Polyonax

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title: "Polyonax" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["ceratopsidae", "dinosaur-genera", "maastrichtian-dinosaurs", "taxa-named-by-edward-drinker-cope", "fossil-taxa-described-in-1874", "dinosaurs-of-the-united-states"] description: "Extinct genus of dinosaurs" topic_path: "geography/united-states" source: "https://en.wikipedia.org/wiki/Polyonax" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Extinct genus of dinosaurs ::

| name = Polyonax | fossil_range = Late Cretaceous, | genus = Polyonax | parent_authority = Cope, 1874 | species = mortuarius | authority = Cope, 1874 | synonyms = * Agathaumas mortuarius (Cope, 1874) Hay, 1901

• Triceratops mortuarius (Cope, 1874) Kuhn, 1936

Polyonax (meaning "master over many") is a genus of ceratopsid dinosaur from the Late Cretaceous (late Maastrichtian) Denver Formation 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. Catalogued today as AMNH FR 3950, the type material included three dorsal vertebrae, limb bone material, and what are now known to be horn cores, from a subadult individual. Although it was briefly mixed up with hadrosaurs, and even considered to be a possible synonym of Trachodon, 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. 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. The most recent review listed it as an indeterminate ceratopsid.

It has sometimes been listed as a synonym of Agathaumas, or Triceratops.

Paleobiology

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

References

References

1. 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.
2. "American Museum of Natural History - Division of Paleontology - FR 3950".
3. Glut, D.F.. (1997). "Dinosaurs: The Encyclopedia". McFarland & Company.
4. Hatcher, J.B. (1902). The genus and species of the Trachodontidae (Hadrosauridae, Claosauridae) Marsh. ''Annals of the Carnegie Museum'' '''14'''(1):377-386.
5. 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
6. Dodson, P.. (1996). "The Horned Dinosaurs". Princeton University Press:Princeton, New Jersey.
7. 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.
8. [[Alfred Sherwood Romer. Romer, A.S.]] (1956). ''Osteology of the Reptiles''. University of Chicago Press:Chicago, 1-772. {{ISBN. 0-89464-985-X.
9. Lambert, D., and the Diagram Group. (1990). ''The Dinosaur Data Book''. Facts on File:Oxford, England, 320 p.

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