Moore MJ, Soltis PS, Bell CD, Burleigh JG, Soltis DE. 2010. Phylogenetic analysis of 83 plastid genes further resolves the early diversification of eudicots. Proceedings of the National Academy of Sciences USA 107(10):4623-8This is an Open Access article.
Phylogenetic analyses of 83 protein-coding and rRNA genes from the plastid genome for 86 species of seed plants, including new sequences from 25 eudicots, indicate that soon after its origin, Pentapetalae diverged into three clades... Molecular dating analyses suggest that the major lineages within both superrosids and superasterids arose in as little as 5 million years. This phylogenetic hypothesis provides a crucial historical framework for future studies aimed at elucidating the underlying causes of the morphological and species diversity in Pentapetalae.