Devonian Time Span Date range: 419.2 million years ago to 358.9 million years ago Length: 60.3 million years (1.3% of geologic time) Geologic calendar: November 28 (6 PM)-December 3 (1 PM) (4 days, 19 hours) Devonian age fossil brachiopod, Death Valley National Park, California and Nevada. During the Devonian a few freshwater fish began the transition to life on land. What year did the Ordovician period start and end? The tectonic effects of this collision continued into the Devonian, producing a string of mountain ranges along the southeastern coast of the continent. Warm and equable climates were common, as shown by the wide distribution of evaporite basins in the Northern Hemisphere, by coal deposits in Arctic Canada and Spitsbergen, and by widespread desert conditions and carbonate reefs. Another common term is "Age of the Fishes",[20] referring to the evolution of several major groups of fish that took place during the period. Although con-odont survivorship is comparable to survi-z-o-CS z ul u Cu w IL 'C 1-50 75 100 125 150 my [24] Reconstruction of tropical sea surface temperature from conodont apatite implies an average value of 30C (86F) in the Early Devonian. Live Science is part of Future US Inc, an international media group and leading digital publisher. Lily-like crinoids (animals, their resemblance to flowers notwithstanding) were abundant, and trilobites were still fairly common. The Hangeberg Event at the Devonian/Carboniferous Boundary killed the Placoderms and most of the early ammonites. The Devonian Period was an interval of the ancient Paleozoic Era spanning from about 419.2 million years ago to 358.9 million years ago, according to Britannica. Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. Let us know if you have suggestions to improve this article (requires login). [25][26], The Devonian world involved many continents and ocean basins of various sizes. The Middle Devonian comprised two subdivisions: first the Eifelian, which then gave way to the Givetian 387.70.8million years ago. Complex soils were formed, land and water linkages were expanded, habitats became more complex and stable, and organic matter increased both on land and in the oceans though runoff. Invertebrate land animals such as scorpions, spiders, and wingless insects also began to thrive in the new environments created by the vascular plant explosion. There were three major extinctions during the last half of the Devonian Period, each separated by about ten million years. Our editors will review what youve submitted and determine whether to revise the article. 10. These continental blocks, collectively known as the Armorican Terrane Assemblage, split away from Gondwana in the Silurian and drifted towards Laurussia through the Devonian. Sponges (ToL: Porifera