GEOL 102 Historical Geology

Spring Semester 2011
The Late Paleozoic Era III: Life in the Coal Swamps

Late Paleozoic marine life:
Marine life of the Mississippian:
Many groups (tabulates, stromatoporoids, trilobites, placoderms) never recover in diversity from Late Devonian mass extinctions.

Others flourish: crinoids and blastoids do amazingly well, as do lacy bryozoans, brachiopods, ammonoids, sharks and actinopterygians.

Crinoid meadows: huge fields of crinoids and associated organisms.

Fusulinids: a type of foraminferan (armored single-celled eukaryote) appear: more important in Pennsylvanian.

Marine life of the Pennsylvanian:
Much as in Mississippian.

Fusulinids highly diverse, become important index fossils.

Marine life of the Permian:
Permian reef community: sponges and bryozoans as primary framework builders.

Brachiopods are extremely abundant, particularly large sediment sitters.

End of Permian: largest extinction in history of the marine realm: see next lecture

Late Paleozoic terrestrial life: Plants
Carboniferous flora:
Convergent evolution of the tree among many sorts of vascular plants. Diverse forests.

Major groups:

As the world began to dry out during the Late Pennsylvanian, scale tree and calamite forests decline as seed plant forests rise. Scale trees and cordaites die out at end of Pennsylvanian.

Permian flora:
Calamites die off in Early Permian.

Coal swamps decline over most of the world (not in China and in high latitudes of Pangaea).

Glossopteris: a "seed-fern" which was the most important member of the Glossopteris Flora of Gondwana. Adapted to upland, drier, cold environments.

Also, first ginkgos (not important until Triassic).

Conifers also diversity in Permian.

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Last modified: 14 January 2011