Carboniferous

Carboniferous
358.9 ± 0.4 – 298.9 ± 0.15 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Map of Earth as it appeared 320 million years ago during the Carboniferous period, Pennsylvanian subperiod[citation needed]
Chronology
−360 — – −355 — – −350 — – −345 — – −340 — – −335 — – −330 — – −325 — – −320 — – −315 — – −310 — – −305 — – −300 — – Paleozoic Devonian Carboniferous Permian Mississippian Pennsylvanian Early Middle Late Early Mid Late Tournaisian Viséan Serpukhovian Bashkirian Moscovian Kasimovian Gzhelian     ← Carboniferous Rainforest Collapse ← Mazon Creek Fossils ← End of Romer's Gap ← Start of Romer's Gap Subdivision of the Carboniferous according to the ICS, as of 2021.[1] Vertical axis scale: millions of years ago
Etymology
Name formality	Formal
Nickname(s)	Age of Amphibians
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Period
Stratigraphic unit	System
First proposed by	William Daniel Conybeare and William Phillips, 1822
Time span formality	Formal
Lower boundary definition	FAD of the Conodont Siphonodella sulcata (discovered to have biostratigraphic issues as of 2006)[2]
Lower boundary GSSP	La Serre, Montagne Noire, France 43°33′20″N 3°21′26″E / 43.5555°N 3.3573°E / 43.5555; 3.3573
Lower GSSP ratified	1990[3]
Upper boundary definition	FAD of the Conodont Streptognathodus isolatus within the morphotype Streptognathodus wabaunsensis chronocline
Upper boundary GSSP	Aidaralash, Ural Mountains, Kazakhstan 50°14′45″N 57°53′29″E / 50.2458°N 57.8914°E / 50.2458; 57.8914
Upper GSSP ratified	1996[4]
Atmospheric and climatic data
Sea level above present day	Falling from 120 m to present-day level throughout the Mississippian, then rising steadily to about 80 m at end of period[5]

The Carboniferous (/ˌkɑːrbəˈnɪfərəs/ KAR-bə-NIF-ər-əs)^[6] is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period 358.9 Ma (million years ago) to the beginning of the Permian Period, 298.9 Ma. It is the fifth and penultimate period of the Paleozoic and the fifth period of the Phanerozoic. In North America, the Carboniferous is often treated as two separate geological periods, the earlier Mississippian and the later Pennsylvanian.^[7]

The name Carboniferous means "coal-bearing", from the Latin carbō ("coal") and ferō ("bear, carry"), and refers to the many coal beds formed globally during that time.^[8] The first of the modern "system" names, it was coined by geologists William Conybeare and William Phillips in 1822,^[9] based on a study of the British rock succession.

Carboniferous is the period during which both terrestrial animal and land plant life was well established.^[10] Stegocephalia (four-limbed vertebrates including true tetrapods), whose forerunners (tetrapodomorphs) had evolved from lobe-finned fish during the preceding Devonian period, became pentadactylous during the Carboniferous.^[11] The period is sometimes called the Age of Amphibians^[12] because of the diversification of early amphibians such as the temnospondyls, which became dominant land vertebrates,^[13] as well as the first appearance of amniotes including synapsids (the clade to which modern mammals belong) and sauropsids (which include modern reptiles and birds) during the late Carboniferous. Land arthropods such as arachnids (e.g. trigonotarbids and Pulmonoscorpius), myriapods (e.g. Arthropleura) and especially insects (particularly flying insects) also underwent a major evolutionary radiation during the late Carboniferous. Vast swaths of forests and swamps covered the land, which eventually became the coal beds characteristic of the Carboniferous stratigraphy evident today.

The later half of the period experienced glaciations, low sea level, and mountain building as the continents collided to form Pangaea. A minor marine and terrestrial extinction event, the Carboniferous rainforest collapse, occurred at the end of the period, caused by climate change.^[14] Atmospheric oxygen levels, originally thought to be consistently higher than today throughout the Carboniferous, have been shown to be more variable, increasing from low levels at the beginning of the Period to highs of 25-30%.^[15]