Late Paleozoic
Significant climatic changes: glaciation then drying and increased aridity
Seed plants and mammal-like reptiles dominated
Formation of most of Pangea
Includes:
Carboniferous Period coal from newly evolved plants
Mississippian named for limestone exposures along the Mississippi
Pennsylvanian named for coals in Pennsylvania
Permian Period greatest mass extinction of all Phanerozoic
time
Named for rock exposures in Perm, Russia
Marine Life
Similar to that in the Devonian, with the exception of new reef building organisms
Tabulate corals and stromatoporoids never again dominated after the Late Devonian, aragonite versus calcite seas
Armored placoderm fish extinct shortly after start of the Carboniferous
Trend was to go from heavily armored slow forms to fast swimming predator forms without armor (light ammonoids, sharks, and ray-finned fish)
Little is known of algae and phytoplankton due to poor fossil record
Productid brachiopods anchored with spines, dominant on many reefs
Crinoids reached their zenith in the Carboniferous
Lacy bryozoans lophophore filter feeding structure, related closely to brachiopods
Fusilinids single-celled foraminifera, up to 10 cm in length
Aragonite algae built large reefs Walsortian Mounds
Terrestrial Life
Significantly different from the Devonian
New insects and spore trees in the Mississippian, replaced by seed trees in the Permian
Coal deposits developed in lowland swamps, wetlands much more extensive than today
Dominant coal swamp flora:
Lycopods spore plants up to 30 m tall and 1 m diameter trunks
Lepidodendron
Sigillaria
Seed ferns were the undergrowth, difficult to distinguish from spore ferns
High dry ground Plants
Sphenopsids spore-bearing plants, characterized by a jointed
hollow stem
Cordaites seed plants up to 30 m high, gymnosperms (naked
seeds), related to conifers (cone-bearing)
Freshwater and Terrestrial Animals
Freshwater ray-finned fish and sharks flourished
Clams became important in freshwater and brackish environments
Insects, assumed an important ecological role
First insect was early Devonian and wingless
By Late carboniferous many kinds of insects had wings