Protorothyrididae

Hylonomus (; from Greek , meaning , and , meaning ) is an extinct genus of early (possibly stem group) amniote that lived during the Bashkirian stage of the Late Carboniferous. The genus contains a single species, Hylonomus lyelli.

Paleothyris is an extinct genus of small reptiliomorph which lived in the Moscovian (Carboniferous) age of the Late Carboniferous in Nova Scotia.

left|thumb|Skull of Paleothyris Protorothyrididae is an extinct proposed family of small, lizard-like reptiliomorphs traditionally thought to be early members of "Eureptilia". Their skulls did not have the fenestrae seen in the more derived diapsids. Protorothyridids lived from the late Carboniferous to early Permian periods, in what is now North America.

alt=Artist's reconstruction of Protorothyris|left|thumb|Life restoration Protorothyris is an extinct genus of Early Permian protorothyridid known from Texas and West Virginia of the United States. It was first named by Llewellyn Ivor Price in 1937 and the type species is Protorothyris archeri. P. archeri is known from the holotype MCZ 1532, a three-dimensionally preserved skull and from the referred specimens, which come from four additional individuals, MCZ 2147-2150. All specimens were collected in the Cottonwood Creek site, from the Archer City Formation, Texas, dating to the Asse