What is the Carboniferous Period?

The Carboniferous Period, the fifth interval of the Paleozoic Era , spanned from approximately 358.9 million to 298.9 million years ago. It is divided into two subperiods: the Mississippian (358.9 to 323.2 million years ago) and the Pennsylvanian (323.2 to 298.9 million years ago). The Carboniferous Period is named for its coal-bearing strata. During the Pennsylvanian subperiod, more coal formed than at any other time in geologic history. During this time, shallow marine and continental environments predominated, with shallow-water limestones in the Northern Hemisphere and continental glaciations in the Southern Hemisphere. Plant and animal life diversified, with significant effects on sedimentary materials. The first reptiles appeared, and amphibians were joined by a variety of insects.

When did the Carboniferous Period occur?

The Carboniferous Period, the fifth interval of the Paleozoic Era, occurred approximately 358.9 million years ago to 298.9 million years ago. Its 60-million-year duration makes it the longest period of the Paleozoic Era and the second longest of the Phanerozoic Eon. The Carboniferous Period is divided into two subperiods: the Mississippian (358.9 to 323.2 million years ago) and the Pennsylvanian (323.2 to 298.9 million years ago). The Carboniferous Period was characterized by variable depositional settings, including shallow marine and continental environments. During this time, plants and animals were diverse and greatly affected the accumulation of sedimentary materials. More coal was formed during the Pennsylvanian subperiod than at any other time in the geologic record. Moderately warm, humid climates combined with high concentrations of carbon dioxide were associated with extensive vegetation.

Why is the Carboniferous Period important in Earth's history?

The Carboniferous Period, lasting from approximately 358.9 million to 298.9 million years ago, is a significant interval of the Paleozoic Era. It is divided into the Mississippian and Pennsylvanian subperiods. During the Carboniferous Period, significant developments occurred: * Coal Formation More coal was formed during the Pennsylvanian subperiod than at any other time in geologic history. The name Carboniferous refers to the coal-bearing strata that characterize the period. * Plant Evolution Terrestrial environments were dominated by vascular land plants, and plant communities became more complex. * Animal Evolution This period saw the peak of amphibian development, the diversification of terrestrial insects, and the emergence of the first reptiles. * Continental Positions The positions of landmasses and prevailing wind patterns influenced regional climates, with tropical conditions in equatorial regions and colder conditions in the higher latitudes of Gondwana, leading to continental glaciations. * Marine Life Diverse marine invertebrates, such as crinoids, dominated benthic marine communities.

What kind of plants and animals lived during the Carboniferous Period?

During the Carboniferous Period, which spanned from approximately 358.9 to 298.9 million years ago, terrestrial environments were dominated by vascular land plants, including lycopods , sphenopsids , cordaites , seed ferns , and true ferns. The period was also marked by the peak of amphibian development and the emergence of reptiles. Insects diversified, with some ancestral dragonflies reaching wingspans of about 70 cm. Marine environments were characterized by diverse invertebrates, with crinoids dominating sea-bottom communities.

How did coal form during the Carboniferous Period?

During the Carboniferous Period (358.9 to 298.9 million years ago), extensive coal deposits formed from plant matter in warm, humid swamp regions. Plant material accumulated in wet, low-lying areas and transformed into peat through microbial activity. This peat was subsequently converted into coal. The vast coal deposits from this period suggest a concurrence of favorable biological and physical processes. The most significant plant groups were lycopods, sphenopsids, cordaites, seed ferns, and true ferns. More coal formed during the Pennsylvanian subperiod than at any other time in the geologic record.

How do scientists study the geochronology of the Carboniferous Period?

