Yamaceratops

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Yamaceratops
Temporal range: Late Cretaceous,
~Santonian
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Yamaceratops holotype skull.png
Holotype skull
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Ornithischia
Suborder: Ceratopsia
Infraorder: Neoceratopsia
Genus: Yamaceratops
Makovicky & Norell, 2006
Type species
Yamaceratops dorngobiensis
Makovicky & Norell, 2006
Juvenile MPC-D 100 553 Yamaceratops MPC-D 100 553 specimen.png
Juvenile MPC-D 100 553
Life restoration Yamaceratops BW.jpg
Life restoration

Yamaceratops is a genus of primitive ceratopsian that lived in Asia during the Late Cretaceous period in what is now the Javkhlant Formation. Initially, the rocks where it was found in were thought to be from the Early Cretaceous, but the age was reevaluated in 2009. [1] It was a relatively small dinosaur, reaching 50 cm (1.6 ft) in length and 2 kg (4.4 lb) in body mass. [2]

Contents

The type species, Yamaceratops dorngobiensis, was described by P. J. Makovicky and M. A. Norell in September, 2006. The authors consider the animal to have had an intermediate phylogenetic position between Liaoceratops and Archaeoceratops within Neoceratopia. Examination of the frill of Yamaceratops has convinced the authors that the frill was not used for display, and that the fossils "[hint] at a more complex evolutionary history for ceratopsian frills". Furthermore, Yamaceratops has been dated to either Aptian-early Albian, to even as early as mid-Barremian. This likely predated Archaeoceratops and Helioceratops , but not Liaoceratops. While there are many similarities between all four specimens, placing any into a specific family can be extremely difficult, and hotly contested between research teams. [3]

The genus name refers to Yama, a Tibetan Buddhist deity; the species name to the Eastern Gobi. The holotype IGM 100/1315 consists of a partial skull; other material has been found in 2002 and 2003 and has been ascribed to the genus. [3]

A fossilized embryo found within an ornithischian eggshell from sediments where Yamaceratops is common, was in 2008 referred to this genus. [4] However, in 2015 it was reidentified as a bird embryo. [5]

In 2020 Minyoung Son and colleagues reported a juvenile specimen of Yamaceratops found in 2014 at the Khugenetjavkhlant ("Khugenslavkhant") locality. [6] This probably three years old specimen, MPC-D 100/553, was described in detail in 2022. [7]

See also

Related Research Articles

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Protoceratops is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous, around 75 to 71 million years ago. The genus Protoceratops includes two species: P. andrewsi and the larger P. hellenikorhinus. The former was described in 1923 with fossils from the Mongolian Djadokhta Formation, and the latter in 2001 with fossils from the Chinese Bayan Mandahu Formation. Protoceratops was initially believed to be an ancestor of ankylosaurians and larger ceratopsians, such as Triceratops and relatives, until the discoveries of other protoceratopsids. Populations of P. andrewsi may have evolved into Bagaceratops through anagenesis.

<span class="mw-page-title-main">Ceratopsia</span> Extinct suborder of Dinosaurs

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<i>Liaoceratops</i> Extinct genus of dinosaurs

Liaoceratops, meaning "Liaoning horned face", is a ceratopsian dinosaur believed to be an early relative of the horned ceratopsids. It lived in the Early Cretaceous, 126 million years ago. It was discovered in China by a team of American and Chinese scientists. Liaoceratops was much smaller than its later relatives, but offers a glimpse into the early evolution of this group of dinosaurs.

<span class="mw-page-title-main">Protoceratopsidae</span> Extinct family of ceratopsians

Protoceratopsidae is a family of basal (primitive) ceratopsians from the Late Cretaceous period. Although ceratopsians have been found all over the world, protoceratopsids are only definitively known from Cretaceous strata in Asia, with most specimens found in China and Mongolia. As ceratopsians, protoceratopsids were herbivorous, with constantly replacing tooth batteries made for slicing through plants and a hooked beak for grabbing them. Protoceratopsids were small ceratopsians around 1-2.5 m in length. Their bony frill and horns were much smaller than more derived members of Ceratopsia, such as ceratopsids.

