Coelosaurus tibia
Holotype tibia in 2013
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Dinosauria
Order: Saurischia
Family: Ornithomimidae
Genus: Coelosaurus
Leidy, 1865
Binomial name
Coelosaurus antiquus
Leidy, 1865

Ornithomimus antiquus
(Leidy, 1865)

Coelosaurus ("hollow lizard") is a species of theropod dinosaurs. It was named by Joseph Leidy in 1865 for two tibiae found in the Navesink Formation of New Jersey. The intended type species was named C. antiquus.

Coelosaurus antiquus


This species was later reclassified as a member of the genus Ornithomimus in 1979 by Donald Baird and John R. Horner as Ornithomimus antiquus,[1] and this was followed by some later researchers.[2] However, others have not followed this classification, and have noted that there is no justification for the classification of the New Jersey specimens in a genus known only from western North America. David Weishampel in 2004 considered "C." antiquus to be indeterminate among ornithomimosaurs, and therefore a nomen dubium.[3]

In 1979, Baird and Horner discovered that the name "Coelosaurus" was preoccupied by another dubious taxon (based on a single vertebra), named "Coelosaurus" by an anonymous author now known to be Richard Owen in 1854.[3]


  1. Baird D., and Horner, J., 1979, "Cretaceous dinosaurs of North Carolina", Brimleyana 2: 1-28
  2. Sullivan, (1997). "A juvenile Ornithomimus antiquus (Dinosauria: Theropoda: Ornithomimosauria), from the Upper Cretaceous Kirtland Formation (De-na-zin Member), San Juan Basin, New Mexico." New Mexico Geological Society Guidebook, 48th Field Conference, Mesozoic Geology and Paleontology of the Four Corners Region. 249-254.
  3. 3.0 3.1 Weishampel, D.B. (2004). "Another Look at the Dinosaurs of the East Coast of North America. En (Colectivo Arqueológico-Paleontológico Salense, Ed.)." Actas de las III Jornadas sobre Dinosaurios y su Entorno. 129-168. Salas de los Infantes, Burgos, España.