Relative newcomers in Earth history, flowering plants, or angiosperms, first appeared about 130 million years ago in the Early Cretaceous. They reproduced via seeds, sprouted and grew quickly, and lured insects to transfer pollen among plants. By the Late Cretaceous, many flowering plants were thriving in a range of habitats, sharing space with conifers, ferns, and increasingly rare cycads. Today, angiosperms account for 90 percent of plant species—including all the grains, fruits, and vegetables we enjoy. Duck-billed hadrosaurs, like this trio of Edmontosaurus, diversified and adapted so they could eat the Late Cretaceous’s botanical bounty. The dinosaur and plant fossils shown here date to nearly the peak of the dinosaurs’ reign.

The hadrosaur Edmontosaurus annectens was the cow of the Cretaceous: it had hooves, lived in herds, and grazed. Its hundreds of stacked, continuously growing teeth and unique chewing motion helped it grind up tough vegetation.

This fossilized flowering-plant leaf from the Hell Creek Formation shows new features: a tapering “drip tip,” plus veins that could carry lots of water into the plant’s tissues and promote swift growth.

Smaller ornithopods probably ate different plants than hulking hadrosaurs did. This specimen of Thescelosaurus neglectus shows fossilized cartilage on its ribs and tendons across its backbone.

Today represented by laurel and cinnamon, the Laurales order included this Late Cretaceous flowering plant.