Australia: The Land Where Time Began

A biography of the Australian continent 

Extant Phylogenetic Bracket (EPB)

As crocodiles evolved before dinosaurs and birds evolved after the evolution of dinosaurs, dinosaurs a situated on the phylogenetic tree between living crocodiles and living birds.

Based on this relationship any anatomical features that are present in both birds and crocodiles should be present in dinosaurs because of the bracketing in the line of evolution from crocodile-dinosaur-bird. This has been used at time to help deduce biological features among extinct groups when clear evidence of these features is lacking, though it is cautioned that this method should be used carefully as dinosaurs could be very specialised when compared to living birds and crocodiles, as is the case of the hand of Iguanodon.

Sources & Further reading

1. Norman, David, 2005, Dinosaurs: A Very Short Introduction, Oxford University Press