Flowering plant origins

An oak, a rose and a grass are all flowering plants. When did the last common ancestor of all living flowering plants live? Its descendants form the group being dated; this is not simply the date of the oldest known fossil or the first flower.[1] [2] [3]

All living branches of flowering plants, including grasses and oaks, trace back to their last common ancestor. When did it live? Dating that crown group requires distinguishing it from the earlier lineage leading to the ancestor, called the stem lineage, and from the first flower. Molecular clocks combine DNA change with fossil constraints because genetic differences alone do not separate time from changing rates of evolution. Fossil placement, missing sampling and model assumptions therefore matter. A 2025 analysis favored a largely Triassic crown age; a 2026 integration favored the younger latest Jurassic. Their different ways of using fossils leave a disagreement, not a final date.[1] [2] [3]

Recent fossil-and-DNA analyses favor different times.[1] [2]

The 2025 fossilized birth–death approach and 2026 fossil-calibration integration produce conflicting estimates. Neither is treated as final consensus.[1] [2]

These plants transformed land ecosystems. The age of their shared ancestor changes how much time their lineages had to diversify before the widespread flowering-plant ecosystems seen later in the fossil record.[3]

The age constrains how much time the living lineages had to diversify and interact with other organisms. It also tests how reliably incomplete fossils and present-day DNA can reconstruct ancient ecological transformations.[1] [3]