Geochronology, the dating of events in Earth's history, relies on relative and absolute chronology. Relative dating puts events in sequence, while radiometric methods provide absolute ages in years. To study the Carboniferous Period , which lasted from approximately 358.9 to 298.9 million years ago, scientists use: Isotopic dating By measuring the amounts of radioactive elements and their decay products in rocks, the time elapsed since the rock formed can be determined. Fossil dating Fossils can be used to correlate rock layers and determine relative ages. Index fossils, which are distinctive, widespread, and short-lived, are particularly useful for this purpose. Lithostratigraphy Physical characteristics of rock layers, such as mineral composition and key beds like volcanic ash, help correlate formations over distances.

Carboniferous Period

Images

A detailed geologic time scale chart displaying Earth's history from the Hadean Eon over 4.5 billion years ago to the present, organized by eons, eras, periods, epochs, and ages with color-coded columns and corresponding dates in millions of years.

Distribution of landmasses, mountainous regions, shallow seas, and deep ocean basins during the Late Carboniferous. Included in the paleogeographic reconstruction are cold and warm ocean currents. The present-day coastlines and tectonic boundaries of the configured continents are shown in the inset.

Paleogeographic map depicting the arrangement of continents during the Late Carboniferous and Early Permian periods, with a large shaded area showing the extent of the Permo-Carboniferous ice sheet around the ancient South Pole. Arrows indicate the direction of ice sheet movement, and dashed lines outline the ice sheet boundary. The map illustrates continental drift and plate tectonics concepts.

Fossilized remains of Cryptoblastus, an extinct genus of blastoids collected from the Burlington Limestone, Iowa.

Dielasma, a genus of extinct brachiopods (lamp shells) occurring as fossils in Carboniferous and Permian rocks.

A chart detailing the Carboniferous period within the Paleozoic era, showing its division into Mississippian and Pennsylvanian subperiods, with corresponding epochs, ages, and their ranges in millions of years ago.

Illustration of the extinct Edaphosaurus, a pelycosaur, showing a reptile-like animal with a large, sail-like fin on its back, squat limbs, and a long tail. A scale bar indicates size.

A timeline chart shows major events in plant evolution alongside the geologic time scale, with illustrations of algae, mosses, ferns, ginkgoes, conifers, cycads, and flowering plants marking their first appearances from the Ordovician to the Cenozoic era. Key milestones such as the emergence of early vascular plants and seed plants are labeled with approximate millions of years ago.

At a Glance

Carboniferous Period summary

Carboniferous Period

geochronology

Written by

Walter L. Manger

Fact-checked by

Britannica Editors

Last updated

Oct. 1, 2026 •History

Top Questions

What is the Carboniferous Period?
The Carboniferous Period, the fifth interval of the Paleozoic Era, spanned from approximately 358.9 million to 298.9 million years ago. It is divided into two subperiods: the Mississippian (358.9 to 323.2 million years ago) and the Pennsylvanian (323.2 to 298.9 million years ago).

The Carboniferous Period is named for its coal-bearing strata. During the Pennsylvanian subperiod, more coal formed than at any other time in geologic history.

During this time, shallow marine and continental environments predominated, with shallow-water limestones in the Northern Hemisphere and continental glaciations in the Southern Hemisphere. Plant and animal life diversified, with significant effects on sedimentary materials. The first reptiles appeared, and amphibians were joined by a variety of insects.
2 Britannica Sources
1. Carboniferous Period
2. A Journey Through Time Since the Precambrian: Carboniferous Period: 358.9 million to about 298.9 million years ago
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
When did the Carboniferous Period occur?
The Carboniferous Period, the fifth interval of the Paleozoic Era, occurred approximately 358.9 million years ago to 298.9 million years ago. Its 60-million-year duration makes it the longest period of the Paleozoic Era and the second longest of the Phanerozoic Eon. The Carboniferous Period is divided into two subperiods: the Mississippian (358.9 to 323.2 million years ago) and the Pennsylvanian (323.2 to 298.9 million years ago).

