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{{Short description|Genus of rhamphorhynchine pterosaur}}
{{Use dmy dates|date=April 2022}}
{{Speciesbox
| name = ''Dearc''
| fossil_range = [[Middle Jurassic]], {{fossil range|Bathonian|Bathonian|[[Bathonian]]}}
| image = Dearc restoration.jpg
| image_caption = [[Paleoart|Life restoration]]
| display_parents = 3
| genus = Dearc
| parent_authority = Jagielska ''et al.'', [[2022 in paleontology|2022]]
| species = sgiathanach
| authority = Jagielska ''et al.'', 2022
}}

'''''Dearc''''' ({{IPA-gd|tʲɛrxk}} {{Audio|Dearc.ogg|dearc}}) is a genus of large-bodied [[rhamphorhynchine]] pterosaur from the Middle Jurassic [[Lealt Shale Formation]] of [[Scotland]]. The holotype, a juvenile or subadult that was still actively growing, has an estimated wingspan of 2.5 to 3 meters, making it the largest flying animal of its time. This pushes the origin of large pterosaurs back significantly, as it was previously assumed that pterosaurs did not reach greater body sizes until the short-tailed [[pterodactyloid]] lineages of the [[Cretaceous]]. The genus contains a single species, '''''Dearc sgiathanach''''' ({{IPA-gd|ˈtʲɛɾxk ˈs̪kʲiəhanəx|}} {{Audio|Dearc sgiathanach.ogg|dearc sgiathanach}}).

==Discovery and naming==
The [[holotype]] of ''Dearc'', [[National Museums Scotland|NMS]] G.2021.6.1-4, was found in 2017 by Amelia Penny in the [[Lealt Shale Formation]] and consists of a three-dimensionally preserved skeleton preserved in articulation in a slab of [[limestone]] (separated into four pieces for preparation). The specimen preserves most of the body with the exception of the end of the tail, most of the hindlimbs, parts of the wing and the very tip of the beak. The specimen was found on the east coast of the peninsula of [[Trotternish]], part of the [[Isle of Skye]] in north-west [[Scotland]], and the rock slab removed to the [[University of Edinburgh]].<ref name="BBC--60407928">{{cite web |title=Fossil of largest Jurassic pterosaur found on Skye |url=https://www.bbc.co.uk/news/science-environment-60407928 |website=BBC News |access-date=22 February 2022 |date=22 February 2022}}</ref> The fossil was prepared by Nigel Larkin. It is to be displayed by [[National Museums Scotland]].<ref name="BBC--60407928" /><ref name="Ferguson2022">{{cite web |last1=Ferguson |first1=Brian |title=World's biggest Jurassic-era pterodactyl discovered on Isle of Skye |url=https://www.scotsman.com/whats-on/arts-and-entertainment/worlds-biggest-jurassic-era-pterodactyl-discovered-on-isle-of-skye-3580073 |website=The Scotsman |access-date=22 February 2022 |date=22 February 2022}}</ref>

In 2022, the [[type species]] ''Dearc sgiathanach'' was named and described by Natalia Jagielska, Michael O’Sullivan, Gregory F. Funston, Ian B. Butler, Thomas J. Challands, Neil D.L. Clark, Nicholas C. Fraser, Amelia Penny, Dugald A. Ross, Mark Wilkinson and [[Stephen L. Brusatte|Stephen Louis Brusatte]]. The name is derived from the [[Scottish Gaelic]] language and has a double meaning. It can be simultaneously translated as "winged reptile" and "reptile from Skye", as ''dearc'' means "reptile" and ''sgiathanach'' (from ''sgiathan'' "small wing") means "winged", an element that also appears in the Gaelic name of the [[Isle of Skye]] ({{lang|gd|An t-Eilean Sgiathanach}}), often interpreted as meaning "The Winged Island".<ref name=Jagielska>{{Cite Q|Q110984418}}</ref>

==Description==
===Size===
[[File:Dearc wingspan.png|thumb|Different wingspan estimates for ''Dearc'' (based on ''[[Rhamphorhynchus]]'' and ''[[Dorygnathus]]'')|right]]
The wingspan could not be directly measured for ''Dearc'' as several [[phalanges]] of the wingfinger were missing, in particular the very tip and a central portion of the wing. However, an estimate could be made based on comparison with better sampled taxa, in this case ''Rhamphorhynchus'' and ''[[Dorygnathus]]''. Using the proportions of ''Rhamphorhynchus'', an estimated wingspan between 2.2 meters (based on skull length) and 3.8 meters (based on humerus length) was recovered. Estimates based on the humerus length of ''Dorygnathus'' give an estimated wingspan of 1.9 meters. These results already make ''Dearc'' one of the largest known Jurassic pterosaurs, larger than the largest ''Dorygnathus'' (1.69 meters wingspan) and smaller among non-pterodactyloids only than a large rhamphorhynchid specimen from Ettling in [[Germany]], consisting of two possible neck vertebrae, which may belong to the genus ''Rhamphorhynchus''.<ref name=Jagielska/><ref>{{cite journal |last1=Spindler |first1=Frederik |last2=Ifrim |first2=Christina |title=Die Spur einer Spur – ein möglicher erster Flugsaurier aus Ettling Trace of a trace – a putative first pterosaur from the Ettling locality |journal=Archaeopteryx|volume=37|pages= 75–83|date=2021 |url=https://www.researchgate.net/publication/357673254}}</ref> The larger interpretation is favored by the authors for a series of reasons including the well established [[ontogeny|ontogenetic series]] of ''Rhamphorhynchus'', [[Phylogeny|phylogenetic proximity]].<ref name=Jagielska/>

