SUPERCLASS: AMNIOTA HAECKEL, 1866

CLASS: REPTILIA LAURENTI, 1768

SUBCLASS: DIAPSIDA OSBORN, 1903

INFRACLASS: NEODIAPSIDA BENTON, 1985

LEGION: LEPIDOSAUROMORPHA BENTON, 1983

SUBLEGION: LEPIDOSAURIA HAECKEL, 1866 (DUMERIL & BIBRON, 1839)

MAGNORDER: SQUAMATA, OPPEL, 1811

SUPERORDER: LACERTILIA OWEN, 1842

GRANDORDER: SCINCOGEKKONOMORPHA SUKHANOV, 1961

MICRORDER: SCINCOMORPHA CAMP, 1923

ORDER: ANGUIMORPHA FURBRINGER, 1900

SUBORDER: DIPLOGLOSSA COPE, 1864

INFRAORDER: THECAGLOSSA COPE, 1890

PARVORDER: MONSTERSAURIA NORELL & GAO, 1977

Superfamily: VARANOIDEA Gray, 1827 (sensu Camp, 1923)

Family: MOSASAURIDAE Gervais, 1853

Infrafamily: NATANIA

Subfamily: MOSASAURINAE Gervais, 1853 (sensu Williston, 1897)

Tribe: MOSASAURINI Gervais, 1853 (sensu Russell, 1967)

Mosasaurus nova

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SOUTH DAKOTA

LYMAN COUNTY

SHARON SPRINGS MEMBER

PIERRE SHALE

UPPER LOWER TO LOWER MIDDLE CAMPANIAN STAGE

SENONIAN SUBEPOCH

UPPER GULF EPOCH

LATE CRETACEOUS

STEM: TETRAPODA GOODRICH, 1930

SUPERCLASS: AMNIOTA HAECKEL, 1866

CLASS: REPTILIA LAURENTI, 1768

SUBCLASS: DIAPSIDA OSBORN, 1903

INFRACLASS: NEODIAPSIDA BENTON, 1985

LEGION: LEPIDOSAUROMORPHA BENTON, 1983

SUBLEGION: LEPIDOSAURIA HAECKEL, 1866 (DUMERIL & BIBRON, 1839)

MAGNORDER: SQUAMATA, OPPEL, 1811

SUPERORDER: LACERTILIA OWEN, 1842

GRANDORDER: SCINCOGEKKONOMORPHA SUKHANOV, 1961

MICRORDER: SCINCOMORPHA CAMP, 1923

ORDER: ANGUIMORPHA FURBRINGER, 1900

SUBORDER: DIPLOGLOSSA COPE, 1864

INFRAORDER: THECAGLOSSA COPE, 1890

PARVORDER: MONSTERSAURIA NORELL & GAO, 1977

Superfamily: VARANOIDEA Gray, 1827 (sensu Camp, 1923)

Family: MOSASAURIDAE Gervais, 1853

Infrafamily: NATANIA

Subfamily: RUSSELLOSAURINAE Bell, 1993

Tribe: PLIOPLATECARPINI Dollo, 1884 (sensu Russell, 1967)

Platecarpus sp

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SOUTH DAKOTA

LYMAN COUNTY

NICHOLAS CREEK

SHARON SPRINGS MEMBER

PIERRE SHALE

UPPER LOWER TO LOWER MIDDLE CAMPANIAN STAGE

SENONIAN SUBEPOCH

UPPER GULF EPOCH

LATE CRETACEOUS

STEM: TETRAPODA GOODRICH, 1930

SUPERCLASS: AMNIOTA HAECKEL, 1866

CLASS: REPTILIA LAURENTI, 1768

SUBCLASS: DIAPSIDA OSBORN, 1903

INFRACLASS: NEODIAPSIDA BENTON, 1985

LEGION: LEPIDOSAUROMORPHA BENTON, 1983

SUBLEGION: LEPIDOSAURIA HAECKEL, 1866 (DUMERIL & BIBRON, 1839)

MAGNORDER: SQUAMATA, OPPEL, 1811

SUPERORDER: LACERTILIA OWEN, 1842

GRANDORDER: SCINCOGEKKONOMORPHA SUKHANOV, 1961

MICRORDER: SCINCOMORPHA CAMP, 1923

ORDER: ANGUIMORPHA FURBRINGER, 1900

SUBORDER: DIPLOGLOSSA COPE, 1864

INFRAORDER: THECAGLOSSA COPE, 1890

PARVORDER: MONSTERSAURIA NORELL & GAO, 1977

Superfamily: VARANOIDEA Gray, 1827 (sensu Camp, 1923)

Family: MOSASAURIDAE Gervais, 1853

Infrafamily: NATANIA

Subfamily: TYLOSAURINAE Williston, 1897

Incertae sedis

Gen. sp indet.

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SOUTH DAKOTA

LYMAN COUNTY

ALONG THE MISSOURI RIVER

AT WATER LEVEL NEAR THE MOUTH OF NICHOLAS CREEK

SDSM LOCALITY V2000-19

BOYER BAY MEMBER

SHARON SPRINGS FORMATION

PIERRE SHALE GROUP

CAMPANIAN STAGE

UPPER SENONIAN SUBEPOCH

UPPER UPPER GULF EPOCH

LATE CRETACEOUS

STEM: TETRAPODA GOODRICH, 1930

SUPERCLASS: AMNIOTA HAECKEL, 1866

CLASS: REPTILIA LAURENTI, 1768

SUBCLASS: DIAPSIDA OSBORN, 1903

INFRACLASS: NEODIAPSIDA BENTON, 1985

LEGION: LEPIDOSAUROMORPHA BENTON, 1983

SUBLEGION: LEPIDOSAURIA HAECKEL, 1866 (DUMERIL & BIBRON, 1839)

MAGNORDER: SQUAMATA, OPPEL, 1811

SUPERORDER: LACERTILIA OWEN, 1842

GRANDORDER: SCINCOGEKKONOMORPHA SUKHANOV, 1961

MICRORDER: SCINCOMORPHA CAMP, 1923

ORDER: ANGUIMORPHA FURBRINGER, 1900

SUBORDER: DIPLOGLOSSA COPE, 1864

INFRAORDER: THECAGLOSSA COPE, 1890

PARVORDER: MONSTERSAURIA NORELL & GAO, 1977

Superfamily: VARANOIDEA Gray, 1827 (sensu Camp, 1923)

Family: MOSASAURIDAE Gervais, 1853

Infrafamily: NATANIA

Subfamily: TYLOSAURINAE Williston, 1897

Cf. Tylosaurus sp

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