Microsauria ("small lizards") is an extinct, possibly polyphyletic[1] clade of tetrapods from the late Carboniferous and early Permian periods.

The group included lizard-like animals that were relatively well-adapted to living on dry land, burrowing forms, and others that, like the modern axolotl, retained their gills into adult life, and so presumably never left the water.

[7] Microsaur remains have been found from Europe and North America in Late Carboniferous and Early Permian localities.

Possible microsaur remains have also been found from strata in the town of Vyazniki in the Vladimir Oblast of Russia.

[13] Cladogram modified from Anderson (2001), with microsaur taxa marked with yellow highlight:[4] Utaherpeton Hyloplesion Odonterpeton Saxonerpeton Hapsidopareion Llistrofus Asaphestera Tuditanus Micraroter Pelodosotis Pantylus Stegotretus Sparodus Cardiocephalus Euryodus Rhynchonkos Eocaecilia (Lissamphibia) Batropetes Carrolla Quasicaecilia Microbrachis Adelospondyli Scincosaurus Sauropleura Urocordylus Ctenerpeton Ptyonius Batrachiderpeton Keraterpeton Diceratosaurus Diploceraspis Diplocaulus Lysorophia Aïstopoda Cladogram from Ruta and Coates (2007):[5] Odonterpeton Hyloplesion Microbrachis Brachystelechidae Tuditanidae Hapsidopareiontidae Ostodolepidae Rhynchonkos Gymnarthridae Pantylidae Lysorophia Nectridea Aïstopoda Cladistic analysis by Pardo et al. (2017) places recumbirostran microsaurs and lysorophians as members of Amniota.