''Polyonax'' (meaning "master over many") was a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

ceratopsid Ceratopsidae (sometimes spelled Ceratopidae) is a family of ceratopsian dinosaurs including ''Triceratops'', '' Centrosaurus'', and '' Styracosaurus''. All known species were quadrupedal herbivores from the Upper Cretaceous. All but one species ar ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

from the late Maastrichtian-age

Upper Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

Denver Formation The Denver Formation is a geological formation that is present within the central part of the Denver Basin that underlies the Denver, Colorado, area. It ranges in age from latest Cretaceous ( Maastrichtian) to early Paleocene, and includes se ...

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

, United States. Founded upon poor remains, it is today regarded as a

dubious name In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

History

During an 1873 trip through the western US,

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of foss ...

and naturalist

Edward Drinker Cope Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontologist, comparative anatomist, herpetologist, and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy intereste ...

collected some fragmentary dinosaurian material which he soon named as a new genus.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. Catalogued today as AMNH FR 3950, the

type material In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes th ...

included three

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characterist ...

e, limb bone material, and what are now known to be horn cores, from a

subadult A juvenile is an individual organism that has not yet reached its adult form, sexual maturity or size. Juveniles can look very different from the adult form, particularly in colour, and may not fill the same Ecological niche, niche as the adult ...

individual. Although it was briefly mixed up with

hadrosaur Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which inclu ...

s, and even considered to be a possible synonym of ''

Trachodon ''Trachodon'' (meaning "rough tooth") is a dubious genus of hadrosaurid dinosaur based on teeth from the Campanian-age Upper Cretaceous Judith River Formation of Montana, U.S.Leidy, J. (1856). "Notice of remains of extinct reptiles and fishes, ...

'',Hatcher, J.B. (1902). The genus and species of the Trachodontidae (Hadrosauridae, Claosauridae) Marsh. ''Annals of the Carnegie Museum'' 14(1):377-386. 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.Hatcher, J.B., Marsh, O.C., and Lull, R.S. (1907). ''The Ceratopsia''. Government Printing Office:Washington, D.C., 300 pp. 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.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. . It has sometimes been listed as a synonym of ''

Agathaumas ''Agathaumas'' (; "great wonder") is a dubious genus of a large ceratopsid dinosaur that lived in Wyoming during the Late Cretaceous (late Maastrichtian stage, 66 million years ago). The name comes from grc, αγαν - 'much' and - 'wonder'. ...

'', Romer, A.S. (1956). ''Osteology of the Reptiles''. University of Chicago Press:Chicago, 1-772. . or ''

Triceratops ''Triceratops'' ( ; ) is a genus of herbivorous chasmosaurine ceratopsid dinosaur that first appeared during the late Maastrichtian stage of the Late Cretaceous period, about 68 million years ago in what is now North America. It is ...

''.Lambert, D., and the Diagram Group. (1990). ''The Dinosaur Data Book''. Facts on File:Oxford, England, 320 p.

Paleobiology

As a ceratopsid, ''Polyonax'' would have been a large,

quadruped Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuo ...

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthp ...

, with brow and nasal horns and a

neck frill A neck frill is the relatively extensive margin seen on the back of the heads of reptiles with either a bony support such as those present on the skulls of dinosaurs of the suborder Marginocephalia or a cartilaginous one as in the frill-neck ...

References

Chasmosaurines Late Cretaceous dinosaurs of North America Nomina dubia Fossil taxa described in 1874 Taxa named by Edward Drinker Cope Paleontology in Colorado Maastrichtian genus first appearances Maastrichtian genus extinctions Ornithischian genera {{ceratopsian-stub

History

Paleobiology

See also

References