Can anyone tell me what foods the plant-eating dinosaurs had at the end of the Cretaceous?

Tall ginkgo, ferns, cycads and conifers, these plants are the favorite food of herbivorous dinosaurs

There are also coniferous plants and early angiosperms, but Herbs do not play a major role among them. The reason is that the teeth of herbivorous dinosaurs are sparse and cannot grind grass stems like the teeth of mammals.