4.5 Carboniferous period
10 min read•august 20, 2024
The period, spanning 358.9 to 298.9 million years ago, was a time of extensive and life diversification on land. This era saw the rise of vast coal forests, seed plants, and early amniotes, setting the stage for future evolution.
Divided into the and subperiods, the Carboniferous witnessed major climate shifts and continental reconfigurations. These changes led to the formation of the and the assembly of , shaping Earth's geography and biodiversity.
Carboniferous period overview
- The Carboniferous period, spanning from 358.9 to 298.9 million years ago, was a significant time in Earth's history characterized by extensive coal formation, diversification of life on land, and major climate changes
- This period witnessed the formation of vast coal forests, the evolution of seed plants, and the appearance of early amniotes and reptiles
Division into Mississippian and Pennsylvanian subperiods
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A forest of the Carboniferous period (var.1). by ABelov2014 on DeviantArt View original
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A forest of the Carboniferous period (var.1). by ABelov2014 on DeviantArt View original
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Top images from around the web for Division into Mississippian and Pennsylvanian subperiods
A forest of the Carboniferous period (var.1). by ABelov2014 on DeviantArt View original
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A forest of the Carboniferous period (var.1). by ABelov2014 on DeviantArt View original
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- The Carboniferous 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 Mississippian is characterized by the development of extensive shallow seas, the diversification of marine life, and the emergence of early tetrapods
- The Pennsylvanian is marked by the formation of vast coal swamps, the evolution of seed plants, and the appearance of early amniotes and reptiles
Timespan and duration of Carboniferous
- The Carboniferous period lasted for approximately 60 million years, from 358.9 to 298.9 million years ago
- It follows the Devonian period and precedes the Permian period in the Paleozoic era
Paleogeography of Carboniferous
- The Carboniferous period witnessed significant changes in the configuration of continents and the formation of major mountain ranges, setting the stage for the assembly of the supercontinent Pangaea
Configuration of continents
- During the Carboniferous, the continents were in the process of assembling into the supercontinent Pangaea
- , formed by the collision of Laurentia (North America) and Baltica (Europe), was located in the northern hemisphere
- , a large landmass consisting of present-day South America, Africa, Australia, Antarctica, and India, was situated in the southern hemisphere
Appalachian Mountains formation
- The Carboniferous period saw the formation of the Appalachian Mountains, a major mountain range in eastern North America
- The Appalachian Mountains formed as a result of the collision between Laurussia and Gondwana during the assembly of Pangaea
- The mountain-building event, known as the , led to the uplift and deformation of sedimentary rocks, creating the Appalachian fold belt
Pangaea assembly
- The Carboniferous marked a significant step in the assembly of the supercontinent Pangaea
- The collision of Laurussia and Gondwana, along with the accretion of smaller landmasses, led to the formation of a single, large landmass
- The assembly of Pangaea had profound effects on global climate patterns, ocean circulation, and the distribution of life on Earth
Carboniferous climate
- The Carboniferous period experienced significant climate changes, including glaciation in the southern hemisphere and warm, humid conditions in the equatorial regions
Glaciation in southern hemisphere
- During the Carboniferous, extensive glaciation occurred in the southern hemisphere, particularly in Gondwana
- Glacial deposits and evidence of ice sheets have been found in present-day South America, Africa, Australia, and Antarctica
- The glaciation led to significant changes in sea level, with periods of glacial advance resulting in lowered sea levels and glacial retreat causing sea level rise
Equatorial climate conditions
- The equatorial regions during the Carboniferous experienced warm, humid conditions favorable for the growth of lush vegetation
- High atmospheric carbon dioxide levels and the absence of polar ice caps in the northern hemisphere contributed to the greenhouse climate
- The warm, moist climate supported the development of extensive coal forests, dominated by lycopsids, sphenopsids, and pteridosperms
Climate impact on flora and fauna
- The Carboniferous climate had a significant impact on the distribution and evolution of flora and fauna
