Microsauria

Microsauria is an extinct informal group of small, lizard-like amphibians that lived during the Carboniferous and Permian periods. These early tetrapods were characterized by their relatively small size, typically no more than a meter in length, and a generally elongated body with a long tail. Microsauria is a paraphyletic group, meaning it includes a common ancestor and some, but not all, of its descendants. They are often considered to be among the most basal or primitive of the lepospondyl amphibians.

The exact evolutionary relationships of microsaurians are still a subject of ongoing research and debate among paleontologists. However, they are generally placed within the larger group Lepospondyli, which is distinct from the temnospondyls and other major amphibian lineages. Microsaurians possessed a variety of adaptations, suggesting they occupied diverse ecological niches. Some species likely lived in aquatic environments, while others were terrestrial or fossorial (burrowing). Their diet likely varied, with evidence suggesting some were insectivores or carnivores.

Fossil remains of microsaurians have been found in various parts of the world, particularly in North America and Europe. Their skeletal features, such as their vertebrae and skull structure, provide key characteristics for their classification and understanding of their biology. The diversity within Microsauria, though now extinct, offers insights into the early diversification of tetrapods and the evolutionary pathways taken by amphibians during the Paleozoic Era. Their extinction marks the end of a significant branch of early vertebrate evolution.