Publication: The Timetree of life
Editors: S. B. Hedges and S. Kumar
Pages: 177-187

Abstract:

Asterids (over 80,000 species) are grouped into 10 orders and about 100 families. Molecular phylogenetic analyses have supported a phylogeny with a core of euasterids consisting of two main clades: lamiids and campanulids. The order Cornales is the most basal clade in the asterids followed by Ericales as the closest relative of the euasterids. The asterid timetree shows that divergences among the 10 orders occurred in the early Cretaceous, 128–106 million years ago (Ma). A majority of the asterid families evolved before the Cretaceous–Paleogene boundary (66 Ma). These results suggest that continental breakup during the Cretaceous may have influenced the early diversification of asterids.