<i>Bagaceratops</i> Protoceratopsid dinosaur genus from the Late Cretaceous

Bagaceratops is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous, around 72 to 71 million years ago. Bagaceratops remains have been reported from the Barun Goyot Formation and Bayan Mandahu Formation. One specimen may argue the possible presence of Bagaceratops in the Djadochta Formation.

Asiaceratops is a genus of herbivorous ceratopsian dinosaur. It lived during the Early-Late Cretaceous. The type species, A. salsopaludalis is known from Uzbekistan, while A. sulcidens is known from China and Mongolia.

<i>Breviceratops</i> Protoceratopsid dinosaur genus from the Late Cretaceous

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<i>Udanoceratops</i> Leptoceratopsid dinosaur genus from the Late Cretaceous

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<span class="mw-page-title-main">Djadochta Formation</span> Geologic formation in Mongolia

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<i>Minotaurasaurus</i> Extinct genus of dinosaurs

Minotaurasaurus is a monospecific genus of ankylosaurid dinosaur that lived in Mongolia during the Late Cretaceous in what is now the Djadochta Formation. The type and only species, Minotaurasaurus ramachandrani, is known from two skulls, a cervical vertebra and a cervical half ring. It was named and described in 2009 by Clifford Miles and Clark Miles. The first fossils of Minotaurasaurus were illegally exported out of Mongolia.It has been suggested to be a synonym of Tarchia but more recent publications consider it as a distinct genus.

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<span class="mw-page-title-main">Timeline of ceratopsian research</span>

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<span class="mw-page-title-main">Javkhlant Formation</span> Geological formation in Mongolia

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<i>Jaculinykus</i> Genus of alvarezsaurid dinosaurs

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References

  1. Eberth, David A.; Kobayashi, Yoshitsugu; Lee, Yuong-Nam; Mateus, Octávio; Therrien, François; Zelenitsky, Darla K.; Norell, Mark A. (2009). "Assignment of Yamaceratops dorngobiensis and associated redbeds at Shine Us Khudag (eastern Gobi, Dorngobi Province, Mongolia) to the restricted Javkhlant Formation (Upper Cretaceous)". Journal of Vertebrate Paleontology. 29 (1): 295–302. doi:10.1080/02724634.2009.10010384. S2CID   197540125.
  2. Paul, Gregory S. (2016). The Princeton Field Guide to Dinosaurs. Princeton University Press. p. 279. ISBN   978-1-78684-190-2. OCLC   985402380.
  3. 1 2 Makovicky, Peter J.; Norell, Mark A. (2006). "Yamaceratops dorngobiensis, a new primitive ceratopsian (Dinosauria: Ornithischia) from the Cretaceous of Mongolia" (PDF). American Museum Novitates (3530): 1–42. doi:10.1206/0003-0082(2006)3530[1:YDANPC]2.0.CO;2.
  4. Balanoff, A.M.; Norell, M.A.; Grellet-Tinner, G.; Lewin, M.R. (2008). "Digital preparation of a probable neoceratopsian preserved within an egg, with comments on microstructural anatomy of ornithischian eggshells". Naturwissenschaften. 95 (6): 493–500. Bibcode:2008NW.....95..493B. doi:10.1007/s00114-008-0347-2. PMID   18347769. S2CID   6421080.
  5. Varricchio D.J., Balanoff A.M., Norell M.A., 2015, "Reidentification of Avian Embryonic Remains from the Cretaceous of Mongolia", PLoS ONE10(6): e0128458
  6. Son, M.; Lee, Y.-N.; Zorit, B.; Park, J.-Y.; Lee, S.; Kim, S.-H.; Lee, K.-Y. (2020). "A juvenile Yamaceratops dorngobiensis (Ornithischia, Ceratopsia) from the Upper Cretaceous Javkhlant Formation of Mongolia" (PDF). Journal of Vertebrate Paleontology. Program and Abstracts: 311.
  7. Son, M.; Lee, Y.-M.; Zorigt, B.; Kobayashi, Y.; Park, J.-Y.; Lee, S.; Kim, S.-H.; Lee, K. Y. (2022). "A new juvenile Yamaceratops (Dinosauria, Ceratopsia) from the Javkhlant Formation (Upper Cretaceous) of Mongolia". PeerJ. 10: e13176. doi: 10.7717/peerj.13176 . PMC   8992648 . PMID   35402094.