Allosaurus fragilis was named by Marsh (1877). Its type specimen is YPM 1930, a partial skeleton, and it is not a trace fossil. Its type locality is Felch Quarry 1, Garden Park (YPM), which is in a Kimmeridgian/Tithonian channel sandstone/claystone in the Morrison Formation of Colorado. It was considered monophyletic by Madsen (1976).
It was recombined as Labrosaurus lucaris by Marsh (1879); it was recombined as Antrodemus lucaris by Hay (1902); it was synonymized subjectively with Antrodemus valens by Steel (1970); it was misspelled as Allosaurus lucarius by Sauvage (1880); it was synonymized subjectively with Allosaurus fragilis by Holtz et al. (2004).
Creosaurus atrox was named by Marsh (1878). It is not extant. Its type specimen is YPM 1890. Its type locality is Reed's Quarry 1, Como Bluff (YPM), which is in a Kimmeridgian/Tithonian wet floodplain claystone in the Morrison Formation of Wyoming.
It was synonymized subjectively with Antrodemus valens by Steel (1970); it was recombined as Allosaurus atrox by Paul (1988) and Paul (1988); it was synonymized subjectively with Allosaurus fragilis by Holtz et al. (2004).
It was recombined as Allosaurus amplexus by Paul (1988); it was synonymized subjectively with Allosaurus fragilis by Holtz et al. (2004).
Labrosaurus ferox was named by Marsh (1884). Its type specimen is USNM 2315. Its type locality is Felch Quarry 1, Garden Park (YPM), which is in a Kimmeridgian/Tithonian channel sandstone/claystone in the Morrison Formation of Colorado.
It was synonymized subjectively with Antrodemus valens by Hay (1902) and Steel (1970); it was synonymized subjectively with Allosaurus fragilis by Holtz et al. (2004).
Poicilopleuron valens was named by Leidy (1870). Its type specimen is USNM 218, a set of vertebrae, and it is a 3D body fossil. Its type locality is Middle Park (USNM 218), which is in a Kimmeridgian/Tithonian pond horizon in the Morrison Formation of Colorado.
Allosaurus ferox was named by Marsh (1896). It is not extant. Its type specimen is YPM 1893. Its type locality is Reed's Quarry 14, Como Bluff (YPM), which is in a Kimmeridgian/Tithonian wet floodplain siltstone in the Morrison Formation of Wyoming.
It was synonymized subjectively with Allosaurus fragilis by Holtz et al. (2004).
Laelaps trihedrodon was named by Cope (1877). It is not extant. Its type specimen is AMNH (lost). Its type locality is Cope Quarry I, Cope's Nipple, which is in a Kimmeridgian/Tithonian dry floodplain mudstone in the Morrison Formation of Colorado.