Species: celer OSTROM, 1970
Etymology: Latin, celer, "swift"; in reference to the probable rapid-running capabilities indicated by the tibia-femur ratio.

Holotype: AMNH 3041

Locality: AMNH 33-1, SW 1/4, Sec. 26, T7N, R16E, Wheatland County, Montana.

Horizon: UNIT VII, 60 feet (18M0 below Unit VIII), Cloverly Formation.

Biostratigraphy:

Age: Cashenranchian, Aptian-Albian Stage, middle Gallic subepoch, lower Cretaceous Epoch, Early Cretaceous.

Material: A partial skeleton lacking skull.

Referred material:

Locality: YPM 63-19. NW 1/4, Sec. 28, T58N, R95W, 30 yards 927 m) NW of YPM 63-18, Big Horn County, Wyoming.

Horizon: Unit VII, 0 to 8 feet (0 to 2.4 m) above Unit VI, Cloverly Formation.

Biostratigraphy:

Age: Cashenranchian, Aptian-Albian Stage, middle Gallic subepoch, lower Cretaceous Epoch, Early Cretaceous.

Material:

YPM 5366:

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Species: chagyaensis (faunal list in ZHANG & LI, 1997) (nomen nudum)

Holotype:

Locality: Qandu, Zhang’yab, China.

Horizon: Laoran Formation.

Biostratigraphy:

Age: Early Cretaceous.

Material: