Evolutionary biologists use two ways to study the evolution of prehistoric plants and animals: firstly they use radioactive dating techniques to put fossils in chronological order according to the age of the rocks in which they are found (stratigraphy); secondly they observe and classify the characteristics of fossilised remains according to their relatedness (morphology).
Dr Matthew Wills from the University of Bath’s Department of Biology & Biochemistry worked with Dr Paul Barrett from the Natural History Museum and Julia Heathcote at Birkbeck College (London) to analyse statistical data from fossils of the four major groups of dinosaur to see how closely they matched their trees of evolutionary relatedness.
The researchers found that the fossil record for the dinosaurs studied, ranging from gigantic sauropods to two-legged meat eaters such as T. rex, matched very well with the evolutionary tree, meaning that the current view of evolution of these creatures is very accurate.
Dr Matthew Wills explained: “We have two independent lines of evidence on the history of life: the chronological order of fossils in the rocks, and ‘trees’ of evolutionary relatedness.
“When the two tell the same story, the most likely explanation is that both reflect the truth. When they disagree, and the order of animals on the tree is out of whack with the order in the rocks, you either have a dodgy tree, lots of missing fossils, or both.
“WWhat we’ve shown in this study is that the agreement for dinosaurs is remarkably good, meaning that we can have faith in both our understanding of their evolution, and the relative completeness of their fossil record.