Leogorgon

{{Short description|Extinct genus of dubious therapsids}}

{{Short description|Extinct genus of dubious therapsids}}

{{Speciesbox

{{Speciesbox

| fossil_range = [[Late Permian]], ([[Wuchiapingian]]), {{Fossil range|258|254}}

| fossil_range = [[Late Permian]], ([[Wuchiapingian]]), {{Fossil range|255|254}}

| image = Inostrancevia alexandri teeth.JPG

| image = Inostrancevia alexandri teeth.JPG

| image_caption = The referred [[incisor]] of ''Leogorgon'' (PIN 4549/14; bottom), compared with a [[canine tooth]] of ''[[Inostrancevia]]'' (top), both exhibited in Dinosaurium, Prague

| image_caption = The referred [[incisor]] of ''Leogorgon'' (PIN 4549/14; bottom), compared with a [[canine tooth]] of ''[[Inostrancevia]]'' (top), both exhibited in Dinosaurium, Prague

==History==

==History==

In 2003, the Russian paleontologist [[Mikhail F. Ivakhnenko]] described a new [[genus]] and [[species]] of [[therapsid]], which he identified as a [[gorgonopsia]]n, ''Leogorgon klimovensis''. This description is based on a partial [[braincase]] designated as the [[holotype]], as well as an isolated [[incisor]], both discovered at the Klimovo-1 locality (from which the [[Specific name (zoology)|specific name]] is derived), in Russia's [[Vologda Oblast]]. In Russian [[stratigraphy]], the site is dated to the early Vyatkian, a time interval that largely corresponds to the [[Wuchiapingian]] [[Stage (stratigraphy)|stage]] of the [[Late Permian]] according to the [[International Commission on Stratigraphy]]. These two fossil specimens, initially reported by Ivakhnenko in a work published two years earlier, are housed at the [[Paleontological Institute of the Russian Academy of Sciences]] in [[Moscow]] under their respective catalogue numbers PIN 4549/13 and PIN 4549/14.{{cite book|language=ru|last=Ivakhnenko|first=Mikhail F.|title=Тетраподы Восточно-Европейского плакката - позднепалеозойского территориально-природного комплекса|trans-title=Tetrapods of the East European Plakkat - Late Paleozoic Territorial-Natural Complex|publisher=Trudy Paleontologiceskogo Instituta|location=[[Perm, Russia|Perm]]|volume=283|pages=100|year=2001|isbn=5-88345-064-4|url={{google books|plainurl=yes|id=N524Vah8MRAC|page=100}}}}{{cite journal|last=Ivakhnenko|first=Mikhail F.|year=2003|title=Eotherapsids from the East European placket (Late Permian)|journal=[[Paleontological Journal]]|volume=37|issue=S4|pages=339–465|issn=0031-0301}} The [[Binomial nomenclature|generic name]] ''Leogorgon'' honors the Russian paleontologist [[Leonid P. Tatarinov]], who had previously named the small gorgonopsian ''[[Viatkogorgon ivakhnenkoi]]'' in 1999 in honor of Ivakhnenko.{{cite journal|last1=Tatarinov|first1=Leonid P.|title=New theriodonts (Reptilia) from the Late Permian fauna of the Kotelnich locality, Kirov Region|journal=[[Paleontological Journal]]|year=1999|volume=33|issue=5|pages=550–554}} The name "[[gorgon]]", referring to the monstrous [[hag]]s of [[Greek mythology]], is often used in the generic names of gorgonopsians.{{cite journal|last1=Kammerer|first1=Christian F.|last2=Masyutin|first2=Vladimir|title=Gorgonopsian therapsids (''Nochnitsa'' gen. nov. and ''Viatkogorgon'') from the Permian Kotelnich locality of Russia|journal=[[PeerJ]]|year=2018|volume=6|article-number=e4954|pmid=29900078|doi=10.7717/peerj.4954|pmc=5995105|doi-access=free}}

