Weygoldtina

{{Short description|Extinct genus of whip scorpions}} {{distinguish|text=living tailless whip scorpion genus, Weygoldtia}} {{Automatic Taxobox | fossil_range = {{Fossil range|315|303.7|Pennsylvanian (Duckmantian–Kasimovian)}} | image = Weygoldtina anglica BMNH In 31248.png | image_caption = Fossil specimen of ''W. anglica'' | taxon = Weygoldtina | authority = Dunlop, 2018 | subdivision_ranks = Species | subdivision = *''Weygoldtina anglica'' Pocock, 1911 *''Weygoldtina scudderi'' Pocock, 1911 | synonyms = *''Graeophonus anglicus'' Pocock, 1911 *''Graeophonus scudderi'' Pocock, 1911 }}

'''''Weygoldtina''''' is an extinct genus of tailless whip scorpion known from Carboniferous period, and the only known member of the family '''Weygoldtinidae'''.<ref name=":0">{{Cite journal |last=Dunlop |first=Jason A. |date=2018-03-01 |title=Systematics of the Coal Measures whip spiders (Arachnida: Amblypygi) |url=https://www.sciencedirect.com/science/article/pii/S0044523117300967 |journal=Zoologischer Anzeiger |series=In honor of Peter Weygoldt |language=en |volume=273 |pages=14–22 |doi=10.1016/j.jcz.2017.11.004 |issn=0044-5231|url-access=subscription }}</ref> It is known from two species described from North America and England and originally described in the genus '''''Graeophonus''''',<ref name="GarwoodDunlop2017">{{cite journal |last1=Garwood |first1=Russell J. |last2=Dunlop |first2=Jason A. |last3=Knecht |first3=Brian J. |last4=Hegna |first4=Thomas A. |year=2017 |title=The phylogeny of fossil whip spiders |journal=BMC Evolutionary Biology |volume=17 |issue=1 |page=105 |doi=10.1186/s12862-017-0931-1 |issn=1471-2148 |pmid=28431496 |pmc=5399839 |doi-access=free}}</ref> which is now considered a ''nomen dubium''.<ref name=":0" />

==History== left|thumb|236x236px|''Weygoldtina scudderi'' (USNM 37969), originally described as ''Graeophonus carbonarius'' A single fossil from the Cape Breton Island was interpreted as a fossil dragonfly larva and described by Samuel Hubbard Scudder in 1876 as ''Libellula carbonaria''.<ref name="Scudder1876">{{cite journal |last1=Scudder |first1=S.H. |year=1876 |title=A century of Orthoptera. Decade VI. Forficulariae (North America) |journal=Proceedings of the Boston Society of Natural History |volume=18 |pages=257–264}}</ref><ref name="Dunlop2007">{{cite journal |last1=Dunlop |first1=J.A. |last2=Zhou |first2=G.R.S. |last3=Braddy |first3=S.J. |year=2007 |title=The affinities of the Carboniferous whip spider ''Graeophonus anglicus'' Pocock, 1911 (Arachnida:Amblypygi) |url=http://edoc.hu-berlin.de/18452/22508 |journal=Earth and Environmental Science Transactions of the Royal Society of Edinburgh |volume=98 |issue=2 |pages=165–178 |doi=10.1017/S1755691007006159|s2cid=140582794 }}</ref><ref name=":0" /> The fossil was very incomplete, consisting of a solitary opisthosoma.<ref name="Dunlop2007" /> With the discovery of more complete fossils from Mazon Creek, Illinois, and Joggins, Nova Scotia, Samuel Scudder redescribed the fossils as amblypygids and moved the species to a new genus, ''Graeophonus,'' as '''''Graeophonus carbonarius'''''. While describing the British species, ''Graeophonus anglicus'', Reginald Innes Pocock noted significant differences between the Nova Scotian and more complete Mazon Creek fossils.<ref name="Dunlop2007" /> As a result he erected the species '''''Graeophonus scudderi''''' to accommodate the Mazon Creek specimen, and restricted species ''G. carbonarius'' to the Canadian specimens. It was later suggested by Reginald Pocock in 1913 that the two species, ''G. carbonarius'' and ''G. scudderi'', were indeed the same, and this has resulted in confusion over both the name to be used and number of species present in North America.<ref name="Dunlop2007" /> '''''Graeophonus anglicus''''' has been found in the English Middle Coal Measures of Coseley, Staffordshire. Known from ten specimens that are now deposited in the British Museum, the species was named by Reginald Pocock in 1911.<ref name=":1">{{Cite book |last=Petrunkevitch |first=Alexander |url=https://books.google.com/books?id=U64LAQAAIAAJ |title=A Monograph of the Terrestrial Palaeozoic Arachnida of North America |date=1913 |publisher=Yale University Press |language=en}}</ref>

