Earth history; Permian

Click on a fossl Micromelerpeton credueri Branchiosaurus sp. Discosauriscus sp. Macroleter piesicus Permian
The world map shows Pangaea, which is the name of the super-continent stretching from pole to pole. Long distances to the sea lead to a change in the climate and widespread deserts. A group of four-legged vertebrates, independent of periodical water dwelling, appeared. They had developed a new type of egg, which could be lain on dry land; with a hard shell and nourishment for the fetus both in the yolk and the egg white. The bones in the neck and foot made it possible for the animals to lift their heads and walk more efficiently. These animals could walk long distances into Pangaea; they were no longer amphibians, but reptiles. Towards the end of the period, large mammal-like reptiles spread across the continent. A fall in the sea-level lead to a reduction in the size of the shallow-sea environments, thus leading to the total extinction of all trilobites, tabulate corals and rugose corals. Large groups of bryozoans, brachiopods, sponges and crinoids, also vanished. 
List of contents in the Earth history; Permian showcase

Klikk på en tidsperiode Prekambrium Kambrium Ordovicium Silur Devon Karbon Perm Kvartær Trias Jura Kritt Tertiær
[Norsk tekst]
Publisert 18. mai 2011 16:00 - Sist endret 13. mai 2019 13:56