Carboniferous

The Carboniferous is a geological period of the Paleozoic Era that lasted from about 358.9 to 298.9 million years ago. The name, meaning "coal-bearing," reflects the widespread coal beds formed during this time in what are now Europe, North America, and other regions. In modern usage, the period is subdivided into two epochs: the Mississippian (early Carboniferous) and the Pennsylvanian (late Carboniferous).

Climate and environments varied during the Carboniferous. Early Carboniferous climates were generally warm and humid, with extensive swamp forests that produced large quantities of plant material subsequently converted into coal. Vegetation included lycopsids, tree ferns, other ferns, and various seed plants. Some lines of evidence suggest atmospheric oxygen levels may have been higher than today, a factor often linked with the gigantism observed in some arthropods, though this remains a topic of debate. In the later part of the period, global cooling and glaciation on southern Gondwana contributed to sea-level fluctuations and shifts in depositional environments, influencing the distribution of coal swamps and marine habitats.

Biologically, the Carboniferous saw important evolutionary developments. Terrestrial ecosystems supported diversification of amphibians and the early rise of amniotes, the lineage leading to reptiles, birds, and mammals. Plants continued to diversify, with the spread of seed plants and the expansion of coniferous and other gymnosperm groups. In the oceans, groups such as brachiopods, crinoids, and various fishes remained common.

The Carboniferous is notable for its extensive coal formation and for shaping Paleozoic landscapes, climate, and life. It ends with the transition to the Permian, marked by further ecological shifts and tectonic changes associated with the assembly of the supercontinent Pangaea.