Most people cannot imagine a world without grass. However, grass is actually relatively new to the world and it is thought that without grass, there would be no humans. The logic is that grass contained more energy than previous plants, allowing for the evolution of large grazing animals that served as the food source for early humans. If you wanted to make a real Jurassic Park, you definitely wouldn't include grass because it is younger than the dinosaurs of the Jurassic by almost 80 million years!
