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. [24] The climate would have affected the dominant organisms in reefs; microbes would have been the main reef-forming organisms in warm periods, with corals and stromatoporoid sponges taking the dominant role in cooler times. Here we see two different tetrapod protoamphibians, oneAcanthostegaand twoIcthyostegain a pool along with three lungfish (Dipterus) and a placoderm (Bothriolepis). Some brachiopods are long and thin such asMucrospirifer grabau,or the three specimens ofMucrospirifer prolificus. This may have contributed to the cooling climate and the extinction event at the end of the Devonian. During the Devonian, Asia was composed of many separate microplates that are now joined together. It was during the Devonian period that the temperate regions of the earth's evolving continents first became truly green. There were three major extinctions during the last half of the Devonian Period, each separated by about ten million years. The close of the Devonian Period is considered to be the second of the "big five" mass extinction events of Earth's history. A number of small specimens are housed in this case: Echinoderms(ToL: Echinodermata Where Is The Transponder Number On Sunpass Pro,
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