Permian Greg Daviduck & Alex Dreger
The Permian Time Period The Permian is a geologic period and system characterized among land vertebrates by the diversification of the early amniotes into the ancestral groups of the mammals, turtles, lepidosaurs and archosaurs. It is the last period of the Paleozoic Era and famous for its ending epoch event the largest mass extinction known to science. The Permian Period was named after the kingdom of Permia in modern-day Russia by Scottish geologist Roderick Murchison in 1841.
Landforms & Continent position • Deserts seem to have been widespread on Pangea. Such dry conditions favored gymnosperms, plants with seeds enclosed in a protective cover, over plants such as ferns that disperse spores. The first modern trees appeared in the Permian. During the Permian, all the Earth's major land masses except portions of East Asia were collected into a single supercontinent known as Pangea. Pangea straddled the equator and extended toward the poles, with a corresponding effect on ocean currents in the single great ocean.
Major Distinctive Events The Cimmeria continent rifted away from Gondwana and drifted north to Laurasia, causing the Paleo-Tethys to shrink. A new ocean was growing on its southern end, the Tethys Ocean, an ocean that would dominate much of the Mesozoic Era. Three general areas are especially noted for their extensive Permian deposits - the Ural Mountains (where Perm itself is located), China, and the southwest of North America, where the Permian Basin in the U.S. state of Texas is so named because it has one of the thickest deposits of Permian rocks in the world.
Permian Mass Extinction The Permian ended with the most extensive extinction event recorded in paleontology: the Permian-Triassic extinction event. 90% to 95% of marine species became extinct, as well as 70% of all land organisms. It is also the only known mass extinction of insects.On an individual level, perhaps as many as 99.5% of separate organisms died as a result of the event. Recovery from the Permian-Triassic extinction event was protracted; on land ecosystems took 30M years to recover. There is also significant evidence that massive flood basalt eruptions from magma output lasting thousands of years in what is now the Siberian Traps contributed to environmental stress leading to mass extinction.
Climate • As the Permian opened, the Earth was still in the grip of an ice age, so the polar regions were covered with deep layers of ice. Glaciers continued to cover much of Gondwanaland (one of the continents of Pangea), as they had during the late Carboniferous. At the same time the tropics were covered in swampy forests. • Towards the middle of the period the climate became warmer and milder, the glaciers receded, and the continental interiors became drier. Much of the interior of Pangea was probably arid, with great seasonal fluctuations (wet and dry seasons), because of the lack of the moderating effect of nearby bodies of water. This drying tendency continued through to the late Permian, along with alternating warming and cooling periods.
Corals Coral is a marine organism that is made up of millions of smaller genetically identical polyps They secrete calcium carbonate to for a hard exoskeleton Most corals depend on sunlight therefore they tend to grow in shallow water and often bond together to form reefs
Trilobites Trilobites are hard shelled, segmented creatures that lived between The Cambrian period and survived up to the Permian period Trilobites were widely spread their fossils are found across every continent in the world
Gastropods Gastropods were the largest and the most successful of the molluscs classes They have developed aggressive eating mechanism and pulmonary system The early Gastropods had spiral shells that resembled a curled garden hose
Belemnites Belemnites were squid-like carnivores with a soft body around an internal, pencil-shaped shell The cuttlefish is the modern-day relative of the belemnite Belemnites were efficient carnivores that caught small fish and marine animals with their tentacles, and ate them with their beak-like jaws Their tentacles were different to the modern squid, as they had hooks instead of suckers to grab prey They were built for speed and probably lived in shoals and fossil evidence shows they formed a major part of the diet of ichthyosaurs.
Bivalves A mollusk, such as an oyster or a clam, that has a shell consisting of two hinged valves Bivalves have no head. They feed on phytoplankton by pumping water across the gills and trapping food particles that are then moved to the mouth
Crinoids Superficially, these crinoids resemble plants, what with there fronds, stems, and roots anchoring them to the rocks. Yet crinoids are animals, organisms with a nervous system, and the larvae are capable of swimming freely before metamorphosing to the sessile form seen in this photo.
Brachiops Brachiopods make up one of the major animal types. Also known as lamp shells, they are sessile, two-shelled, marine animals that somewhat resemble "clams" externally but are quite different internally. Unlike bivalves, which have a left shell and a right shell, brachiopods are always bilaterally symmetric, although the top and bottom shells usually differ in shape.
Insects By the Pennsylvanian and well into the Permian, by far the most successful were primitive relatives of cockroaches. Six fast legs, two well developed folding wings, fairly good eyes, long, well developed antennae (olfactory), an omnivorous digestive system, a receptacle for storing sperm, a chitin skeleton that could support and protect, as well as form of gizzard and efficient mouth parts, gave it formidable advantages over other herbivorous animals. About 90% of insects were cockroach-like insects
AMPHIBIANS AND REPTILES • Early Permian terrestrial faunas were dominated by pelycosaurs and amphibians, the middle Permian by primitive therapsids such as the dinocephalia, and the late Permian by more advanced therapsids such as gorgonopsians and dicynodonts. Towards the very end of the Permian the first archosaurs appeared, a group that would give rise to the dinosaurs in the following period. Also appearing at the end of the Permian were the first cynodonts, which would go on to evolve into mammals during the Triassic. Another group of therapsids, the therocephalians (such as Trochosaurus), arose in the Middle Permian. There were no aerial vertebrates.
Ferns and Conifers • At the beginning of the Permian Period, ferns and seed-ferns were the dominant plant life. As the climate grew drier, these simpler plants were replaced by more complex plants, such as conifers and ginkgoes.
Bibliography • http://en.wikipedia.org/wiki/Permian/ • http://www.fossilbase.org/index.php?pageid=beginner • http://www.abc.net.au/dinosaurs/fact_files/sea/sealife/belemnite.htm • http://www.manandmollusc.net/advanced_introduction/moll101gastropoda.html • http://www.trilobites.info/trilobite.htm • www.mnh.si.edu/LivingFossils/crinoid1.htm