GEOLOGY

Detailed explanation-1: -By the end of the Devonian, ferns, horsetails and seed plants had also appeared, producing the first trees and the first forests. At left, the fern-like leaves of Archaeopteris, one of the first tree-like plants. It grew to an average height of about 10 meters, produced spores, and had a global distribution.

Detailed explanation-2: -Toward the end of the Devonian the first forests arose as stemmed plants evolved strong, woody structures capable of supporting raised branches and leaves. Some Devonian trees are known to have grown 100 feet (30 meters) tall. By the end of the period the first ferns, horsetails, and seed plants had also appeared.

Detailed explanation-3: -During the Devonian Period, which occured in the Paleozoic era, the first fish evolved legs and started to walk on land as tetrapods, and the first arthropods like insects and spiders also started to colonize terrestrial habitats. The first seed-bearing plants spread across dry land, forming huge forests.

Detailed explanation-4: -A second mass extinction called the Hangenberg event, also known as the end-Devonian extinction, occurred 359 million years ago, bringing an end to the Famennian and Devonian, as the world transitioned into the Carboniferous Period.