- The warm, humid conditions in the equatorial regions supported the growth of dense coal forests, providing habitats for a diverse array of plant and animal life
- The glaciation in the southern hemisphere influenced the distribution of marine and terrestrial organisms, with some groups adapted to colder conditions while others were restricted to warmer regions
Carboniferous flora
- The Carboniferous period is known for its extensive coal forests, which were dominated by lycopsids, sphenopsids, and pteridosperms
Extensive coal forests
- Vast coal forests developed during the Carboniferous, particularly in the equatorial regions
- These forests were characterized by a high diversity of plant life, including lycopsids, sphenopsids, pteridosperms, and early seed plants
- The warm, humid climate and high atmospheric carbon dioxide levels supported the growth of these dense, swampy forests
Lycopsids, sphenopsids, and pteridosperms
- Lycopsids, such as and , were dominant plants in the Carboniferous coal forests
- These plants were characterized by their tall, tree-like growth forms, with scaly bark and leaves arranged in spirals
- Sphenopsids, including and , were also common in the coal forests, with jointed stems and whorled leaves
- Pteridosperms, or seed ferns, were a diverse group of plants that bore seeds but retained fern-like foliage
Evolution of seed plants
- The Carboniferous period witnessed the evolution and diversification of seed plants
- Seed plants, such as and early conifers, developed adaptations that allowed them to reproduce using seeds rather than spores
- The evolution of seeds provided plants with a more efficient means of dispersal and the ability to survive in a wider range of environments
- The appearance of seed plants set the stage for the eventual dominance of gymnosperms and angiosperms in the Mesozoic and Cenozoic eras
Carboniferous fauna
- The Carboniferous period saw a significant diversification of animal life, both in the oceans and on land
Diversification of insects
- Insects underwent a major diversification during the Carboniferous, with the appearance of many new groups and the evolution of flight
- Carboniferous insects included early forms of dragonflies (), cockroaches, and mayflies
- The warm, humid climate and abundant plant life provided ideal conditions for insect diversification
Giant arthropods and amphibians
- The Carboniferous period is known for its giant arthropods, such as the massive millipede-like and the large dragonfly-like Meganeura
- These arthropods reached sizes much larger than their modern counterparts, likely due to the in the atmosphere
- Amphibians also thrived during the Carboniferous, with the appearance of large, predatory forms such as and the snake-like Ophiderpeton
Early amniotes and reptiles
- The Carboniferous witnessed the appearance of early amniotes and reptiles, which laid the foundation for the evolution of modern reptiles, birds, and mammals
- Early amniotes, such as and , developed the ability to lay eggs on land, reducing their dependence on water for reproduction
- The first true reptiles, such as , appeared during the late Carboniferous, exhibiting adaptations for a fully terrestrial lifestyle
Carboniferous coal deposits
- The Carboniferous period is named for the extensive coal deposits that formed during this time, which are of great economic significance
Formation process of coal
- Coal deposits formed from the remains of the dense vegetation that grew in the Carboniferous swamps and forests
- As plants died and accumulated in swampy environments, they were buried by sediments and subjected to high pressure and temperature over millions of years
- The process of coalification transformed the plant material into peat, lignite, bituminous coal, and eventually anthracite coal, depending on the degree of alteration
Distribution of coal deposits
- Carboniferous coal deposits are found on all continents, with major reserves in North America, Europe, Asia, and Australia
- The distribution of coal deposits is closely related to the paleogeography of the Carboniferous, with most deposits occurring in regions that were once part of the equatorial coal forests
- Significant coal basins include the Appalachian Basin in the United States, the Donets Basin in Ukraine, and the Bowen Basin in Australia
Economic significance of coal
- Carboniferous coal deposits are of immense economic importance, serving as a major source of energy for industrial and domestic use
- Coal has been a key factor in the development of modern industries, including steel production, electricity generation, and chemical manufacturing
- The exploitation of Carboniferous coal deposits has played a significant role in shaping the global economy and has had far-reaching environmental and social impacts
Carboniferous mass extinction
