Editor's Summary

29 March 2007

The long hello


Did modern-style mammals evolve in a huge burst after the non-avian dinosaurs became extinct 65 million years ago, or did they take longer to assume modern forms? The debate rumbles on, with palaeontologists generally favouring a short-fuse 'burst' model, and molecular phylogeneticists suggesting that mammals had much deeper roots. Bininda-Emonds et al. have used a massive set of molecular data to show that not only did mammalian evolution have deep roots, but that the extant Orders of mammals did not become established until many millions of years after the dinosaurs had gone. And the mass extinction at the end of the Cretaceous had little discernible effect on mammalian evolution.

News and ViewsEvolutionary biology: Mass survivals

The conclusion that the primary divergences of the modern groups of mammals occurred in the mid-Cretaceous requires fresh thinking about this facet of evolutionary history — especially in ecological terms.

David Penny & Matthew J. Phillips

doi:10.1038/446501a

ArticleThe delayed rise of present-day mammals

Olaf R. P. Bininda-Emonds, Marcel Cardillo, Kate E. Jones, Ross D. E. MacPhee, Robin M. D. Beck, Richard Grenyer, Samantha A. Price, Rutger A. Vos, John L. Gittleman & Andy Purvis

doi:10.1038/nature05634