Until recently, fossil findings indicated that grasses evolved around 55 million years ago.
At 35 Ma, grasses evolved from among the angiosperms.
While this time period boasts many types of plants, grass had not yet evolved.
Rick was starting to explain how grass, and therefore grain, had not yet evolved when Joe cut him short with a sharp look.
One of the problems was that they had to find areas that had no grass, since grasses evolved after the dinosaurs had disappeared.
Their diet would have consisted of leaved plants or fruits, as grasses did not evolve until after Scelidosaurus had become extinct.
The grass simply evolves into underwater grass and seems to exist equally comfortably waving dreamily around, endlessly drowning.
That is, the grasses hadn't yet evolved to the point of forming solid carpets over all the open ground.
True grasses have evolved to become highly specialised for wind pollination.
You say that you plan on going back to a time when grass has evolved.