The flowering plants emerged in the
Cretaceous period (see
Geological Time), some 130 million years ago. They dramatically changed the Earth's landscapes, quickly taking over most of the ecological functions.
These fast-growing, adaptable plants also gave rise to a huge boom in the dinosaurs world. Most of the dinosaurs that have been found date from the late Cretaceous period, when flowering plants were supplying plant-eating dinosaurs (like hadrosaurs) with plentiful and nutritious food.
Some Mesozoic Era angiosperms included magnolias, laurel, barberry, early sycamores, and palms. Grasses may have evolved later. Cretaceous vegetation was increasing in density and species diversity as the quick-to-adapt flowering plants radiated throughout the world.
The Magnolia flower shows many features of the earliest flowers. Spirally arranged microsporophylls (anthers) and megasporophylls (carpels) are surrounded by non-spore-bearing leaves (petals and sepals which together are termed the perianth).
The earliest pollinators were just beetles chomping their way through flowers, accidentally spreading pollen and, in view of the bounty of flower parts, sparing some carpels to form seed and fruit. The insects and flowers co-evolved causing the flower structure and insect mouth parts to evolve.