Smithsonian National Museum of Natural History Geologic Time The Story of a Changing Earth
Presented by the Department of Paleobiology.
The Pennsylvanian
Contents
Overview
Pennsylvanian Animal Life
Plant Life and the Coal Forests
Pennsylvanian Climate and Tectonics
Evidence
Annularia stellata, an extinct tree-like horsetail
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sample
Carboniferous Tree Fern
Fossil spider
references and links
Foundational Concepts
Dating Methods
Earth Processes
Life Processes
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Glossary Credits Email Us


Plant Life and the Coal Forests
The plants of the Pennsylvanian are among the best known of all geological time periods, thanks to fossils found in the world’s abundant coal seams. Three basic floras inhabited the climatic zones of the time: the northern Angaran temperate flora, the southern Gondwanan temperate flora, and the Euramerican tropical flora. Each of these floristic regions was distinct in terms of its plant composition. Paratropical vegetation may have existed near the tropical zones as well.

The Tropics are the best known of these major floras and were home to gigantic peat-forming forests. These ultimately gave rise to most of the coal beds of the eastern and central United States and western Europe. The dominant plants in these coal beds represented several major groups: lycopsids (giant club mosses such as Lepidodendron, Lepidophloios, and Sigillaria), Marattiales (tree ferns), calamites (giant horsetails such as Asterophyllities and Annularia), pteridosperms (seed ferns such as Neuropteris, Alethopteris, and Mariopteris), and cordaites (conifer-like plants). In the coal-swamp forests of Euramerica, plant organs such as the stems of marattialean ferns, the leaves of seed ferns, the prepollen of cordaites, and the sporangia of herbaceous ferns were being consumed by a plethora of chewing and piercing-and-sucking insects. The Angaran temperate realm is also fairly well known, and in the Late Pennsylvanian it was dominated by cordaite-like seed plants known as ruflorians. Gondwana was also rich in seed plants, especially the deciduous tree Glossopteris.

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Overview | Pennsylvanian Animal Life | Plant Life and the Coal Forests
Pennsylvanian Climate and Tectonics



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