Prehistoric plants include mosses, horsetails and ferns from the Paleozoic era and bald cypress, ginkgos, cycads, magnolias and palms from the Mesozoic era. Horsetails and ferns are considered to be the first land plants. Scientists believe their spores created new plants and led the way to gymnosperms. Flowering plants were the last to appear and are now the most prevalent species on the planet.
Scientists and archaeologists have been able to study plant fossils left behind when portions of the plants, such as the stems, leaves, roots, spores, seeds or fruits, became trapped within volcanic ash, clay, mud or sand. This transpiration preserved the plants and protected them from certain elements that would normally have caused their remnants to decompose over time.
Plants appeared on the Earth far earlier than animals did. Scientists believe that the presence of plants is precisely what made the existence of animals possible in later prehistoric eras. Plants released vital oxygen into the atmosphere as a by-product of their process of photosynthesis, and this manifestation prepared an environment that was suitable for animals to develop and flourish. Plants acted as a food source for most animals in the earliest eras, and they continue to form the foundation for food chains in the modern age.