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.