Arrhinoceratops (meaning "no nose-horn face", derived from the Ancient Greek"a-/α-" "no", rhis/ῥίς "nose" "keras/κέρας" "horn", "-ops/ὤψ" "face") is a genus of herbivorous ceratopsiandinosaur. The name was coined as its original describer concluded it was special because the nose-horn was not a separate bone, however further analysis revealed this was based on a misunderstanding.[1] It lived during the latest Campanian/earliest Maastrichtian stage of the Late Cretaceous, predating its famous relative Triceratops by a few million years, although it was contemporary with Anchiceratops.[1] Its remains have been found in Canada.[1]
Parks named the type speciesArrhinoceratops brachyops. The generic name is derived from Greek α~, "without", ῥίς, rhis, "nose", κέρας, keras, "horn", and ὤψ, ops, "face" as Parks had established that no separate nose-horn was present. The specific name means "short-faced" from Greek βραχύς, brachys, "short".[2]
The holotype is ROM 796 (earlier ROM 5135), which was found in a layer of the Horseshoe Canyon Formation dating from the latest Campanian or perhaps earliest Maastrichtian. It consists of the original skull.
Other material from Utah, found in the 1930s, was posthumously named Arrhinoceratops? utahensis by Charles Whitney Gilmore in 1946. It is based on holotype USNM 15583. The question mark indicates that Gilmore himself had doubts about the identification.[3] In 1976, Douglas A. Lawson transferred the species to Torosaurus, as a Torosaurus utahensis.[4][5]
Apart from the holotype skull little fossil material of Arrhinoceratops brachyops has been found. In 1981 Helen Tyson in a revision of the genus, provisionally referred specimen ROM 1439,[6] but in 2007 Andrew Farke moved this to Torosaurus.[7]
Description
Restoration
Since this dinosaur is known only from its skull, scientists have few data about its overall anatomy. The skull, as restored, features a broad, square, neck frill with two oval shaped openings.[1] The frill is deeply veined on both the top and the underside by arterial grooves. The sides of the frill are adorned by about nine osteoderms. The rear edge of the frill is lightly scalloped. The left squamosal in the frill side of the holotype shows a pathological opening, perhaps the result of a wound. Its brow horns were moderately long, but its nose horn was shorter and blunter than most ceratopids. The snout is short and high.[1] Its body is assumed to be typical of the Ceratopsidae. Based on the skull some popular-science books estimate the body length to be 6 m (20 ft) long when fully grown.[1] In 2010, Gregory S. Paul estimated its length at 4.5 metres (15 ft), its weight at 1.3 tonnes (2,900 lb).[8]
Already Richard Swann Lull had in 1933 been politely critical of Parks' original description,[9] and Tyson discovered that Parks, an entomologist, had made many mistakes. The most notable of these was that the very trait the genus was named after, the lack of a separate ossification or os epinasale for the nose-horn, is in fact normal for the ceratopids, in which group this horn is an outgrowth of the nasal bone, not a distinct element. Other incorrect observations by Parks included the conclusion that the os rostrale, the bone core of the upper beak, directly touched the nasals instead of being separated from them by the premaxillae; a presumed anterior process of the jugal touching the premaxilla; and thinking that the interparietal bar of the frill presented a separate skeletal element, an os interparietale.[6]
Phylogeny
Arrhinoceratops was by Parks placed within the Ceratopsia (this name is Ancient Greek for "horned faces"), a group of herbivorous dinosaurs with parrot-like beaks which thrived in North America and Asia during the Cretaceous Period, which ended roughly 66 million years ago. In 1930 Lori Russell refined this to the Ceratopsidae.[10] Tyson concluded it was closely related to Torosaurus, probably even its direct ancestor.[1][6]
Arrhinoceratops lived in a wet coast-land with warm summers but cool winters. It was likely preyed upon by Albertosaurus.[8]
Arrhinoceratops, 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. Its habitat was densely forested.[8]
^ abcdefg"Arrhinoceratops." In: Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B. The Age of Dinosaurs. Publications International, LTD. p. 127. ISBN0-7853-0443-6.
^ abParks, W.A. (1925). "Arrhinoceratops brachyops, a new genus and species of Ceratopsia from the Edmonton Formation of Alberta". University of Toronto Studies, Geology Series 19:1-15
^C.W. Gilmore, 1946, "Reptilian fauna of the North Horn Formation of central Utah", United States Department of the Interior Geological Survey Professional Paper 210-C: 29-53
^D.A. Lawson, 1976, "Tyrannosaurus and Torosaurus, Maestrichtian dinosaurs from Trans-Pecos, Texas", Journal of Paleontology50(1): 158-164
^Hunt, R.K. and Lehman, T.M. (2008). "Attributes of the ceratopsian dinosaur Torosaurus, and new material from the Javelina Formation (Maastrichtian) of Texas". Journal of Paleontology 82(6): 1127-1138.
