ABSTRACT
The documentation of derived angiosperm lineages from increasingly older geological deposits, and growing evidence of considerable diversity in flower, seed, and pollen morphology in the mid-Cretaceous both imply that the timing of early angiosperm cladogenesis may be older than our current fossil-based estimates indicate. An alternative to fossils for calibrating the phylogenetic tree comes from divergence in DNA sequence data. Here, we report on an analysis using nonparametric rate smoothing and a three gene dataset covering c. 75 per cent of all angiosperm families recognized in recent classifications. The results provide an initial hypothesis of angiosperm diversification times; by using an internal calibration point, an independent evaluation of angiosperm and eudicot origins is accomplished. Results are compared with fossil-based estimates of both magnolids and eudicot divergence times, and possible directions of future analyses are discussed.
