Batrachosauria

a subclass of extinct amphibians. They existed in the northern hemisphere in the Carboniferous and Permian periods. The most highly developed Batrachosauria, the Seymouriamorphs, are similar to reptiles in the construction of their skull and a series of other features. This fact has substantial significance in explaining the evolution of vertebrates. Remains of the Batrachosauria—Lanthanosuchus and Kotlassia—have been found in the territory of the USSR.