MONTANA
ST. MARY RIVER FORMATION
LOWER MAASTRICHTIAN STAGE
UPPER SENONIAN SUBEPOCH
UPPER GULF EPOCH
LATE CRETACEOUS
STEM: TETRAPODA GOODRICH, 1930
SUPERCLASS: AMNIOTA HAECKEL, 1866
CLASS: REPTILIA LAURENTI, 1768
SUBCLASS: DIAPSIDA OSBORN, 1904
SUPERLEGION: NEODIAPSIDA BENTON, 1985
LEGION: ARCHOSAUROMORPHA HUENE, 1946
SUPERCOHORT CHORISTODERA NOVA
ORDER: CHORISTODERA COPE, 1876
Incertae sedis
Gen. sp. Indet.
SUPERCOHORT: CRUROTARSI SERENO & ARCUCCI, 1990
COHORT: CROCODYLOTARSI BENTON & CLARK, 1988
MAGNORDER: SUCHIA KREBS, 1974
SUPERORDER: CROCODYLOMORPHA WALKER, 1968
GRANDORDER: CROCODILIFORMES HAY, 1930
MICRORDER: MESOEUROCROCODYLIA WHETSTONE & WHYBROW, 1983
ORDER: EUSUCHIA emend HUXLEY, 1875
INFRAORDER: CROCODYLIA emend GMELIN, 1877
Incerate sedis
Gen. sp. indet.
SUBLEGION: DINOSAUROMORPHA BENTON & NORMAN IN BENTON, 1985
INFRALEGION: DINOSAURIFORMES NOVAS, 1992
SUPERCOHORT: DINOSAURIA OWEN, 1842
COHORT: THEROPODA EMEND MARSH, 1881
AVEPODA PAUL, 2002
SUPERORDER: NEOTHEROPODA BAKKER, 1986
GRANDORDER: TETANURAE GAUTHIER, 1986
MICRORDER: COELUROSAURIA HUENE, 1914
ORDER: MANIRAPTORFORMES HOLTZ, 1996
AVETHEROPODA PAUL, 2001
SUBORDER: COELURIA MARSH, 1881
Superfamily: TYRANNOSAUROIDEA Osborn, 1906 (sensu Bonaparte et. al., 1990)
Family: TYRANNOSAURIDAE Osborn, 1906
Gen. sp indet.
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