The Carboniferous Period was characterized by variable depositional settings, including shallow marine and continental environments. During this time, plants and animals were diverse and greatly affected the accumulation of sedimentary materials. More coal was formed during the Pennsylvanian subperiod than at any other time in the geologic record. Moderately warm, humid climates combined with high concentrations of carbon dioxide were associated with extensive vegetation.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Why is the Carboniferous Period important in Earth's history?
The Carboniferous Period, lasting from approximately 358.9 million to 298.9 million years ago, is a significant interval of the Paleozoic Era. It is divided into the Mississippian and Pennsylvanian subperiods.

During the Carboniferous Period, significant developments occurred:
* Coal Formation More coal was formed during the Pennsylvanian subperiod than at any other time in geologic history. The name Carboniferous refers to the coal-bearing strata that characterize the period.
* Plant Evolution Terrestrial environments were dominated by vascular land plants, and plant communities became more complex.
* Animal Evolution This period saw the peak of amphibian development, the diversification of terrestrial insects, and the emergence of the first reptiles.
* Continental Positions The positions of landmasses and prevailing wind patterns influenced regional climates, with tropical conditions in equatorial regions and colder conditions in the higher latitudes of Gondwana, leading to continental glaciations.
* Marine Life Diverse marine invertebrates, such as crinoids, dominated benthic marine communities.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What kind of plants and animals lived during the Carboniferous Period?
During the Carboniferous Period, which spanned from approximately 358.9 to 298.9 million years ago, terrestrial environments were dominated by vascular land plants, including lycopods, sphenopsids, cordaites, seed ferns, and true ferns. The period was also marked by the peak of amphibian development and the emergence of reptiles.

Insects diversified, with some ancestral dragonflies reaching wingspans of about 70 cm. Marine environments were characterized by diverse invertebrates, with crinoids dominating sea-bottom communities.
2 Britannica Sources
1. Carboniferous Period: Amphibians and early reptiles
2. A Journey Through Time Since the Precambrian: Carboniferous Period: 358.9 million to about 298.9 million years ago
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How did coal form during the Carboniferous Period?
During the Carboniferous Period (358.9 to 298.9 million years ago), extensive coal deposits formed from plant matter in warm, humid swamp regions. Plant material accumulated in wet, low-lying areas and transformed into peat through microbial activity. This peat was subsequently converted into coal. The vast coal deposits from this period suggest a concurrence of favorable biological and physical processes. The most significant plant groups were lycopods, sphenopsids, cordaites, seed ferns, and true ferns. More coal formed during the Pennsylvanian subperiod than at any other time in the geologic record.
2 Britannica Sources
1. Carboniferous Period
2. coal: Plant matter
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How do scientists study the geochronology of the Carboniferous Period?
Geochronology, the dating of events in Earth's history, relies on relative and absolute chronology. Relative dating puts events in sequence, while radiometric methods provide absolute ages in years.

To study the Carboniferous Period, which lasted from approximately 358.9 to 298.9 million years ago, scientists use:
- Isotopic dating By measuring the amounts of radioactive elements and their decay products in rocks, the time elapsed since the rock formed can be determined.
- Fossil dating Fossils can be used to correlate rock layers and determine relative ages. Index fossils, which are distinctive, widespread, and short-lived, are particularly useful for this purpose.
- Lithostratigraphy Physical characteristics of rock layers, such as mineral composition and key beds like volcanic ash, help correlate formations over distances.
5 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Carboniferous Period, fifth interval of the Paleozoic Era, succeeding the Devonian Period and preceding the Permian Period. In terms of absolute time, the Carboniferous Period began approximately 358.9 million years ago and ended 298.9 million years ago. Its duration of approximately 60 million years makes it the longest period of the Paleozoic Era and the second longest period of the Phanerozoic Eon. The rocks that were formed or deposited during the period constitute the Carboniferous System. The name Carboniferous refers to coal-bearing strata that characterize the upper portion of the series throughout the world.