^ abcTyson, H., 1981, "The structure and relationships of the horned dinosaur Arrhinoceratops Parks (Ornithischia: Ceratopsidae)", Canadian Journal of Earth Sciences18: 1241-1247
^Farke, A.A., 2007, "Cranial osteology and phylogenetic relationships of the chasmosaurine ceratopsid Torosaurus latus", pp 235-257 in: K. Carpenter (ed.), Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs, Bloomington, Indiana University Press
^ abcPaul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 267
^R.S. Lull, 1933, "A revision of the Ceratopsia or horned dinosaurs", Memoirs of the Peabody Museum of Natural History3(3): 1-175
^L.S. Russell, 1930, "Upper Cretaceous dinosaur faunas of North America", Proceedings of the American Philosophical Society69(4): 133-159
^P. Dodson and P.J. Currie, 1990, "Neoceratopsia". In: D.B. Weishampel, H. Osmolska, and P. Dodson (eds.), The Dinosauria. First Edition. University of California Press, Berkeley, pp 593-618
^Scott D. Sampson; Mark A. Loewen; Andrew A. Farke; Eric M. Roberts; Catherine A. Forster; Joshua A. Smith & Alan L. Titus (2010). Stepanova, Anna (ed.). "New Horned Dinosaurs from Utah Provide Evidence for Intracontinental Dinosaur Endemism". PLOS ONE. 5 (9): e12292. Bibcode:2010PLoSO...512292S. doi:10.1371/journal.pone.0012292. PMC2929175. PMID 20877459.
References
Dodson, P. (1996). The Horned Dinosaurs. Princeton University Press, Princeton, New Jersey, pp. xiv-346
December 29, 2022
arrhinoceratops, meaning, nose, horn, face, derived, from, ancient, greek, rhis, ῥίς, nose, keras, κέρας, horn, ὤψ, face, genus, herbivorous, ceratopsian, dinosaur, name, coined, original, describer, concluded, special, because, nose, horn, separate, bone, how. Arrhinoceratops meaning no nose horn face derived from the Ancient Greek a a no rhis ῥis nose keras keras horn ops ὤps face is a genus of herbivorous ceratopsian dinosaur The name was coined as its original describer concluded it was special because the nose horn was not a separate bone however further analysis revealed this was based on a misunderstanding 1 It lived during the latest Campanian earliest Maastrichtian stage of the Late Cretaceous predating its famous relative Triceratops by a few million years although it was contemporary with Anchiceratops 1 Its remains have been found in Canada 1 ArrhinoceratopsTemporal range Early Maastrichtian 70 6 70 Ma PreꞒ Ꞓ O S D C P T J K Pg N Arrhinoceratops brachyops at the Royal Ontario MuseumScientific classificationKingdom AnimaliaPhylum ChordataClade DinosauriaOrder OrnithischiaSuborder CeratopsiaFamily CeratopsidaeSubfamily ChasmosaurinaeGenus ArrhinoceratopsParks 1925Species A brachyopsBinomial name Arrhinoceratops brachyopsParks 1925 Contents 1 Discoveries and species 2 Description 3 Phylogeny 4 Paleobiology 5 See also 6 Footnotes 7 ReferencesDiscoveries and species EditDescribed by William Arthur Parks in 1925 Arrhinoceratops is known from a partially crushed slightly distorted skull which lacked the lower jaws The remains were collected from the Neill s Ranch site along the Red Deer River in Alberta by a 1923 expedition from the University of Toronto 2 Parks named the type species Arrhinoceratops brachyops The generic name is derived from Greek a without ῥis rhis nose keras keras horn and ὤps ops face as Parks had established that no separate nose horn was present The specific name means short faced from Greek braxys brachys short 2 The holotype is ROM 796 earlier ROM 5135 which was found in a layer of the Horseshoe Canyon Formation dating from the latest Campanian or perhaps earliest Maastrichtian It consists of the original skull Other material from Utah found in the 1930s was posthumously named Arrhinoceratops utahensis by Charles Whitney Gilmore in 1946 It is based on holotype USNM 15583 The question mark indicates that Gilmore himself had doubts about the identification 3 In 1976 Douglas A Lawson transferred the species to Torosaurus as a Torosaurus utahensis 4 5 Apart from the holotype skull little fossil material of Arrhinoceratops brachyops has been found In 1981 Helen Tyson in a revision of the genus provisionally referred specimen ROM 1439 6 but in 2007 Andrew Farke moved this to Torosaurus 7 Description Edit Restoration Since this dinosaur is known only from its skull scientists have few data about its overall anatomy The skull as restored features a broad square neck frill with two oval shaped openings 1 The frill is deeply veined on both the top and the underside by arterial grooves The sides of the frill are adorned by about nine osteoderms The rear edge of the frill is lightly scalloped The left squamosal in the frill side of the holotype shows a pathological opening perhaps the result of a wound Its brow horns were moderately long but its nose horn was shorter and blunter than