In 2003, the Russian paleontologist [[Mikhail F. Ivakhnenko]] described a new [[genus]] and [[species]] of [[therapsid]], which he identified as a [[gorgonopsia]]n, ''Leogorgon klimovensis''. This description is based on a partial [[braincase]] designated as the [[holotype]], as well as an isolated [[incisor]], both discovered at the Klimovo-1 locality (from which the [[Specific name (zoology)|specific name]] is derived), in Russia's [[Vologda Oblast]]. In Russian [[stratigraphy]], the site is dated to the Lower Vyatkian, a time interval that largely corresponds to the end of the [[Wuchiapingian]] [[Stage (stratigraphy)|stage]] of the [[Late Permian]] according to the [[International Commission on Stratigraphy]].{{cite journal|last1=Davydov|first1=Vladimir I.|last2=Arefiev|first2=Mikhail P.|last3=Golubev|first3=Valeriy K.|last4=Karasev|first4=Eugeny V.|last5=Naumcheva|first5=Maria A.|last6=Schmitz|first6=Mark D.|last7=Silantiev|first7=Vladimir V.|last8=Zharinova|first8=Veronika V.|year=2020|title=Radioisotopic and biostratigraphic constraints on the classical Middle–Upper Permian succession and tetrapod fauna of the Moscow syneclise, Russia|journal=[[Geology (journal)|Geology]]|volume=48|issue=7|pages=742–747|doi=10.1130/G47172.1|s2cid=219035821|url=https://www.researchgate.net/publication/341037505}} These two fossil specimens, initially reported by Ivakhnenko in a work published two years earlier, are housed at the [[Paleontological Institute of the Russian Academy of Sciences]] in [[Moscow]] under their respective catalogue numbers PIN 4549/13 and PIN 4549/14.{{cite book|language=ru|last=Ivakhnenko|first=Mikhail F.|title=Тетраподы Восточно-Европейского плакката - позднепалеозойского территориально-природного комплекса|trans-title=Tetrapods of the East European Plakkat - Late Paleozoic Territorial-Natural Complex|publisher=Trudy Paleontologiceskogo Instituta|location=[[Perm, Russia|Perm]]|volume=283|pages=100|year=2001|isbn=5-88345-064-4|url={{google books|plainurl=yes|id=N524Vah8MRAC|page=100}}}}{{cite journal|last=Ivakhnenko|first=Mikhail F.|year=2003|title=Eotherapsids from the East European placket (Late Permian)|journal=[[Paleontological Journal]]|volume=37|issue=S4|pages=339–465|issn=0031-0301}} The [[Binomial nomenclature|generic name]] ''Leogorgon'' honors the Russian paleontologist [[Leonid P. Tatarinov]], who had previously named the small gorgonopsian ''[[Viatkogorgon ivakhnenkoi]]'' in 1999 in honor of Ivakhnenko.{{cite journal|last1=Tatarinov|first1=Leonid P.|title=New theriodonts (Reptilia) from the Late Permian fauna of the Kotelnich locality, Kirov Region|journal=[[Paleontological Journal]]|year=1999|volume=33|issue=5|pages=550–554}} The name "[[gorgon]]", referring to the monstrous [[hag]]s of [[Greek mythology]], is often used in the generic names of gorgonopsians.{{cite journal|last1=Kammerer|first1=Christian F.|last2=Masyutin|first2=Vladimir|title=Gorgonopsian therapsids (''Nochnitsa'' gen. nov. and ''Viatkogorgon'') from the Permian Kotelnich locality of Russia|journal=[[PeerJ]]|year=2018|volume=6|article-number=e4954|pmid=29900078|doi=10.7717/peerj.4954|pmc=5995105|doi-access=free}}

After limiting himself to a comparison with South African [[rubidgeine]]s in his 2001 work, Ivakhnenko identified ''Leogorgon'' in his 2003 paper as the first representative of this [[subfamily]] known from Russia. He based this assignment on the morphology of the holotype braincase, which exhibits a short and tall paroccipital [[Process (anatomy)|process]] (the lateral part of the [[occipital bone]]), considered comparable only to that of ''[[Dinogorgon]]'' among members of the group. As for the single incisor attributed to the [[taxon]], he described it as similar to those of ''[[Inostrancevia]]'', while suggesting it could be distinguished by a more weakly-faceted [[Crown (tooth)|crown]] and a more developed mesial cutting edge. Based on comparisons with genera he regarded as related, Ivakhnenko estimated the complete skull length at around {{cvt|70|cm}}, which would make ''Leogorgon'' the largest known gorgonopsian, exceeding the already considerable cranial dimensions of ''Inostrancevia'' and ''[[Rubidgea]]'', which exceed {{cvt|40|cm}}.

After limiting himself to a comparison with South African [[rubidgeine]]s in his 2001 work, Ivakhnenko identified ''Leogorgon'' in his 2003 paper as the first representative of this [[subfamily]] known from Russia. He based this assignment on the morphology of the holotype braincase, which exhibits a short and tall paroccipital [[Process (anatomy)|process]] (the lateral part of the [[occipital bone]]), considered comparable only to that of ''[[Dinogorgon]]'' among members of the group. As for the single incisor attributed to the [[taxon]], he described it as similar to those of ''[[Inostrancevia]]'', while suggesting it could be distinguished by a more weakly-faceted [[Crown (tooth)|crown]] and a more developed mesial cutting edge. Based on comparisons with genera he regarded as related, Ivakhnenko estimated the complete skull length at around {{cvt|70|cm}}, which would make ''Leogorgon'' the largest known gorgonopsian, exceeding the already considerable cranial dimensions of ''Inostrancevia'' and ''[[Rubidgea]]'', which exceed {{cvt|40|cm}}.