In a suitable environment the seed coat ruptures and the embryo emerges as a seedling, using the food stored in the endosperm and cotyledons. The Rise of Angiosperms Angiosperms showed a relatively sudden appearance in the fossil record with no clear transitional links to ancestors. Angiosperms perhaps evolved from seed ferns, an extinct group of unspecialized gymnosperms. E. Relationships Between Angiosperms and Animals Terrestrial plants and animals have coevolved - a consequence of their interdependence. For example, Coevolution between angiosperms and their pollinators led to diversity of flowers.
Some pollinators are specific for a particular flower.
The pollinator has a monopoly on a food source and guarantees the flower's pollen will pollinate a flower of the same species.