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"Dryosaurus" grandis

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"Dryosaurus" grandis
Temporal range: Early Cretaceous, 112 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Ornithomimosauria
Genus: "Dryosaurus"
Species:
"D." grandis
Binomial name
"Dryosaurus" grandis
Lull, 1911
Synonyms

"Dryosaurus" grandis is a dubious species of ornithomimosaur dinosaur known from remains found in the Arundel Formation of Maryland.

Taxonomy

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Richard Swann Lull erected the species Dryosaurus grandis for foot elements from the Arundel Formation, including a phalanx and astragalus that had been previously assigned to "Allosaurus" medius Marsh, 1888.[1] Due to Gilmore's 1920 classification of Dryosaurus grandis as a member of the genus Ornithomimus, Marsh's 1890 name Ornithomimus grandis became secondarily preoccupied with Lull's term, necessitating the use of Ornithomimus affinis as a substitute.[2] However, the holotype specimen of Ornithomimus grandis comes from the Eagle Sandstone of Montana and is presumed lost, rendering Gilmore's action unnecessary.[3] Matthew and Brown (1922) assigned the species to Coelosaurus, as C. affinis.[4]

In his 1972 review of North American ornithomimosaurs, Russell (1972) noticed that "Dryosaurus" grandis was similar to the Asian Archaeornithomimus in having curved pedal unguals, so referred to it as Archaeornithomimus affinis. Smith and Galton (1990), however, claimed that the Arundel taxon could not be assigned beyond the level of Theropoda.[5] A 2016 paper by Chase Brownstein, however, confirmed Gilmore's assignment of "Dryosaurus" grandis to Ornithomimosauria, noting that the Arundel material is similar to Kinnareemimus and Nedcolbertia in the characteristics of the feet.[6]

References

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  1. ^ Lull, R.S. 1911. Systematic paleontology of the Lower Cretaceous deposits of Maryland: Vertebrata. Maryland Geological Survey: Lower Cretaceous 183-211.
  2. ^ Gilmore, C.W.. 1920. Osteology of the carnivorous Dinosauria in the United States National Museum, with special reference to the genera Antrodemus (Allosaurus) and Ceratosaurus. Bulletin of the United States National Museum 110:1-154.
  3. ^ Osborn, H.F. (1916). "Skeletal adaptations of Ornitholestes, Struthiomimus, Tyrannosaurus." Bulletin of the American Museum of Natural History, 35(43), 733-771.
  4. ^ Matthew, W.D. and B. Brown. 1922. The family Deinodontidae, with notice of a new genus from the Cretaceous of Alberta. Bulletin of the American Museum of Natural History 46(6):367-385.
  5. ^ Smith and Galton, 1990. Osteology of Archaeornithomimus asiaticus (Upper Cretaceous, Iren Dabasu Formation, People's Republic of China). Journal of Vertebrate Paleontology.
  6. ^ Brownstein, Chase Doran (2017). "Description of Arundel Clay ornithomimosaur material and a reinterpretation of Nedcolbertia justinhofmanni as an "Ostrich Dinosaur": Biogeographic implications". PeerJ. 5: e3110. doi:10.7717/peerj.3110. PMC 5345386. PMID 28286718.