- The Carboniferous period witnessed significant changes in biodiversity, including the recovery from the Late Devonian extinction and the onset of the Carboniferous-Permian extinction event
Late Devonian extinction recovery
- The Late Devonian extinction, which occurred prior to the Carboniferous, had a significant impact on marine life, particularly reef-building organisms and trilobites
- During the early Carboniferous (Mississippian), marine ecosystems gradually recovered, with the diversification of new groups such as crinoids, bryozoans, and brachiopods
- The recovery of marine life set the stage for the development of extensive reef systems and the colonization of new ecological niches
Carboniferous-Permian extinction event
- The late Carboniferous to early Permian witnessed a gradual decline in biodiversity, known as the Carboniferous-Permian extinction event
- This extinction event primarily affected marine invertebrates, such as trilobites, rugose and tabulate corals, and some groups of brachiopods and bryozoans
- The causes of the Carboniferous-Permian extinction are not fully understood but may include changes in sea level, climate, and ocean chemistry
Causes and consequences of extinctions
- The Carboniferous-Permian extinction event is thought to have been caused by a combination of factors, including glaciation, changes in ocean circulation, and fluctuations in sea level
- The extinction of certain marine groups, such as trilobites and rugose corals, led to the restructuring of marine communities and the rise of new dominant groups
- The ecological changes associated with the Carboniferous-Permian extinction event set the stage for the evolution and diversification of life in the Permian period
Carboniferous reef environments
- The Carboniferous period saw the development of extensive reef systems, which supported a high diversity of marine life
Abundance of reef-building organisms
- Carboniferous reefs were constructed by a variety of organisms, including rugose and tabulate corals, stromatoporoids, and calcareous algae
- These reef-building organisms thrived in the warm, shallow seas that characterized much of the Carboniferous, particularly during the Mississippian subperiod
- The abundance of reef-building organisms led to the formation of large, complex reef structures that provided habitats for a wide range of marine life
Reef types and distribution
- Carboniferous reefs occurred in various forms, including fringing reefs, barrier reefs, and atolls
- Reefs were widely distributed across the shallow seas that covered much of the continents during the Carboniferous
- Major reef systems have been identified in North America (e.g., the Mississippian Madison Limestone), Europe (e.g., the Carboniferous Limestone of the British Isles), and Asia (e.g., the Carboniferous reefs of China)
Reef ecology and biodiversity
- Carboniferous reefs supported a high diversity of marine life, including invertebrates, fish, and early sharks
- Reef environments provided a variety of ecological niches, allowing for the coexistence of numerous species with different feeding strategies and life habits
- The complex structure of reefs also offered protection from predation and environmental stresses, contributing to the high biodiversity observed in these ecosystems
Carboniferous ocean chemistry
- The Carboniferous period witnessed significant changes in ocean chemistry, which had important implications for marine life and sediment deposition
Anoxic conditions in oceans
- During the Carboniferous, particularly in the Mississippian subperiod, some parts of the oceans experienced anoxic conditions, characterized by low oxygen levels in the water column
- Anoxia was likely caused by a combination of factors, including high organic matter input from the continents, sluggish ocean circulation, and warm global temperatures
- Anoxic conditions had a profound impact on marine life, with only certain groups (e.g., some brachiopods and bivalves) able to tolerate the low-oxygen environments
Black shale deposition
- The anoxic conditions in the Carboniferous oceans led to the deposition of black shales, which are dark-colored, organic-rich sedimentary rocks
- Black shales form in oxygen-depleted environments where the decay of organic matter is slowed down, allowing for the preservation of organic carbon
- Carboniferous black shales are important source rocks for hydrocarbons (oil and gas) and can provide valuable insights into the ocean chemistry and environmental conditions of the time
Geochemical proxies for ocean chemistry
- Geochemical proxies, such as stable isotope ratios and trace element concentrations, can be used to reconstruct the ocean chemistry of the Carboniferous period
- Carbon and oxygen isotope ratios from marine carbonates (e.g., brachiopod shells) can provide information on the global and ocean temperature
