Polyonax
Encyclopedia
Polyonax was a genus
of ceratopsid dinosaur
from the late Maastrichtian
-age Upper Cretaceous Denver Formation
of Colorado
, USA. Founded upon poor remains, it is today regarded as a dubious name
.
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
.
al herbivore
, with horns and a neck frill
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of ceratopsid dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
from the late Maastrichtian
Maastrichtian
The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...
-age Upper Cretaceous Denver Formation
Denver Formation
The Denver Formation is a geological formation in Colorado whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Ornithischians:-Saurischians:-References:...
of Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, USA. Founded upon poor remains, it is today regarded as a dubious name
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
.
History
During an 1873 trip through the western US, paleontologist and naturalistNatural history
Natural history is the scientific research of plants or animals, leaning more towards observational rather than experimental methods of study, and encompasses more research published in magazines than in academic journals. Grouped among the natural sciences, natural history is the systematic study...
Edward Drinker Cope
Edward Drinker Cope
Edward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen...
collected some fragmentary dinosaurian material which he soon named as a new genus. Catalogued today as AMNH FR 3950
American Museum of Natural History
The American Museum of Natural History , located on the Upper West Side of Manhattan in New York City, United States, is one of the largest and most celebrated museums in the world...
, the type material
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
included three dorsal
Dorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
vertebrae, limb bone material, and what are now known to be horn cores
Horn (anatomy)
A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn surrounding a core of living bone. True horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae...
, from a subadult
Juvenile (organism)
A juvenile is an individual organism that has not yet reached its adult form, sexual maturity or size. Juveniles sometimes look very different from the adult form, particularly in terms of their colour...
individual. Although it was briefly mixed up with hadrosaurs, and even considered to be a possible synonym of Trachodon
Trachodon
Trachodon is a dubious genus of hadrosaurid dinosaur based on teeth from the Campanian-age Upper Cretaceous Judith River Formation of Montana, U.S.A...
, it was recognized as a horned dinosaur in time for the first monograph
Monograph
A monograph is a work of writing upon a single subject, usually by a single author.It is often a scholarly essay or learned treatise, and may be released in the manner of a book or journal article. It is by definition a single document that forms a complete text in itself...
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
Agathaumas
Agathaumas is a dubious genus of a large ceratopsid dinosaur that lived in Wyoming during the Late Cretaceous . The name comes from Greek, αγαν - 'much' and θαυμα - 'wonder'...
, or Triceratops
Triceratops
Triceratops is a genus of herbivorous ceratopsid dinosaur which lived during the late Maastrichtian stage of the Late Cretaceous Period, around 68 to 65 million years ago in what is now North America. It was one of the last dinosaur genera to appear before the great Cretaceous–Paleogene...
.
Paleobiology
As a ceratopsid, Polyonax would have been a large, quadrupedQuadruped
Quadrupedalism is a form of land animal locomotion using four limbs or legs. An animal or machine that usually moves in a quadrupedal manner is known as a quadruped, meaning "four feet"...
al herbivore
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
, with horns and a neck frill
Neck frill
Neck frill is the popular term for 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-necked Lizard...
.