Grass
Grasses include some of the most versatile plant life-forms. They became widespread toward the end of the Cretaceous. Fossilized dinosaur dung (coprolites) have been found containing  grass phytoliths (silica stones inside grass leaves). Grasses have adapted to conditions in lush rain forests, dry deserts, cold mountains and even intertidal habitats, and are now the most widespread plant type. Grass is a valuable source of food and energy for many animals.