Modern "savannahs", "steppes", and "pampas" are widely distributed as biomes and are open, relatively flat spaces, covered with a green carpet of plants with few trees and shrubs. These biomes are primarily composed of what we simply call "grass", most of which, from a biological point of view, is grasses. Grasses are fast-growing herbaceous flowering plants with characteristic fruits - spikelets. The first grasses appear in nature about 66-23 million years ago, at the end of the Paleogene period, and the real savannahs began to spread around the world approximately 23-2.6 million years ago, in the Neogene period.

"Cretaceous savannahs", "steppes", and "pampas" existed in the form of vast plains, where specific types of grass prevailed, different from those we see today. The main herbaceous plants of that time were ferns, not the familiar "lawn grasses". Horsetails, clubmosses, and even some of the earliest flowering plants were also widespread at that time. However, ferns were domi...