Editing Protoceratops (section)

===Species and synonyms===
[[File:Protoceratops hellenikorhinus holotype skull.jpg|thumb|Holotype skull of ''P. hellenikorhinus'' at the [[Inner Mongolia Museum]]]]
Protoceratopsid remains were recovered in the 1970s from the Khulsan locality of the [[Barun Goyot Formation]], Mongolia, during the work of several Polish-Mongolian paleontological expeditions. In 1975, Polish paleontologists [[Teresa Maryańska]] and [[Halszka Osmólska]] described a second species of ''Protoceratops'' which they named ''P. kozlowskii''. This new species was based on the Khulsan material, mostly consisting of juvenile skull specimens. The specific name, ''kozlowskii'', is in tribute to the Polish paleontologist [[Roman Kozłowski]]. They also named the new genus and species of protoceratopsid ''[[Bagaceratops rozhdestvenskyi]]'', known from specimens of the nearby Hermiin Tsav locality.<ref name=Mary1975>{{cite journal|last1=Maryańska|first1=T.|last2=Osmólska|first2=H.|date=1975|title=Protoceratopsidae (Dinosauria) of Asia|journal=Palaeontologia Polonica|volume=33|page=134−143|url=http://palaeontologia.pan.pl/Archive/1975-33_133-181_36-50.pdf|access-date=10 June 2022|archive-date=21 September 2018|archive-url=https://web.archive.org/web/20180921083509/http://palaeontologia.pan.pl/Archive/1975-33_133-181_36-50.pdf|url-status=dead}}</ref> In 1990 the Russian paleontologist [[Sergei Mikhailovich Kurzanov]] referred additional material from Hermiin Tsav to ''P. kozlowskii''. However, he noted that there were enough differences between ''P. andrewsi'' and ''P. kozlowskii'', and erected the new genus and combination ''[[Breviceratops kozlowskii]]''.<ref>{{cite journal |last1=Kurzanov|first1=S. M.|date=1990|title=Новый род протоцератопсид из позднего мела Монголии|trans-title=A new Late Cretaceous protoceratopsid genus from Mongolia|journal=Paleontological Journal|number=4|pages=91–97|language=ru|url=https://www.geokniga.org/bookfiles/geokniga-paleontologicaljournal1990-4.pdf}}</ref> Though ''Breviceratops'' has been regarded as a [[synonym]] and juvenile stage of ''Bagaceratops'',<ref name=Sereno2000>{{cite book|last1=Sereno|first1=P. C.|date=2000|chapter=The fossil record, systematics and evolution of pachycephalosaurs and ceratopsians from Asia|chapter-url=https://d3qi0qp55mx5f5.cloudfront.net/paulsereno/i/docs/00-Marginocephalia.pdf|editor-last1=Benton|editor-first1=M. J.|editor-last2=Shishkin|editor-first2=M. A.|editor-last3=Unwin|editor-first3=D. M.|editor-last4=Kurochkin|editor-first4=E. N.|title=The Age of Dinosaurs in Russia and Mongolia|publisher=Cambridge University Press|page=489−492}}</ref><ref>{{cite book|last1=Makovicky|first1=P. J.|year=2001|chapter=A Montanoceratops cerorhynchus (Dinosauria: Ceratopsia) Braincase from the Horseshoe Canyon Formation of Alberta|chapter-url=https://archive.org/details/mesozoicvertebra0000unse/page/242/mode/2up?q=montanoceratops|editor-last1=Tanke|editor-first1=D. H.|editor-last2=Carpenter|editor-first2=K.|title=Mesozoic Vertebrate Life|series=Life of the Past|publisher=Indiana University Press|pages=243–262|isbn=978-0-253-33907-2}}</ref> [[Łukasz Czepiński]] in 2019 concluded that the former has enough anatomical differences to be considered as a separate [[taxon]].<ref name=Czepiński19>{{cite journal|last1=Czepiński|first1=Ł.|date=2019|title=Ontogeny and variation of a protoceratopsid dinosaur Bagaceratops rozhdestvenskyi from the Late Cretaceous of the Gobi Desert|journal=Historical Biology|volume=32|issue=10|pages=1394–1421|doi=10.1080/08912963.2019.1593404|bibcode=2020HBio...32.1394C |s2cid=132780322|url=http://dinosaurmailinglist.cmnh.org/2019Apr/pdfzmfpMk1aO4.pdf|access-date=10 June 2022|archive-date=8 July 2021|archive-url=https://web.archive.org/web/20210708144840/http://dinosaurmailinglist.cmnh.org/2019Apr/pdfzmfpMk1aO4.pdf|url-status=dead}}</ref>

