferation of vegetation and many animals.

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

Researchers made the discovery after using computer programs to produce a "super-tree" of dinosaur lineages. The results showed the most likely pattern of evolution for 440 of the 600 known species of dinosaur.

The findings, published in the journal Proceedings of the Royal Society B, reveal dinosaurs had a burst of diversification in the first 50 million years of their reign. Then their rate of evolution slowed down and scientists believe they failed to take advantage of the new plant and animal food sources.