Cionodon

Cionodon (meaning 'column tooth') is a dubious genus of hadrosaurid^[1] dinosaur from the Late Cretaceous. The type species, C. arctatus, was found in the Denver Formation of Lodge Pole Creek, Colorado and was formally described by Edward Drinker Cope in 1874 based on the holotype AMNH 3951, collected in 1873.^[2] It is a nomen dubium because it is based on very fragmentary remains. Two other species have since been described: Cionodon kysylkumensis (Riabinin, 1931), based on the holotype CCMGE 1/3760 (a set of vertebrae) from Uzbekistan,^[3] and Cionodon stenopsis (Cope, 1875), discovered in rocks from the Judith River Formation of Alberta, Canada in 1874.^[4] Although both are probably hadrosaurs,^[1] they are known only from fragmentary remains and Cionodon kysylkumensis has since been reclassified as Bactrosaurus kysylkumensis.^[3]

Cionodon Temporal range: Late Cretaceous, 70–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Vertebra of C. arctatus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	†Ornithischia
Clade:	†Ornithopoda
Family:	†Hadrosauridae
Genus:	†Cionodon Cope, 1874
Type species
†Cionodon arctatus Cope, 1874
Species
†C. arctatus Cope, 1874 (nomen dubium) †C. stenopsis Cope, 1875 (nomen dubium)
Synonyms
Cinodon (sic)

See also

• Timeline of hadrosaur research

References

1. J. R. Horner, D. B. Weishampel, and C. A. Forster. 2004. Hadrosauridae. In D. B. Weishampel, H. Osmolska, and P. Dodson (eds.), The Dinosauria (2nd edition). University of California Press, Berkeley 438-463
2. E. D. Cope. 1874. Report on the stratigraphy and Pliocene vertebrate paleontology of northern Colorado. Bulletin of the United States Geological and Geographical Survey of the Territories 1(1):9-22
3. A. N. Riabinin. 1931. Ostatki dinozavrov iz verkhnego mela nizov'ev r. Amu-Dar'i [On the dinosaurian remains from the Upper Cretaceous of the lower parts of the Amu-Daria River]. Zapiski Rossiyskogo Mineralogicheskogo Obshchestva 60(1):114-118
4. E. D. Cope. 1875. On the transition beds of the Saskatchewan district. Proceedings of the Academy of Natural Sciences of Philadelphia 27:2-3

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