The Late Paleozoic World Chapter 15 The Late Paleozoic World

Guiding Questions How did marine life of late Paleozoic time differ from that of middle Paleozoic time? How did terrestrial floras change on a global scale in late Paleozoic time? What changes occurred in terrestrial faunas during late Paleozoic time? What major biotic changes occurred in the latter part of Permian time?

251 Million years 299 Million years 318 Million years 359 Million years

Late Paleozoic Carboniferous glaciation Abundant swamps Permian drying

Late Paleozoic Life in the Sea Marine Ammonoids abundant Highly mobile Brachiopods Productids Cone-shaped shells Produced reefs

Late Paleozoic Life in the Sea Crinoid meadows Significant contribution to early Carboniferous (Mississippean) limestone

Late Paleozoic Life in the Sea Bryozoans Sheetlike colonial animals Trapped sediment in mounds Important contribution to limestone

Late Paleozoic Life in the Sea Fusulinids Foraminifera Late Carboniferous radiation Up to 10 cm in length Guide fossil for Upper Carboniferous and Permian

Late Paleozoic Life in the Sea Higher Mg-Ca ratio Aragonitic algae Important in late Carboniferous reefs Aragonitic sponges Play important role in Permian reefs

Late Paleozoic Life on Land Extensive swamps developed Coal swamps dominated by lycopods Lepidodendron Up to 30 m tall Sigillaria

Late Paleozoic Life on Land Seed ferns Abundant Small bushy plants Large and treelike Glossopteris

Late Paleozoic Life on Land Sphenopsids Not found in coal swamps Levees and floodplains

Late Paleozoic Life on Land Cordaites Upland plants Gymnosperms Naked seed plants Formed woodlands Conifers Cone bearing plants

Late Paleozoic Life on Land Permian Gymnosperms came to dominate terrestrial environments

Late Paleozoic Life on Land Winged insects Dragonflies Mayflies

Late Paleozoic Life on Land Amphibians Reptiles

Late Paleozoic Life on Land Reptiles Requires amniote egg Protects embryo No longer needs water for development Pelycosaurs Dimetredon Eryops

Late Paleozoic Life on Land Therapsids Similar to mammals Legs no longer sprawling Complex jaws Endothermic Warm-blooded Ectothermic Cold-blooded

Late Paleozoic Paleogeography Continents clustered near each other Early Carboniferous High sea level Warm, shallow seas Abundant limestone Evaporites on western North American continent

Late Paleozoic Paleogeography Mid-carboniferous Mississippian Pennsylvanian Gondwanaland collided with Eurasia (Hercynian) Extended Appalachians Alleghenian mountains Formed Ouachita Belt Oklahoma, Texas Glaciers; Sea level drops Later Carboniferous Increased latitudinal gradients Glaciation expanded

Late Paleozoic Paleogeography Permian Pangaea nearly complete Ural Mountains Interior Low moisture Evaporites and dunes Reduced carbon burial Led to higher atmospheric CO2 Global warming ended glaciation

Late Paleozoic Paleogeography Western dunes

Alleghenian Orogeny Mountain building shifted to Eastern US Valley and Ridge Thrust faults Blue Ridge Grenville age rocks

Alleghenian Orogeny Continued molasse deposition

Southwestern U.S. Ouachita Mountains Westward continuation of Appalachians Fold and thrust belt of offshore deposits

Southwestern U.S. Microplates also accreted to Central America

Fountain Arkose Eastern flank of Front Range

Cyclothems and Coal Cycles in coal beds that contain marine sediments Slight change in sea level Alternating transgressions and regressions

Cyclothems and Coal Transgression Deposition of marginal marine peat on top of nonmarine deposits Capped with marine sediments

Cyclothems and Coal Regression Reversed the sequence Oscillating glaciers led to changes in sea level

Delaware Basin In Texas and New Mexico Economically important

Delaware Basin Only flooded region in Permian Significant petroleum source Midland Basin Filled with sediment

Delaware Basin Delaware Basin Capitan Limestone Carbonate and evaporite deposition Reef grew upward Waters receded and stranded reef Capitan Limestone

Delaware Basin Early on, benthic organisms received oxygen When basin deepened, bottom waters deepened, stagnated

Glacial Striations South Africa

Fossil Wood Antarctic Wood Growth was interrupted in winter

Late Paleozoic Unconformity Global unconformity in marine sediments

Late Phanerozoic Life Rates of Origination and Extinction

Late Permian Anoxia Japan Uplifted rocks Gray chert replaced oxidized hematite

Carbon Isotope Ratios Negative shift at Permian/Triassic boundary