Polyonax

Polyonax; Temporal range: Late Cretaceous, 66 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	†Ornithischia
Family:	†Ceratopsidae
Genus:	†Polyonax; Cope, 1874
Species:	†P. mortuarius
Binomial name
	†Polyonax mortuarius; Cope, 1874
Synonyms
	Agathaumas mortuarius ; (Cope, 1874) Hay, 1901; Triceratops mortuarius ; (Cope, 1874) Kuhn, 1936;

Polyonax (meaning "master over many") was a genus of ceratopsid dinosaur from the late Maastrichtian-age Upper Cretaceous Denver Formation^{[citation needed]} of Colorado, United States. Founded upon poor remains, it is today regarded as a dubious name.

History

During an 1873 trip through the western US, paleontologist and naturalist Edward Drinker Cope collected some fragmentary dinosaurian material which he soon named as a new genus.^[1] Catalogued today as AMNH FR 3950,^[2] the type material included three dorsal vertebrae, limb bone material, and what are now known to be horn cores, from a subadult individual.^[3] Although it was briefly mixed up with hadrosaurs, and even considered to be a possible synonym of Trachodon,^[4] it was recognized as a horned dinosaur in time for the first monograph on horned dinosaurs (1907), wherein it was regarded as based on indeterminate material.^[5] Today, the name is used as little more than a historical curiosity, as it dates from a time before horned dinosaurs were known to exist.^[6] The most recent review listed it as an indeterminate ceratopsid.^[7]

It has sometimes been listed as a synonym of Agathaumas,^[8] or Triceratops.^[9]

Paleobiology

As a ceratopsid, Polyonax would have been a large, quadrupedal herbivore, with brow and nasal horns and a neck frill.^[7]

References

^ Cope, E.D. (1874). Report on the stratigraphy and Pliocene vertebrate paleontology of northern Colorado. Bulletin of the U.S. Geological and Geographical Survey of the Territories. 9:9-28.
^ "American Museum of Natural History - Division of Paleontology - FR 3950".
^ Glut, D.F. (1997). "Polyonax". Dinosaurs: The Encyclopedia. McFarland & Company. pp. 723–724. ISBN 978-0-89950-917-4.
^ Hatcher, J.B. (1902). The genus and species of the Trachodontidae (Hadrosauridae, Claosauridae) Marsh. Annals of the Carnegie Museum 14(1):377-386.
^ Hatcher, J.B., Marsh, O.C., and Lull, R.S. (1907). The Ceratopsia. Government Printing Office:Washington, D.C., 300 pp. ISBN 0-405-12713-8
^ Dodson, P. (1996). The Horned Dinosaurs. Princeton University Press:Princeton, New Jersey. ISBN 978-0-691-02882-8.
^ ^a ^b Dodson, P., Forster, C.A., and Sampson, S.D. (2004). Ceratopsidae. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria (second edition). University of California Press:Berkeley, 494-513. ISBN 0-520-24209-2.
^ Romer, A.S. (1956). Osteology of the Reptiles. University of Chicago Press:Chicago, 1-772. ISBN 0-89464-985-X.
^ Lambert, D., and the Diagram Group. (1990). The Dinosaur Data Book. Facts on File:Oxford, England, 320 p.