The earliest known tetrapod is Tiktaalik roseae. For example, during the Early Devonian, arid conditions were prevalent through much of the world including Siberia, Australia, North America, and China, but Africa and South America had a warm temperate climate. About 20% of all animal families and three-quarters of all . Like the other periods of the Palaeozoic, the Devonian was first defined in the 1830s. Economic significance of Devonian deposits, Major subdivisions of the Devonian System, Occurrence and distribution of Devonian deposits, A Journey Through Time Since the Precambrian, https://www.britannica.com/science/Devonian-Period, National Park Service - Devonian Period419.2 to 358.9 mya, Public Broadcasting Service - Devonian Period. In the 1930s, oil was found in Devonian sandstones in the Ural-Volga region and later in the Pechora area of northern European Russia. It was preceded by the Silurian Period and followed by the. Eventually, by the later Permian Period, this drift would lead to collision with the equatorial continent known as Euramerica, forming Pangaea. Devonian Period, in geologic time, an interval of the Paleozoic Era that follows the Silurian Period and precedes the Carboniferous Period, spanning between about 419.2 million and 358.9 million years ago. The distribution of nonmarine fish and marine invertebrate fossils demonstrates that Europe, Siberia, and the Canadian Arctic islands were linked and formed the bulk of Laurussia. Let us know if you have suggestions to improve this article (requires login). Life was primitive during the Paleozoic and included many invertebrates (animals without backbones) and the earliest fish and amphibians. The Devonian Period is the fourth period of the Paleozoic Era. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. Devonian reefs also extended along the southeast edge of Laurussia, a coastline now corresponding to southern England, Belgium, and other mid-latitude areas of Europe. * The Devonian was named for strata in Devon, England by Sedgewick and Murchison in 1839. The eastern branch of the Paleo-Tethys was fully opened when South China and Annamia (a terrane equivalent to most of Indochina), together as a unified continent, detached from the northeastern sector of Gondwana. The earliest plants on the planet had no roots or leaves. Amongst the severely affected marine groups were the brachiopods, trilobites, ammonites, and acritarchs, and the world saw the disappearance of an estimated 96% of vertebrates like conodonts and bony fishes, and all of the ostracoderms and placoderms. Their collision with Laurussia leads to the beginning of the Variscan Orogeny, a major mountain-building event which would escalate further in the Late Paleozoic. They are among the earliest known vascular plants. Species that survived multiplied and diversified, the land was progressively reconstituted, and its repeatedly disturbed and buried surfaces were revegetated. Please refer to the appropriate style manual or other sources if you have any questions. Siberia approached the eastern edge of Laurussia as the Devonian progressed, but it was still separated by a seaway, the Ural Ocean. The oceans experienced episodes of reduced dissolved oxygen levels, which likely caused the extinction of many species, especially marine animals. These south polar seas hosted a distinctive brachiopod fauna, the Malvinokaffric Realm, which extended eastward to marginal areas now equivalent to South Africa and Antarctica. It had a softwood trunk similar to modern conifers that grew in sequential rings. The first tetrapods appeared in the fossil record in the ensuing Famennian subdivision, the beginning and end of which are marked with extinction events. Details of the anatomy of this early plant are shown in the macrophotos: image showing spines (right edge of stem) and central tracheal element (center of stem, upper half). [57][60] Land plants as well as freshwater species, such as our tetrapod ancestors, were relatively unaffected by the Late Devonian extinction event (there is a counterargument that the Devonian extinctions nearly wiped out the tetrapods[61]). This period started about 419 million years ago and ended 358.9 million years ago. These features made them effective hunters, and they survived for millions of years. Unauthorized use is prohibited. Fish (ToL: Vertebrata