OHIO

PENNSYLVANIAN

STEM: TETRAPODA GOODRICH, 1930

SUPERCLASS: AMNIOTA HAECKEL, 1866

CLASS: REPTILIA LAURENTI, 1768

SUBCLASS: SYNAPSIDA OSBORN, 1903

ORDER: PELYCOSAURIA COPE, 1878

SUBORDER: EUPELYCOSAURIA KEMP, 1982

INFRAORDER: OPHIACHODONTIA NOVA

Family: OPHIACODONTIDAE Nopsca, 1923

Archaeothyris sp

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