Plant Life on Land • Coal deposits Coals • Coal deposits accumulate in swampy areas – full of organic carbon from plants and animals – need abundant vegetation and reducing environment • vegetation dies, and is buried and preserved instead of oxidized and decayed • compacts to form peat (10:1 ratio) • continued burial and metamorphism produces coal Pennsylvanian Tectonics and Climate Appalachian orogeny • Final suture of Laurasia and Gondwanaland – Himalayan style continent-continent collision – folding and thrusting from Novia Scotia to Florida – persisted into the Permian – Abundant Permian non-marine red beds attest to major period of uplift and erosion – Included belts • Marathon, Ouachita, Blue Ridge, PA Ridge and Valley, New England/Maritime • Overprinted Ca Tectonic Evolution of the Appalachians • higher ground: ‘sphenopsids’ Gymnosperms • In the case of the gymnosperms, • or flowerless seed plants, – these are male and female cones • The male cone produces pollen, – which contains the sperm – and has a waxy coating to prevent desiccation, – while the egg, • or embryonic seed, – is contained in the female cone • After fertilization, – the seed then develops into a mature, cone-bearing plant Glossopteris • Another important non-swamp dweller was Glossopteris, the famous plant so abundant in Gondwana, – whose distribution is cited as critical evidence that the continents have moved through time • at the feet of treelike plants: seed ferns Gymnosperms Free to Migrate • In this way the need for a moist environment – for the gametophyte generation is solved • The significance of this development • is that seed plants, • like reptiles, – were no longer restricted – to wet areas – but were free to migrate – into previously unoccupied dry environments Plants on Higher and Drier Ground • Not all plants were restricted to the coal-forming swamps • Among those plants occupying higher and drier ground were some of the cordaites, – a group of tall gymnosperm trees – that grew up to 50 m – and probably formed vast forests A Cordaite Forest • A cordaite forest from the Late Carboniferous • Cordaites were a group of gymnosperm trees that grew up to 50 m tall Climatic and Geologic Changes • The floras that were abundant – during the Pennsylvanian – persisted into the Permian, – but due to climatic and – geologic changes resulting from tectonic events, – they declined in abundance and importance • By the end of the Permian, – the cordaites became extinct, – while the lycopsids and sphenopsids – were reduced to mostly small, creeping forms Gymnosperms Diversified • Those gymnosperms – with lifestyles more suited to the warmer and drier Permian climates – diversified and came to dominate the Permian, Triassic, and Jurassic landscapes Echinodermata - Crinoidea • Barycrinus hoveyi (Hall) • Early Mississippian, Crawfordsville, Montgomery Co., Indiana • Recrystallized One of the Oldest Known Reptiles • Reconstruction and skeleton of Hylonomus lyelli from the Pennsylvanian Period Paleozoic Reptile Evolution • Evolutionary relationship among the Paleozoic reptiles Late Permian Extinctions • Biggest mass extinction of all time Just before the Mesozoic: Permian\Triassic Extinctions • Many major Paleozoic invertebrate groups extinct • a) Trilobites • b) Rugose and tabulate corals • c) Blastoids • d) Fusulinid foraminifera • e) Brachiopods and crinoids severely reduced The Permian Extinction • Many theories of what caused this extinction have been considered: – The glaciation of Gondwana, the primary theory for the two previous mass extinctions, – the increased fluctuation of global temperatures caused by north and south pole glacier events, – volcanic eruptions occurring in Siberia, flood basalts released huge amounts of CO[2] – The formation of super-continent Pangaea, which possibly caused a reduction of space on the continental shelf. (However, this last theory is especially subject to criticism, because this occurred before the mass extinction did.) – Drop in oxygen content of surface ocean water Which theory is correct? § Maybe all of them. § Maybe none of them. § They all deal with climate changes and changes in the total area that animals could live. § Most likely...a combination of all of them. Ouachita Mobile Belt • Extends from the subsurface of Mississippi to Texas – the Ouachita Mts. and Marathon Mts. are exposed areas of shallow-water clastic and carbonate sediments deformed by compressive forces generated as Gondwana collided with Laurasia