most ceratopids The snout is short and high 1 Its body is assumed to be typical of the Ceratopsidae Based on the skull some popular science books estimate the body length to be 6 m 20 ft long when fully grown 1 In 2010 Gregory S Paul estimated its length at 4 5 metres 15 ft its weight at 1 3 tonnes 2 900 lb 8 Already Richard Swann Lull had in 1933 been politely critical of Parks original description 9 and Tyson discovered that Parks an entomologist had made many mistakes The most notable of these was that the very trait the genus was named after the lack of a separate ossification or os epinasale for the nose horn is in fact normal for the ceratopids in which group this horn is an outgrowth of the nasal bone not a distinct element Other incorrect observations by Parks included the conclusion that the os rostrale the bone core of the upper beak directly touched the nasals instead of being separated from them by the premaxillae a presumed anterior process of the jugal touching the premaxilla and thinking that the interparietal bar of the frill presented a separate skeletal element an os interparietale 6 Phylogeny EditArrhinoceratops was by Parks placed within the Ceratopsia this name is Ancient Greek for horned faces a group of herbivorous dinosaurs with parrot like beaks which thrived in North America and Asia during the Cretaceous Period which ended roughly 66 million years ago In 1930 Lori Russell refined this to the Ceratopsidae 10 Tyson concluded it was closely related to Torosaurus probably even its direct ancestor 1 6 Modern research indicates that Arrhinoceratops is a member of the Chasmosaurinae 11 Cladistic analyses recover it close to Anchiceratops Restoration of the head The following cladogram shows the phylogeny of Arrhinoceratops according to a study by Scott Sampson e a in 2010 12 Ceratopidae Centrosaurinae Chasmosaurinae ChasmosaurusMojoceratopsAgujaceratopsUtahceratopsPentaceratopsCoahuilaceratopsKosmoceratopsVagaceratopsAnchiceratopsArrhinoceratopsOjoceratopsEotriceratopsTorosaurusNedoceratopsTriceratopsPaleobiology EditArrhinoceratops lived in a wet coast land with warm summers but cool winters It was likely preyed upon by Albertosaurus 8 Arrhinoceratops 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 Its habitat was densely forested 8 See also Edit Dinosaurs portalTimeline of ceratopsian researchFootnotes Edit a b c d e f g Arrhinoceratops In Dodson Peter amp Britt Brooks amp Carpenter Kenneth amp Forster Catherine A amp Gillette David D amp Norell Mark A amp Olshevsky George amp Parrish J Michael amp Weishampel David B The Age of Dinosaurs Publications International LTD p 127 ISBN 0 7853 0443 6 a b Parks W A 1925 Arrhinoceratops brachyops a new genus and species of Ceratopsia from the Edmonton Formation of Alberta University of Toronto Studies Geology Series 19 1 15 C W Gilmore 1946 Reptilian fauna of the North Horn Formation of central Utah United States Department of the Interior Geological Survey Professional Paper 210 C 29 53 D A Lawson 1976 Tyrannosaurus and Torosaurus Maestrichtian dinosaurs from Trans Pecos Texas Journal of Paleontology 50 1 158 164 Hunt R K and Lehman T M 2008 Attributes of the ceratopsian dinosaur Torosaurus and new material from the Javelina Formation Maastrichtian of Texas Journal of Paleontology 82 6 1127 1138 a b c Tyson H 1981 The structure and relationships of the horned dinosaur Arrhinoceratops Parks Ornithischia Ceratopsidae Canadian Journal of Earth Sciences 18 1241 1247 Farke A A 2007 Cranial osteology and phylogenetic relationships of the chasmosaurine ceratopsid Torosaurus latus pp 235 257 in K Carpenter ed Horns and Beaks Ceratopsian and Ornithopod Dinosaurs Bloomington Indiana University Press a b c Paul G S 2010 The Princeton Field Guide to Dinosaurs Princeton University Press p 267 R S Lull 1933 A revision of the Ceratopsia or horned dinosaurs Memoirs of the Peabody Museum of Natural History 3 3 1 175 L S Russell 1930 Upper Cretaceous dinosaur faunas of North America Proceedings of the American Philosophical Society 69 4 133 159 P Dodson and P J Currie 1990 Neoceratopsia In D B Weishampel H Osmolska and P Dodson eds The Dinosauria First Edition University of California Press Berkeley pp 593 618 Scott D Sampson Mark A Loewen Andrew A Farke Eric M Roberts Catherine A Forster Joshua A Smith amp Alan L Titus 2010 Stepanova Anna ed New Horned Dinosaurs from Utah Provide Evidence for Intracontinental Dinosaur Endemism PLOS ONE 5 9 e12292 Bibcode 2010PLoSO 512292S doi 10 1371 journal pone 0012292 PMC 2929175 PMID 20877459 References EditDodson P 1996 The Horned Dinosaurs Princeton University Press Princeton New Jersey pp xiv 346 Retrieved from https en wikipedia org w index php title Arrhinoceratops amp oldid 1120968549, wikipedia, wiki, book, books, library,
