While the diversification of fishes is exciting, the Devonian vascular plant explosion is even more spectacular. Some species were capable of breathing air through spiracles in the skull. The earliest-known trees appeared in the Middle Devonian. The oceans experienced episodes of reduced dissolved oxygen levels, which likely caused the extinction of many species, especially marine animals. The first significant adaptive radiation of life on dry land occurred during the Devonian. As the Caledonian Orogeny wound down in the later part of the period, orogenic collapse facilitated a cluster of granite intrusions in Scotland. Invertebrate land animals such as scorpions, spiders, and wingless insects also began to thrive in the new environments created by the vascular plant explosion. The majority of the fish present nowadays belong to the bony fish group. Kazakhstania was a volcanically active region during the Devonian, as it continued to assimilate smaller island arcs. It was the fourth period of the Paleozoic Era. Two specimens are displayed to show some of the distinctive internal anatomy, including the coiled lophophore supporting structure of the brachiopodParaspirifer bownockeri: click on the engraving to compare our specimens with known aspects of brachiopod anatomy. It was typically characterized by dominance of fish species and the appearance of amphibians on the planet for the first time. This is the last in a 10-part series arguing that fossils record the Earth's recolonisation after a mass extinction near the very beginning of history. They were also void of vascular tissues and were only a few centimeters tall. The study's authors instead attribute the increased overall diversity of nekton in the Devonian to a broader, gradual trend of nektonic diversification across the entire Palaeozoic. NASA warns of 3 skyscraper-sized asteroids headed toward Earth this week. Two specimens ofPseudoatrypa devoniana, shown from different viewpoints, are excellent examples of pyrite replacement, Moss Animals (ToL: Bryozoa