The Permian Mass Extinction
- Permian Period (286-248
million years ago)
- Terrestrial faunal diversification occurred in the
- 90-95% of marine species became extinct in the Permian
With the formation of the super-continent Pangea in the Permian, most of the Earth's land area became contiguous.
The result of this new configuration was the extensive development and diversification of Permian terrestrial vertebrate fauna. This was accompanied by a reduction of Permian marine communities which once inhabited the epicontinental seas, now dry. Among terrestrial fauna affected included insects, amphibians, reptiles (which evolved during the Carboniferous), as well as the dominant terrestrial group, the therapsids (mammal-like reptiles). The terrestrial flora was predominantly composed of gymnosperms, including the conifers. Life in the seas was similar to that found in middle Devonian communities following the late Devonian crisis. Common groups included the brachiopods, ammonoids, gastropods, crinoids, bony fish, sharks, and fusulinid foraminifera. Corals and trilobites were also present, but were exceedingly rare.
The Permian mass extinction occurred about 248 million years ago and was the greatest mass extinction ever recorded in earth history; even larger than the previously discussed Ordovician and Devonian crises and the better known End Cretaceous extinction that felled the dinosaurs. Ninety to ninety-five percent of marine species were eliminated as a result of this Permian event. The primary marine and terrestrial victims included the fusulinid foraminifera, trilobites,rugose and tabulate corals, blastoids, acanthodians, placoderms, and pelycosaurs, which did not survive beyond the Permian boundary. Other groups that were substantially reduced included the bryozoans, brachiopods, ammonoids, sharks, bony fish, crinoids, eurypterids, ostracodes, and echinoderms.
Causes of the Permian Extinction
Mass Extinctions of the Phanerozoic Menu