''Dearc'' possesses several features typical of fully grown adults in the related ''[[Rhamphorhynchus]]'', including the large recurved teeth of the [[premaxilla]], the well developed crest of the [[humerus]], fusion between the [[scapula]]-[[coracoid]], smooth bone texture and other features. However, at the same time other areas of the fossil show signs of immaturity, including unfused bones of the skull and unfused [[sacral vertebrae]]. [[Histology]] supports the later interpretation, indicating that, while at least two years old at its time of death, the animal was still actively growing. The wing bone shows two prominent lines of growth that allow this interpretation and further suggest that it died shortly after emerging from a hiatus in growth. The fact that the holotype of ''Dearc'' was still growing makes a wingspan of up to three meters quite possible.<ref name=Jagielska/>

===Skeletal anatomy===
Generally, ''Dearc'' shows the typical bodyplan of non-[[monofenestrata]]n pterosaurs. The neck was short and the tail elongated, supported by interlocking [[zygapophyses]] of the caudal vertebrae. The mandibular symphysis is elongated and the [[metacarpus]] short. There are however some features shared with [[pterodactyloids]] such as a skull longer than the dorsal and sacral vertebrae combined and the shape of the [[quadrate (bone)|quadrate]]. Furthermore, although proportionally short compared to pterodactyloids, the [[cervical vertebrae]] are notably elongated compared to other non-monofenestratans, resembling those of the more derived ''[[Wukongopterus]]''. The dentition shows two distinct types of teeth: elongated fangs close to the tip of the snout and more conical peg-like teeth further back.<ref name=Jagielska/>

The describing authors indicated several distinguishing traits. Four are [[autapomorphies]], unique derived characters. In the palate, the vomers contain three tubes, forming a trident. The contribution of the upper jaw bone, the maxilla, to the palate, in front of the [[choana]], the inner nostril, has a depression. The brain has enlarged optic lobes that are expanded lengthwise. In the foot the fourth metatarsal is more robust than the first, second and third metatarsal, about 2.5 times as thick. Additionally, there are two traits that in themselves are not unique but the combination of which is unique. The [[infratemporal fenestra]] is pear-shaped, with the narrow part on top. In the palate, the [[ectopterygoid bone]] has an upwards projecting process, running through the choana and perpendicularly contacting the vomer.<ref name=Jagielska/>

==Phylogeny==
The phylogenetic analysis conducted for ''Dearc'' included characters from several independent publications as well as entirely new ones, while also excluding those that are only known from very young animals or known to vary greatly with age. The resulting tree recovered ''Dearc'' to lie within the [[Rhamphorhynchidae]], specifically in a clade alongside ''[[Angustinaripterus]]'' and ''[[Sericipterus]]'', the [[Angustinaripterini]].<ref name=Jagielska/>
{{clade| style=font-size:85%;line-height:85%
  |1={{clade
   |1=[[Lagerpetidae]]
   |2={{clade
    |1=''[[Raeticodactylus|Raeticodactylus filisurensis]]''
    |2={{clade 
     |1=''[[Preondactylus|Preondactylus bufarinii]]''
     |2=''[[Eudimorphodon|Eudimorphodon ranzii]]''
     |3={{clade 
      |1={{clade
       |1=''[[Dimorphodon|Dimorphodon macronyx]]''
       |2=''[[Caelestiventus|Caelestiventus hanseni]]''
}}
      |2={{clade
       |1=''[[Campylognathoides|Campylognathoides zitteli]]''
       |2={{clade
        |1={{clade
         |1=''[[Fenghuangopterus|Fenghuangopterus lii]]''
         |2=''[[Jianchangnathus|Jianchangnathus robustus]]''
         |3=''[[Scaphognathus|Scaphognathus crassirostris]]''
         |4=''[[Dorygnathus|Dorygnathus banthensis]]''
}}
        |2={{clade
         |1=''[[Cacibupteryx|Cacibupteryx caribensis]]''
         |2=''[[Parapsicephalus|Parapsicephalus purdoni]]''
}}
        |3={{clade
         |1=''[[Rhamphorhynchus|Rhamphorhynchus muensteri]]''
         |label2=[[Angustinaripterini]]
         |2={{clade
          |1=''[[Angustinaripterus|Angustinaripterus longicephalus]]''
          |2='''''Dearc sgiathanach'''''
          |3=''[[Sericipterus|Sericipterus wucaiwanensis]]''
}}}}
        |4={{clade
         |1=''[[Changchengopterus|Changchengopterus pani]]''
         |2=[[Wukongopteridae]]
         |3=[[Anurognathidae]]
         |4=[[Pterodactyloidea]]
}}}}}}}}}}}}}}}}

==References==
{{Reflist}}

{{Portal bar|Paleontology|Scotland}}
{{Pterosauria|B.}}
{{Taxonbar|from1=Q110983876|from2=Q110986200}}

[[Category:Jurassic pterosaurs of Europe]]
[[Category:Rhamphorhynchids]]
[[Category:Fossil taxa described in 2022]]
[[Category:Isle of Skye]]
[[Category:Fossils of Scotland]]
[[Category:Jurassic Scotland]]
[[Category:Bathonian genera]]
[[Category:Middle Jurassic reptiles of Europe]]