Ceratops (meaning "horn face") is a strange genus of ceratopsian dinosaur which lived during the Late Cretaceous. Its fossils have been found in the Judith River Formation in Montana. Although poorly known, Ceratops is important in the history of dinosaurs, since it is the type genus for which both the Ceratopsia and the Ceratopsidae have been named. The material was a little too poor to be confidently referred to better specimens, and Ceratops is sometimes considered a nomen dubium. More complete material recently found in Colorado may enable Ceratops to be reexamined (Trexler & Sweeney, 1995).
History[]
Illustration of the type specimen by Marsh
The first remains referred to Ceratops (an occipital condyle and a pair of horn cores) were found by John Bell Hatcher (1861-1904) in the summer of 1888 in the Judith River Formation of Montana. Hatcher was then an employee of Professor Othniel Charles Marsh who in the same year named the find the type species Ceratops montanus . The genus name is derived from the Greek κέρας, keras , "horn", and ὤψ, ops , "face". The species name refers to Montana. O. C. Marsh originally believed the animal to be similar to Stegosaurus, but with two horns on its head, a body length of seven to nine meters, horizontal plates on its back, and being bipedal. According to Marsh, this may have "represented a very strange appearance." In his illustration of the pair of horns, supposedly shown from behind, Marsh had changed the position of it and turned its outer face to its rear to make them point inwards.
The holotype, USNM 2411 , was found in a layer dating from the Campanian. It consists of the condyle and two nuclei of supraorbital horns twenty-two centimeters long. The right horn is attached to a part of the prefrontal bone. Marsh later referred two squamosal bones to the species, specimens USNM 4802 and USNM 2415. These however are probably from centrosaurus; have also been referred to Avaceratops .
In 1906 Richard Swann Lull noted that the name Ceratops had already been used by a bird, Ceratops . Rafinesque 1815, but this name had been an undescribed nomen nudum , so the name was still available in 1888. He still provisionally proposed a replacement name: Proceratops . Thus this is a more modern synonym for Ceratops .
In the early 20th century new finds made it increasingly difficult to distinguish the limited remains of Ceratops from those of several other related forms. Ceratops is therefore considered a nomen dubium . However, from time to time it is claimed that there are discoveries that, taking into account their origin, may have a probable connection with the holotype of Ceratops . .
In 1995, David Trexler and FG Sweeney noted that more complete material had been found in bedrock in Montana and could allow Ceratops to be reexamined . The site, known as the Mansfield Bone Bed, belongs to the same stratigraphic level in which the original Ceratops remains lay . These were initially interpreted as belonging to Styracosaurus , but previously what had been believed to be Styracosaurus spines were actually chasmosaurine orbital horns. Trexler and Sweeney noted that these horns closely resembled those of Ceratops , and could allow the genus to be rescued as a valid name. The ceratopsids in the bedrock were referred to the genus Albertaceratops , and were later reclassified into their own genus, Medusaceratops.
In 1999, Penkalski and Dodson concluded Ceratops is a nomen dubium because the material is too meager. They add that Avaceratops appears closely related and may even be a juvenile Ceratops but there is just not enough material to prove it.
Later species[]
In 1889 Marsh named a second species of Ceratops , Ceratops horridus . This would be changed almost immediately in a later paper to be renamed Triceratops horridus . Ceratops horridus is therefore the type species of Triceratops . In the same paper, Marsh renamed Bison alticornis, Marsh 1887, his misidentification of ceratopsian material for a giant bovid, into Ceratops alticornis . In 1890 Marsh renamed Hadrosaurus paucidens Marsh 1889 into Ceratops paucidens , but Hatcher's original evaluation of That this represented hadrosaurid material is probably correct.
In 1905, Hatcher renamed three species of Monoclonius to species of Ceratops , Monoclonius recurvicornis , Cope 1889, became Ceratops recurvicornis , Monoclonius belli , Lambe 1902, became Ceratops belli and Monoclonius canadensis , Lambe 1902, became Ceratops canadensis . C. belli later became the separate genus Chasmosaurus ; in 1925 William King Gregory concluded that Ceratops and Chasmosaurus were identical, but this was rejected by most researchers.
In 2005, remarkably well-preserved cranial and postcranial elements of a Juditian ceratopsian were discovered in Fergus County, Montana. Nicknamed "Judith", preliminary examination suggested a close affinity with C. montanus . The locality has been determined to be in or near the stratigraphic layer of C. montanus , and not many kilometers away. In 2016, the new animal was named Spiclypeus and the authors stated that it may be identical to Ceratops , which they consider a nomen dubium, or a growth stage of Albertaceratops.
Species[]
Type:
- Ceratops montanus Marsh 1888 (USNM 2411)
Others:
- C. (Bison) alticornis (Marsh 1887/1889). This was the famous pair of horn cores that were originally thought by Marsh to be from a giant bison. Marsh realized his error in 1889 and referred the horns to his Ceratops. Today they are recognized as the first Triceratops remains found and are, to date, the southernmost known Triceratops fossils. Even as Triceratops, it also is a nomen dubium.
- C. (Chasmosaurus) belli (Lambe 1902/Hatcher vide Stanton & Hatcher 1905)
- C. (Eoceratops) canadensis (Lambe 1902/Hatcher vide Stanton & Hatcher 1905)
- C. (Triceratops) horridus (Marsh 1889). This was the first intact ceratopsian skull discovered and led Marsh to realize the significance of the other specimens. As with the aforementioned species, it too is currently recognized as Triceratops.
- C. paucidens (Marsh 1889/1890); nomem dubium included with Lambeosaurus lambei
- C. (Chasmosaurus) recurvicornis (Cope 1890/Hatcher vide Stanton & Hatcher 1905)
Classification[]
Ceratops was placed in 1888 by Marsh in the family Ceratopsidae. It therefore belongs to Ceratopsia, the group of herbivorous dinosaurs with parrot-like beaks that lived in North America and Asia during the Cretaceous period, which ended approximately 66 million ago. of years. In 1919 the subfamily Ceratopsinae was named by Othenio Lothar Franz Anton Louis Abel, but this concept is problematic: Paul Sereno defined it as equivalent to Chasmosaurinae but other researchers prefer to restrict it to Ceratops itself because the phylogenetic relationships of this genus are uncertain.
Diet[]
Ceratops, like all Ceratopsians, was a herbivore. During the Cretaceous, flowering plants were "geographically limited on the landscape", and so it is likely that this dinosaur fed on the predominant plants of the era: ferns, cycads and conifers. It would have used its sharp Ceratopsian beak to bite off the leaves or needles.
Appearance in other media[]
Jurassic Park[]
Ceratops is one of the created dinosaurs that could be found in the nursery of the Jurassic Park Discovery Center of the Islands of Adventure.
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Read more Ceratops on Jurassic Park Wiki |
References[]
- Dodson, Peter; The Horned Dinosaurs (1996)
- Penkalski, P & Dodson, P (1999). "The morphology and systematics of Avaceratops, a primitive horned dinosaur from the Judith River Formation (Late Campanian) of Montana, with the description of a second skull.". Journal of Vertebrate Paleontology 19 (4): 692–711.
- Trexler D. & Sweeney F.G., 1995. Preliminary work on a recently discovered ceratopsian (Dinosauria: Ceratopsidae) bonebed from the Judith River Formation of Montana suggests the remains are of Ceratops montanus Marsh. J.Vert.Paleont. 15(3, Suppl.): 57A