Fossil calibrations, a relative clade age calibration (informed by horizontal gene transfer) and new phylogenomic methods for mapping gene family origins resolve tracheophytes (vascular plants) and bryophytes (non-vascular plants) as monophyletic sister groups that diverged during the Cambrian, 515–494 million years ago. The early evolution of both groups, but particularly that of bryophytes, was characterized by major gene content change.
- Brogan J. Harris
- James W. Clark
- Tom A. Williams