However, in 2018, researchers considered that the genus ''Graeophonus'' is invalid, because the holotype specimen of ''G. carbonarius'' (''Libellula carbonaria'') is poorly preserved and hard to identify as an amblypygid.<ref name=":0" /> Even in 1911, Pocock considered that the holotype specimen possibly did not belong to an amplypygid.<ref name=":1" /> More confusingly, A.I. Petrunkevitch suggested to use another more complete specimen as the holotype in 1913, even though the original holotype specimen was not lost at that time. To solve problems caused by this, Jason A. Dunlop erected a new genus, '''''Weygoldtina''''', and placed most specimens of ''G. carbonarius'' and ''G. scudderi'' into the '''''Weygoldtina scudderi''''', with ''G. anglicus'' being renamed as '''''Weygoldtina anglica'''''.<ref name=":0" />

== Morphology == {{Multiple image | direction = horizontal | image1 = Tomographic reconstruction of Weygoldtina anglica Graeophonus anglicus.png | image2 = Weygoldtina_anglica_Graeophonus_anglicus_reconstruction_longer_pedipalp_spines.png | align = left | caption1 = Tomographic (left) and illustrated (right) reconstruction of ''W. anglica'' }} ''W. scudderi'' had body length about {{convert|17|mm|in||}}.<ref name=":0" />

Body length of ''W. anglica'' ranges from {{convert|11|-|13|mm|in}} for complete specimens, and the partly complete {{convert|18|mm|in}} long specimen shows a distinct pear-shaped ocular tubercle on the carapace.<ref name="Dunlop2007" /> CT data confirmed the presence of lateral eye tubercles.<ref name="GarwoodDunlop2017" /> The center of the dorsal shield has a deep depression which probably acted as an attachment site for the muscles of the sucking stomach.<ref name="GarwoodDunlop2017" /> Raptorial pedipalps were not mantis-like shaped like most of modern amplypygid, but were similar to ones of the modern genus ''Paracharon''.<ref name="GarwoodDunlop2017" /> The main difference of pedipalps compared to ''Paracharon'' is the spine orientation. The pedipalp spines in ''Paracharon'' appear to be almost parallel and slightly tilted outwards; in ''W. anglica'', the angle between the spines appears to be larger, at least 90 degrees. This character suggests that ''W. anglica'' used its pedipalps not exactly in the same way as the modern ''Paracharon''.<ref name=":2">{{Cite journal |last1=Haug |first1=Carolin |last2=Haug |first2=Joachim T. |date=2021-09-01 |title=The fossil record of whip spiders: the past of Amblypygi |journal=PalZ |language=en |volume=95 |issue=3 |pages=387–412 |doi=10.1007/s12542-021-00552-z |s2cid=232434849 |issn=1867-6812|doi-access=free }}</ref> Study in 2021 shows two prominent spines on each pedipalp, which were not recognized before.<ref name=":2" /> Although the first pairs of legs are not completely preserved, they are probably long and antenna-like, the same as modern amblypygids.<ref name="GarwoodDunlop2017" />

The main difference between the two species is the anterior projection from the prosomal dorsal shield. It is slightly wider, shorter, and more diffuse in ''W. scudderi''.<ref name=":0" />

== Classification == [[File:A syntype of Paracharon caecus.png|thumb|Photos of the only living paleoamblypygid tailless whip scorpion, ''Paracharon caecus'']]

The morphology of both the abdomen and pedipalps in ''Weygoldtina'' is very similar to the modern genus ''Paracharon''. In 2007, ''Weygoldtina'' (''Graeophonus'' at that time) was placed in Paracharontidae, the same family as ''Paracharon''. While ''Paracharon'' is notably blind, this is thought to be a secondary result of living almost exclusively within termite mounds. Thus, its blindness was not considered a reason to exclude ''Graeophonus'' from Paracharontidae.<ref name="Dunlop2007" /> However, in 2017, ''Weygoldtina'' was rejected from Paracharontidae, and treated as stem-paleoamblypygid. Paleoamblypygi is a monophyletic suborder that contains ''Paracharon'', ''Weygoldtina'', in addition ''Paracharonopsis cambayensis'' that is described from Eocene Cambay amber.<ref name="GarwoodDunlop2017" /> In 2018, new family Weygoldtinidae is given for ''Weygoldtina''.<ref name=":0" /> Differences in morphology of the pedipalps and the first pair of legs in ''Paracharon'' and ''Weygoldtina'' may show closer relationship of ''Paracharon'' and Euamblypygi, but also this could be a point to an apomorphic condition of ''Weygoldtina''. Researchers claimed that it needs to be considered that ''Weygoldtina'' is not as similar to ''Paracharon'' as a brief look might suggest, but is characterised by its own specialisations.<ref name=":2" />

==References== {{Reflist}}

==Further reading== *[http://members.tripod.com/~DrJasonDunlop/pj3.html Dunlop, J.A.] (1994). An Upper Carboniferous amblypygid from the Writhlington Geological Nature Reserve. ''Proceedings of the Geologists' Association'' 105:245-250.

Category:Amblypygi Category:Carboniferous arachnids Category:Carboniferous arthropods of Europe Category:Carboniferous arthropods of North America Category:Fossil taxa described in 2018 Category:Paleozoic life of Nova Scotia