- Trace element concentrations (e.g., molybdenum, vanadium) in black shales can be used to infer the redox conditions of the oceans and the extent of anoxia
Carboniferous as foundation for Permian
- The Carboniferous period set the stage for the evolution and diversification of life in the Permian, through a combination of evolutionary innovations and environmental changes
Transition to Permian period
- The transition from the Carboniferous to the Permian period was marked by significant changes in climate, paleogeography, and biotic composition
- The amalgamation of Pangaea led to the formation of large, continental landmasses and the development of new terrestrial environments
- The gradual aridification of the climate during the late Carboniferous and early Permian had a profound impact on the distribution and evolution of flora and fauna
Evolutionary innovations in Carboniferous
- The Carboniferous period witnessed several key evolutionary innovations that would have far-reaching consequences for life in the Permian and beyond
- The evolution of seed plants, particularly the appearance of early conifers and cycads, set the stage for the dominance of gymnosperms in the Permian
- The appearance of amniote eggs allowed early tetrapods to become fully terrestrial, paving the way for the diversification of reptiles and synapsids in the Permian
Carboniferous influence on Permian biota
- Many of the major groups that would dominate the Permian, such as reptiles, synapsids, and insects, had their origins in the Carboniferous period
- The ecological and evolutionary changes that occurred during the Carboniferous, such as the diversification of seed plants and the colonization of new terrestrial environments, had a profound influence on the composition and structure of Permian ecosystems
- The extinction events of the late Carboniferous and early Permian also played a role in shaping the biotic composition of the Permian, by removing some groups and creating opportunities for others to diversify
Key Terms to Review (30)
Alleghenian Orogeny: The Alleghenian Orogeny was a significant mountain-building event that occurred during the late Paleozoic era, primarily during the Carboniferous and into the Permian periods. It resulted from the collision of tectonic plates, leading to the uplift of the Appalachian Mountains and influencing the geological landscape of eastern North America. This orogeny played a crucial role in shaping the geological history of the region, including the formation of coal deposits and the evolution of terrestrial ecosystems.
Ammonites: Ammonites are an extinct group of marine mollusks belonging to the class Cephalopoda, characterized by their spiral-shaped shells and complex suture patterns. These fascinating creatures flourished during the Mesozoic Era, particularly from the late Paleozoic through the end of the Cretaceous period, and they are often used as important index fossils for dating rock layers.
Appalachian Mountains: The Appalachian Mountains are a major mountain range in eastern North America, extending from Canada to Alabama. Known for their rich biodiversity and unique geology, these mountains played a crucial role in the Carboniferous period, serving as a significant region for the deposition of coal-forming plant material.
Arthropleura: Arthropleura was a giant millipede-like arthropod that lived during the Carboniferous period, reaching lengths of up to 2.5 meters (about 8 feet). This creature is significant as it exemplifies the evolution of terrestrial arthropods and highlights the diverse ecosystems that existed during this time, characterized by lush vegetation and high oxygen levels which supported larger body sizes.
Biostratigraphy: Biostratigraphy is a branch of stratigraphy that uses the distribution of fossil organisms to date and correlate rock layers. This method is crucial in understanding the history of life on Earth, helping scientists identify and classify different geological time units based on the fossils found within them.
Calamites: Calamites refers to an extinct genus of tree-like plants that thrived during the Carboniferous period, resembling modern horsetails but reaching heights of up to 30 meters. These plants were an important component of ancient swamp ecosystems, contributing to the formation of coal deposits and showcasing the diversity of flora during this time.
Carbon cycle: The carbon cycle is the process through which carbon is exchanged between the Earth's atmosphere, oceans, soil, and living organisms. This cycle plays a crucial role in regulating Earth's climate and supporting life by facilitating the movement of carbon through various forms such as carbon dioxide, organic matter, and fossil fuels. Understanding this cycle is essential for grasping the dynamics of ecosystems and the impact of human activities on climate change.
