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Allosaurus fragilis Marsh 1877 (allosaurid)

Reptilia - Avetheropoda - Allosauridae

Alternative combinations: Allosaurus agilis, Antrodemus fragilis

Synonyms: Allosaurus amplexus Cope 1878, Allosaurus atrox Marsh 1878, Allosaurus ferox Marsh 1896, Allosaurus lucaris Marsh 1878, Allosaurus lucarius Marsh 1878, Antrodemus lucaris Marsh 1878, Antrodemus valens Leidy 1870, Creosaurus atrox Marsh 1878, Dryptosaurus trihedridon Cope 1877, Dryptosaurus trihedrodon Cope 1877, Epanterias amplexus Cope 1878, Labrosaurus ferox Marsh 1884, Labrosaurus lucaris Marsh 1878, Laelaps trihedrodon Cope 1877, Poicilopleuron valens Leidy 1870, Saurophagus maximus Ray 1941

Full reference: O. C. Marsh. 1877. Notice of new dinosaurian reptiles from the Jurassic formation. American Journal of Science and Arts 14:514-516

Belongs to Allosaurus according to M. T. Carrano et al. 2012

Sister taxa: Allosaurus europaeus, Allosaurus jimmadseni, Camptonotus amplus, Labrosaurus sulcatus

Type specimens:

  • Allosaurus fragilis: YPM 1930, a partial skeleton. Its type locality is Felch Quarry 1, Garden Park (YPM) (=Marsh Quarry; =Marsh-Felch Quarry), which is in a Kimmeridgian/Tithonian channel sandstone/claystone in the Morrison Formation of Colorado.
  • Allosaurus ferox: YPM 1893. Its type locality is Quarry 14, Como Bluff (YPM), which is in a Kimmeridgian/Tithonian wet floodplain siltstone in the Morrison Formation of Wyoming.
  • Allosaurus lucaris: YPM 1931. Its type locality is Quarry 3, Como Bluff (YPM), which is in a Kimmeridgian/Tithonian wet floodplain mudstone in the Morrison Formation of Wyoming.
  • Creosaurus atrox: YPM 1890, a partial skeleton. Its type locality is Quarry 1, Como Bluff (YPM), which is in a Kimmeridgian/Tithonian wet floodplain claystone in the Morrison Formation of Wyoming.
  • Epanterias amplexus: AMNH 5767. Its type locality is Cope Quarry III, Cope's Nipple, which is in a Tithonian dry floodplain mudstone in the Morrison Formation of Colorado.
  • Labrosaurus ferox: USNM 2315. Its type locality is Felch Quarry 1, Garden Park (YPM) (=Marsh Quarry; =Marsh-Felch Quarry), which is in a Kimmeridgian/Tithonian channel sandstone/claystone in the Morrison Formation of Colorado.
  • Laelaps trihedrodon: AMNH (lost), a mandible. 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.
  • Poicilopleuron valens: USNM 218, a set of vertebrae. Its type locality is Middle Park (USNM 218), which is in a Kimmeridgian/Tithonian pond horizon in the Morrison Formation of Colorado.
  • Saurophagus maximus: Its type locality is OMNH Quarry 1, Kenton (OMNH V92), which is in a Kimmeridgian/Tithonian wet floodplain claystone/sandstone in the Morrison Formation of Oklahoma.

Ecology: ground dwelling carnivore

Average measurements (in mm): coracoid length 120.0, femur length 888.6, femur circumference 323.1, fibula length 677.6, fibula circumference 113.8, humerus 360.8 x 118.0, radius 222.0 x 20.0, scapula 652.0 x 175.0, tibia length 746.0, tibia circumference 278.0, ulna 263.0 x 24.0

Estimated body mass: 1.40 tons based on femur length