Pennsylvanian

Permian

299.0 to 251.0 Million years ago

 Triassic


Plate Tectonic Reconstructions

All of the continents remained fused together in the supercontinent Pangea during this Period. The Permian is the last Period in the Paleozoic Era, ending with the greatest mass extinction known in Earth's history. More than 95% of all species disappeared from the fossil record, with many families, orders, and even classes becoming extinct. The extinctions were spread equally across terrestrial and marine environments.

The Permian was a time of specialization for marine fauna. On land it began with a carboniferous type of flora, changing to a more modern plant types which could colonize dry land as sea levels fell and swamps receded. Insects, amphibians, reptiles, and therapsids (the precursors of mammals flourished during the Permian.

Amphibians are well represented in the Permian fossil record. Permian amphibians were generally large, unlike the salamander sized specimen of Branchiosaurus in this case.

Brachiopods were an important part of the marine fauna for the last time during the Permian, bordering on extinction ever since. represents brachiopods in this display.

Cnidarians (corals): The horn (rugose) corals, such as these examples of solitary coral, and the tabulate corals disappeared forever at the end of the Permian.

Reptiles have an abundant fossil record in this period. Unlike amphibians, reptiles were able to move away from bodies of water due to their desiccation resistant eggs, as represented by this cast of Permianreptile egg.

Trilobites: The Permian saw the last of the trilobites: none survived the great extinction event. Two species are shown: Delaria sp. and Ditomopygie sp.

Conifers readily colonize dry land and increased their abundance during this time. They are characterized by their reproduction via cones. Two specimens of fossil branches and foliage are displayed: Lebachia piniformis and conifer sp.

Plants: Seed ferns are represented by a slab with leaves from Glossopteris sp. and Gangmopteris sp.

The engravings are from Dana, James D. (1870) Manual of Geology, Le Conte, Joseph (1898) A Compend of Geology, Shimer, Harvey Woodburn (1914) An Introduction to the Study of Fossils, or Louis Pirson and Charles Schuchert, A Text-Book of Geology. (1920).


Last modified 22 March 2005| ©1998, HSU NHM