COLORADO

LARIMER COUNTY

GREENHORN FORMATION (OLD MIDDLE BENTON FORMATION)

LATE CENOMANIAN STAGE

UPPERMIDDLE GALLIC SUBEPOCH

LOWERMOST GULF EPOCH

MIDDLE CRETACEOUS-EARLY TURONIAN STAGE

LOWER SENONIAN SUBEPOCH

LOWER TO MIDDLE 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: PLESIOSAUROMORPHA NOVA

EUPLESIOSAURIA O’KEEFE, 2001

Superfamily: ELASMOSAUROIDEA nova

Family: ELASMOSAURIDAE Cope, 1869

Gen. sp. indet.