Glumiflorae: Fossil Record

The Glumiflorae have a fossil record dating back to the Cretaceous, though it consists primarily of small fruits and seeds in the early Cenozoic.

The grasses in particular present a difficulty in preservational bias. Because they grow primarily in dry environments, there is not much opportunity for good preservation. Nonetheless, there are many good macrofossils by the Oligocene, with the rise to dominance of grasslands.