The Devonian Period comprises the years between 416 million and 354 million and is subdivided by periods: Lower (the oldest), Middle and Upper (the most recent).
During this period, the main transformations occurred in the flora, with the exponential growth of small terrestrial plants through the development of spores. With this process, plants will become more similar with modern plants. During this period the plants were able to fertilize themselves with the seeds and reach the height of trees. They formed the first forests to be recorded, with the appearance of licopodia, ferns and progimosperms.
