Detailed morphological and molecular studies have shown that the group is not actually monophyletic. This makes it easier to reconcile molecular clock data that suggests that the angiosperms diverged from the gymnosperms around .
Some more recent studies have used the word anthophyte to describe a group which includes the angiosperms and a variety of fossils (glossopterids, Pentoxylon, Bennettitales, and Caytonia), but not the Gnetales.