Carboniferous: The Carboniferous is a geological period that lasted from about 359 to 299 million years ago, known for its significant development of terrestrial ecosystems and the extensive formation of coal deposits. This period is marked by the emergence of lush forests dominated by ferns, horsetails, and the first seed-bearing plants, making it a critical time for both plant evolution and carbon storage.
Coal formation: Coal formation is the geological process that transforms plant material into coal over millions of years through the stages of accumulation, compaction, and chemical alteration. This process primarily occurs in swampy environments where dead plant matter accumulates and is buried under sediment, eventually leading to the creation of different types of coal based on temperature and pressure conditions.
Cordaites: Cordaites are an extinct group of seed plants that thrived during the Carboniferous period, characterized by their tall tree-like forms and distinctive leaf structures. These plants played a vital role in the ecosystem of the time, contributing to the formation of coal deposits and serving as important components of ancient swampy forests. Their adaptations to wetland environments highlight their significance in understanding the evolution of terrestrial flora during this period.
Eryops: Eryops is a genus of extinct amphibians that lived during the late Carboniferous to early Permian periods, known for its robust body and distinct characteristics that showcase the transition from aquatic to terrestrial life. As a large, predatory amphibian, it represents a significant evolutionary step as vertebrates adapted to land environments, highlighting important changes in anatomy and behavior during this time.
Forest ecosystems: Forest ecosystems are complex communities of plants, animals, and microorganisms that interact with each other and their physical environment within forested areas. These ecosystems play a crucial role in carbon storage, biodiversity, and influencing local climates, particularly during the Carboniferous period when lush forests contributed significantly to global carbon levels.
Glossopteris: Glossopteris is an extinct genus of seed ferns that thrived during the late Paleozoic Era, particularly notable during the Carboniferous period. This plant was characterized by its distinctive tongue-shaped leaves and played a significant role in understanding ancient climates and biogeography, as its fossils have been found on multiple continents, indicating a once-connected landmass.
Gondwana: Gondwana was a supercontinent that existed from the Late Precambrian to the Jurassic period, comprising landmasses that are now part of Africa, South America, Antarctica, Australia, and the Indian subcontinent. This massive landmass played a crucial role in shaping the geological and biological history of Earth, particularly influencing the evolution and distribution of species during various geological periods.
High oxygen levels: High oxygen levels refer to periods in Earth's history when the concentration of oxygen in the atmosphere and oceans was significantly elevated, particularly during the Carboniferous period. This increase in atmospheric oxygen had a profound impact on the environment, leading to the flourishing of diverse plant and animal life, especially large arthropods and lush forests. The high oxygen levels also contributed to the development of coal deposits, which are a hallmark of this geological time frame.
Hylonomus: Hylonomus is an extinct genus of early reptile that lived during the Carboniferous period, around 300 million years ago. It is considered one of the earliest known amniotes, showcasing significant adaptations for terrestrial life, such as a fully formed egg that could be laid on land, setting the stage for future reptiles and mammals.
Laurussia: Laurussia refers to a supercontinent that formed during the late Paleozoic Era, primarily consisting of present-day North America and Europe. It played a crucial role in shaping the Earth's geological and biological landscape during significant periods such as the Devonian and Carboniferous, contributing to changes in climate, sea levels, and the distribution of flora and fauna.
Lepidodendron: Lepidodendron is a genus of extinct tree-like plants that thrived during the Carboniferous period, characterized by their scale-like leaves and large trunks that could reach impressive heights. These plants played a crucial role in the formation of coal deposits during this time, as they grew in dense forests that dominated the landscape, contributing significantly to the carbon cycle and shaping the Earth's atmosphere.
