Microsauria was named by Dawson (1863). It is not extant. It was considered paraphyletic by Laurin et al. (2000).

It was reranked as the suborder Microsauria by Cope (1875), Hay (1902), Moodie (1909); it was reranked as the subclass Microsauria by Jaekel (1911); it was synonymized subjectively with Lepospondyli by Swinton (1934); it was misspelled as Microsauri by Gadow (1898), Moodie (1916), Perrier (1928), Roxo (1937), Kuhn (1946), Huene (1954), Olson and Barghusen (1962), Olson (1970), Haubold (1971), Daly (1973), Haubold (1974), Carroll and Gaskill (1978), Thayer (1985), Carroll (1988), Gauthier et al. (1989), Carroll (1991), Carroll et al. (1998); it was reranked as the unranked clade Microsauria by Gardiner (1982), Reisz and Modesto (1996), Laurin et al. (2000).

It was assigned to Reptilia by Dawson (1863); to Lepospondyli by Gadow (1898); to Stegocephali by Cope (1875), Hay (1902); to Stegocephala by Moodie (1909); to Miosauria by Jaekel (1911); to Prosauria by Perrier (1928); to Prosauria by Roxo (1937); to Stegocephalia by Kuhn (1946); to Reptiliomorphoidea by Huene (1954); to Lepospondylia by Moodie (1916), Haubold (1974); to Amniota by Gardiner (1982); to Lepospondyli by Olson (1970), Haubold (1971), Daly (1973), Thayer (1985), Carroll (1988); to Tetrapoda by Gauthier et al. (1989); to Amphibia by Olson and Barghusen (1962), Carroll and Gaskill (1978), Carroll (1991); and to Lepospondyli by Reisz and Modesto (1996), Carroll et al. (1998), Laurin et al. (2000).