WYOMING

NATRONA COUNTY

RATTLESNAKE HILLS

NEAR CONNANAP CREEK

BELLE FOURCHE SHALE

LOWERMOST CENOMANIAN STAGE

LOWER UPPER MIDDLE GALLIC SUBEPOCH

LOWERMOST GULF EPOCH

MIDDLE CRETACEOUS

STEM: TETRAPODA GOODRICH, 1930

SUPERCLASS: AMNIOTA HAECKEL, 1866

CLASS: REPTILIA LAURENTI, 1768

SUBCLASS: DIAPSIDA OSBORN, 1904

INFRACLASS: EURYAPSIDA COLBERT, 1945

SUPERORDER: SAUROPTERYGIA OWEN, 1860

GRANDORDER: EOSAUROPTERYGIA emend RIEPPEL, 1994

ORDER: PLESIOSAURIA OWEN, 1840 NON BLAINVILLE, 1835

SUBORDER: PLESIOSAURIA OWEN, 1840 NON BLAINVILLE, 1835

INFRAORDER: PLIOSAUROMORPHA NOVA

Superfamily: PLIOSAUROIDEA Seeley, 1874

Family: BRACHAUCHNEIIDAE Williston, 1925

*Plesiopleurodon wellesi

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