Lycophytes: Lycophytes are a group of seedless vascular plants that include clubmosses, spikemosses, and quillworts. They are characterized by their small, scale-like leaves called microphylls and their ability to reproduce via spores instead of seeds. These ancient plants played a significant role in Earth's history, particularly during the Carboniferous period, when they thrived in lush forests and contributed to the formation of coal deposits.
Mass extinction: Mass extinction refers to a significant and rapid decline in the biodiversity of life on Earth, characterized by the loss of a large number of species over a relatively short geological time frame. This phenomenon often reshapes ecosystems and paves the way for new species to emerge, marking important transitions in the history of life.
Meganeura: Meganeura is an extinct genus of giant dragonflies that lived during the Carboniferous period, approximately 300 million years ago. These prehistoric insects are notable for their impressive wingspan, reaching lengths of up to 75 centimeters (about 30 inches), making them some of the largest flying insects to have ever existed. Their size is attributed to the high oxygen levels present in the atmosphere during the Carboniferous, which supported larger body sizes in terrestrial and aerial organisms.
Mississippian: The Mississippian is a geological period that occurred from approximately 359 to 323 million years ago, within the larger Carboniferous period. This era is marked by significant developments in terrestrial ecosystems and the emergence of extensive forests dominated by seedless vascular plants, which played a crucial role in the evolution of early terrestrial life.
Paleoecology: Paleoecology is the study of ancient ecosystems and the relationships between organisms and their environments over geological time. It helps scientists understand how past climates, biotic interactions, and geological processes shaped the distribution and evolution of life on Earth, linking it to various periods and events in Earth’s history.
Paleothyris: Paleothyris is an extinct genus of reptile that lived during the Carboniferous period, specifically characterized by its unique cranial features and adaptations. It is significant for understanding the evolution of early amniotes and the ecological dynamics of terrestrial environments during this time. This genus provides insights into the transition from amphibian-like ancestors to more advanced reptiles, showcasing the diversity and complexity of life in the Carboniferous period.
Pangaea: Pangaea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras, bringing together almost all of Earth's landmasses into a single, large landmass. Its formation significantly impacted global climate, ocean currents, and the evolution of life by altering habitats and encouraging species diversification. The breakup of Pangaea led to the current configuration of continents and played a vital role in shaping Earth's geological and biological history.
Pennsylvanian: The Pennsylvanian refers to a geological subperiod within the Carboniferous period, lasting from approximately 323 to 299 million years ago. This time frame is marked by significant developments in terrestrial ecosystems, including the formation of extensive coal deposits and the proliferation of diverse plant and animal life, particularly amphibians and early reptiles.
Petrolacosaurus: Petrolacosaurus is an extinct genus of reptiles that lived during the late Carboniferous period, known for its early evolutionary traits that hint at the transition from reptiles to mammals. This genus is significant as it provides insight into the morphological changes and adaptations of amniotes during this time, contributing to our understanding of vertebrate evolution.
Sigillaria: Sigillaria refers to a genus of extinct tree-like plants that thrived during the Carboniferous period, characterized by their tall, columnar trunks and distinctive leaf scars. These plants were a significant part of the ancient swampy ecosystems, contributing to the formation of coal deposits that we rely on today. Sigillaria is often associated with the lush, dense forests of the Carboniferous, which played a crucial role in shaping Earth's carbon cycle.
Sphenophyllum: Sphenophyllum is an extinct genus of plants that belonged to the group of vascular plants known as the Sphenopsida, which thrived during the Carboniferous period. Characterized by their distinctive whorled leaves and jointed stems, these plants played a significant role in the ancient ecosystems, contributing to the lush, swampy environments typical of that time. Their structure and reproductive features provide insights into the evolution of early terrestrial flora.
Tropical climate: A tropical climate is characterized by consistently high temperatures throughout the year, typically with an average monthly temperature above 18°C (64°F). This climate often includes distinct wet and dry seasons and is found near the equator, where the sun's rays are most direct, fostering lush vegetation and diverse ecosystems.