The Carboniferous Period is formally divided into two major subdivisions—the Mississippian (358.9 to 323.2 million years ago) and the Pennsylvanian (323.2 to 298.9 million years ago) subperiods—their rocks recognized chronostratigraphically as subsystems by international agreement. In Europe, the Carboniferous Period is subdivided into the Dinantian and succeeding Silesian subsystems, but the boundary between those divisions is below the internationally accepted Mississippian-Pennsylvanian boundary.

The Carboniferous environment

Paleogeography

The Early Carboniferous (Mississippian) world is characterized by Laurussia, a series of small cratonic blocks that occupied the Northern Hemisphere, and Gondwana, an enormous landmass made up of present-day South America, Africa, Antarctica, Australia, and the Indian subcontinent in the Southern Hemisphere. Lithospheric plate movement brought the continents close together on one side of the globe. The orogenies (mountain-building events) taking place during the Devonian Period had formed the “Old Red Sandstone” continent. The principal landmass of Laurussia was made up of present-day North America, western Europe through the Urals, and Balto-Scandinavia. Much of Laurussia lay near the paleoequator, whereas the cratons of Siberia, Kazakhstania, and most of China existed as separate continents occupying positions at high latitudes. During this time, the Tethys Sea separated the southern margin of the Old Red Sandstone continent completely from Gondwana.

By Late Carboniferous (Pennsylvanian) times, plate movements had brought most of Laurussia into contact with Gondwana and closed the Tethys. Laurussia and Gondwana became fused by the Appalachian-Hercynian orogeny (mountain-building event), which continued into the Permian Period. The position of the landmass that would become the eastern United States and northern Europe remained equatorial, while the China and Siberia cratons continued to reside at high latitudes in the Northern Hemisphere.

The distribution of land and sea followed fairly predictable limits. The continental interiors were terrestrial, and no major marine embayments apparently existed. Upland areas of the continental interiors underwent substantial erosion during the Carboniferous. Shallow seas occupied the continental shelf margins surrounding the continents. Fringe areas of Carboniferous continents may very well have become the continental interiors of the present day. Deeper troughs (geosynclines) lay seaward of the continental masses, and their sedimentary record is now characterized by mountains.

Paleoclimate

During the Carboniferous Period, the climate of various landmasses was controlled by their latitudinal position. Since prevailing wind patterns were similar to those on Earth today, tropical conditions characterized the equatorial regions; the midlatitudes were dry, and higher latitudes were both cooler and moist. Although both western Europe and Balto-Scandinavia resided in latitudes low enough to produce evaporite (minerals in sedimentary rock deposits of soluble salts resulting from the evaporation of water) deposits in shallow continental settings, only North America occupied an equatorial setting during the Mississippian. Wetter areas on other continental blocks in higher latitudes of the Northern Hemisphere began to form coal swamps during this time.

In contrast, the bulk of Gondwana was below 30° South latitude and experienced colder conditions that allowed the formation of continental glaciers. These glaciations were similar to those occurring in the Northern Hemisphere during the Pleistocene Epoch. Coeval (parallel) continental glaciations did not occur in the high latitudes of the Northern Hemisphere, probably because the landmasses were too small to sustain large ice fields.

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Paleogeography continued to control climates into Pennsylvanian times. As sea-level cyclicity became more pronounced, the equatorial settings changed from carbonate shelves to coal basins. Continental glaciation expanded in Gondwana, allowing glaciers to extend into lower latitudes that otherwise might have formed coal swamps. As mountains developed toward the close of the Pennsylvanian, rain-shadow effects became more influential, inhibiting the process of coal deposition in the basins of western Europe. Flora of the Carboniferous followed the same climatic gradients as glacial deposits. Fossil plants found in areas located in high latitudes during the Carboniferous exhibit seasonal growth rings, while those of the presumed equatorial coal swamps lack such rings, as do modern tropical trees.

Carboniferous Period

The Carboniferous environment

Paleogeography

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Paleoclimate