Anthracosauria

Anthracosauria is an extinct group of tetrapods that lived during the Carboniferous and Permian periods. These amphibians were characterized by their relatively robust bodies, long tails, and often large size. They are considered to be among the earliest amniote-like tetrapods, showing a transitional morphology between more primitive amphibians and the first reptiles. Their name, "Anthracosauria," literally means "coal lizard," reflecting the period and environment in which many of their fossils were found.

These creatures were primarily aquatic or semi-aquatic, with many possessing adaptations for life in freshwater environments, such as gills and external fertilization. However, some anthracosaurs may have begun to develop more terrestrial adaptations, such as stronger limbs and a more amniote-like skull, hinting at the evolutionary lineage leading to true reptiles. Their diet likely consisted of fish, invertebrates, and possibly smaller tetrapods.

The fossil record of anthracosaurs is found in deposits across North America, Europe, and Asia. Their ecological roles varied, with some acting as apex predators in their aquatic habitats. While they are not direct ancestors of modern amphibians, their study provides crucial insights into the evolutionary transition from water-dwelling vertebrates to land-dwelling tetrapods and the subsequent diversification of terrestrial life. The group's precise phylogenetic position has been debated, but they are generally placed within the Reptiliomorpha, a clade that includes reptiles and their closest extinct relatives.