A fossil-calibrated molecular clock estimates a middle Cambrian–Early Ordovician origin for crown land plants; it does not directly date fossil first appearances or terrestrial ecosystem expansion.
Represented range515–473 Ma
RegionsGlobal molecular-clock sample
CladesEmbryophyta
Claim ledger
divergence-time · medium
Bayesian relaxed-clock analyses using 37 fossil calibrations estimate crown Embryophyta to have emerged in a middle Cambrian–Early Ordovician interval, before crown tracheophytes in the Late Ordovician–Silurian; these are modelled divergence times, not direct fossil first appearances.