In 2001 [[Oliver Lambert (paleontologist)|Oliver Lambert]] with colleagues named a new and distinct species of ''Protoceratops'', ''P. hellenikorhinus''. The first known remains of ''P. hellenikorhinus'' were collected from the Bayan Mandahu locality of the [[Bayan Mandahu Formation]], Inner Mongolia, in 1995 and 1996 during [[China|Sino]]-Belgian paleontological expeditions. The holotype (IMM 95BM1/1) and [[paratype]] (IMM 96BM1/4) specimens consist of large skulls lacking body remains. The holotype skull was found facing upwards, a pose that has been reported in ''Protoceratops'' specimens from Tugriken Shireh. The specific name, ''hellenikorhinus'', is derived from [[Greek language|Greek]] hellenikos (meaning Greek) and rhis (meaning nose) in reference to its broad and angular snout, which is reminiscent of the straight profiles of [[Ancient Greek sculpture|Greek sculptures]].<ref name=Helleniko2001>{{cite journal|last1=Lambert|first1=O.|last2=Godefroit|first2=P.|last3=Li|first3=H.|last4=Shang|first4=C.-Y.|last5=Dong|first5=Z.|date=2001|title=A new Species of Protoceratops (Dinosauria, Neoceratopsia) from the Late Cretaceous of Inner Mongolia (P. R. China)|journal=Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre|volume=71|pages=5–28|url=http://biblio.naturalsciences.be/rbins-publications/bulletin-of-the-royal-belgian-institute-of-natural-sciences-earth-sciences/71-sup-2001/irscnb_p4087_01ec08x_71-sup_bulletin-1.pdf}}</ref> In 2017 abundant protoceratopsid material was reported from [[Alxa League|Alxa]] near Bayan Mandahu,<ref>{{cite journal|last1=Ji|first1=S.|last2=Zhang|first2=L.|last3=Lu|first3=L.|last4=Hao|first14=J.|date=2017|title=The First Discovery of the Late Cretaceous Protoceratopsid Fauna from Alxa, Inner Mongolia, China|journal=Acta Geologica Sinica (English Edition)|volume=91|issue=5|pages=1908–1909|doi=10.1111/1755-6724.13421|bibcode=2017AcGlS..91.1908J |s2cid=134276217 |url=http://www.geojournals.cn/dzxbcn/ch/reader/create_pdf.aspx?file_no=2017endzxb05027&year_id=2017&quarter_id=5&falg=1|url-access=subscription}}</ref> and it may be preferable to ''P. hellenikorhinus''.<ref name=Czepiński19/>

[[Viktor Tereshchenko]] and [[Vladimir R. Alifanov]] in 2003 named a new protoceratopsid dinosaur from the Bayn Dzak locality, ''Bainoceratops efremovi ''. This genus was based on a few dorsal (back) vertebrae that were stated to differ from those of ''Protoceratops''.<ref>{{cite journal|last1=Tereshchenko|first1=V.|last2=Alifanov|first2=V. R.|date=2003|title=Bainoceratops efremovi, a New Protoceratopid Dinosaur (Protoceratopidae, Neoceratopsia) from the Bain-Dzak Locality (South Mongolia)|journal=Paleontological Journal|volume=37|issue=3|pages=293–302|url=https://www.researchgate.net/publication/288557787}}</ref> In 2006 North American paleontologists [[Peter Makovicky]] and [[Mark A. Norell]] suggested that ''Bainoceratops'' may be synonymous with ''Protoceratops'' as most of the traits used to separate the former from the latter have been reported from other ceratopsians including ''Protoceratops'' itself, and they are more likely to fall within the wide intraspecific variation range of the concurring ''P. andrewsi''.<ref name=Makovicky2006>{{cite journal|last1=Makovicky|first1=P. J.|last2=Norell|first2=M. A.|date=2006|title=Yamaceratops dorngobiensis, a New Primitive Ceratopsian (Dinosauria: Ornithischia) from the Cretaceous of Mongolia|journal=American Museum Novitates|number=3530|pages=1–42|doi=10.1206/0003-0082(2006)3530[1:YDANPC]2.0.CO;2|hdl=2246/5808|hdl-access=free|url=https://digitallibrary.amnh.org/bitstream/handle/2246/5808//v2/dspace/ingest/pdfSource/nov/N3530.pdf?sequence=1&isAllowed=y}}</ref> The authors [[Brenda J. Chinnery]] and [[Jhon R. Horner]] in 2007 during their description of ''[[Cerasinops]]'' stated that ''Bainoceratops'', along with other dubious genera, was determined to be either a variant or immature specimen of other genera. Based on this reasoning, they excluded ''Bainoceratops'' from their phylogenetic analysis.<ref>{{cite journal|last1=Chinnery|first1=B. J.|last2=Horner|first2=J. R.|date=2007|title=A new neoceratopsian dinosaur linking North American and Asian taxa|journal=Journal of Vertebrate Paleontology|volume=27|issue=3|pages=625–641|doi=10.1671/0272-4634(2007)27[625:ANNDLN]2.0.CO;2|s2cid=86091277 |url=https://www.academia.edu/24240715}}</ref>