NEW MEXICO

SANTA FE AND SAN MIGUEL COUNTIES

PECOS RIVER VALLEY LOCAITY

SANGGRE DE CRISTO FORMATION

EARLY PERMIAN

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

Ophiacodon sp

INFRAORDER: DIMETRODONTOMORPHA emend NOPCSA, 1925

Family: SPHENACODONTIDAE Marsh, 1878

Subfamily: SPHENACODONTINAE Marsh, 1878 (sensu Nopcsa, 1925)

Tribe: SPHENACODONTINI Marsh, 1878

Sphenacodon sp