Species cannot coexist without competition if they try to occupy the same niche. The geological period that lasted from 280 Ma ago to 225 Ma ago. At the end of this period the largest mass extiction ever to hit life on Earth occured. The period is named for the province of Perm in Russia. Nearly all forms of life are either direct consumers of plants or eat the flesh of herbivores, so without photosynthesis there would e little or no life on Earth.
Photosynthesis also supplies nearly all the oxygen in the atmosphere, another vital role of plants.
The part of the geological record that exists before 570 Ma. Green plants are primary producers, because they are the lowest link in the food chain. These terms refer to events during which a single species gives rise to many other species. The flowering plants are a good example of this, as are the dinosaurs. These events often happen after mass extinction events, but not always.