''Weygoldtina'' is an extinct genus of

tailless whip scorpion Amblypygi is an ancient order of arachnid chelicerate arthropods also known as African cave-dwelling spiders, whip spiders and tailless whip scorpions (not to be confused with whip scorpions or vinegaroons that belong to the related order Thelyph ...

known from

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

fossil record, and the only known member of the family Weygoldtinidae. The genus is known from two species described from

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

and

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

and originally described in the genus ''Graeophonus'', which has to be treated as a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

''.

History

A monograph of the terrestrial Palaeozoic Arachnida of North America photos 23-29 27

A single fossil from the

Cape Breton Island Cape Breton Island (french: link=no, île du Cap-Breton, formerly '; gd, Ceap Breatainn or '; mic, Unamaꞌki) is an island on the Atlantic coast of North America and part of the province of Nova Scotia, Canada. The island accounts for 18. ...

was interpreted as a fossil dragonfly larva and described by

Samuel Hubbard Scudder Samuel Hubbard Scudder (April 13, 1837 – May 17, 1911) was an American entomologist and paleontologist. He was a leading figure in entomology during his lifetime and the founder of insect paleontology in America. In addition to fossil insects, ...

in 1876 as ''Libellula carbonaria''. The fossil was very incomplete, consisting of a solitary

opisthosoma The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma (cephalothorax). It is a distinctive feature of the subphylum Chelicerata (arachnids, horseshoe crabs and others). Although it is similar in most respects to a ...

. With the discovery of more complete fossils from Mazon Creek, Illinois, and

Joggins, Nova Scotia Joggins is a rural community located in western Cumberland County, Nova Scotia, Canada. On July 7, 2008 a 15-km length of the coast constituting the Joggins Fossil Cliffs was officially inscribed on the World Heritage List.amblypygids and moved the species to a new genus, ''Graeophonus'' as ''Graeophonus carbonarius''. While describing the British species, ''Graeophonus anglicus'',

Reginald Innes Pocock Reginald Innes Pocock F.R.S. (4 March 1863 – 9 August 1947) was a British zoologist. Pocock was born in Clifton, Bristol, the fourth son of Rev. Nicholas Pocock and Edith Prichard. He began showing interest in natural history at St. Edward ...

noted significant differences between the Nova Scotian and more complete Mazon Creek fossils. 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. ''Graeophonus anglicus'' has been found in the English Middle Coal Measures of Coseley,

Staffordshire Staffordshire (; postal abbreviation Staffs.) is a landlocked county in the West Midlands region of England. It borders Cheshire to the northwest, Derbyshire and Leicestershire to the east, Warwickshire to the southeast, the West Midlands Cou ...

. Known from ten specimens that are now deposited in the

British Museum The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It docum ...

, the species was named by Reginald Pocock in 1911. 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. Even in 1911, Pocock considered that the holotype specimen possibly did not belong to an amplypygid. 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 ''Weygoldtina scudderi'', and ''G. anglicus'' is renamed as ''Weygoldtina anglica''.

Morphology

''W. scudderi'' had body length about . Body length of ''W. anglica'' ranges from for complete specimens, and the partly complete long specimen shows a distinct pear-shaped ocular tubercle on the

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

. CT data confirmed the presence of lateral eye tubercles. The center of the dorsal shield has a deep depression which probably acted as an attachment site for the muscles of the sucking stomach. Raptorial pedipalps were not mantis-like shaped like most of modern amplypygid but similar to ones of modern genus ''

Paracharon ''Paracharon'' is a genus of tailless whip scorpion. A single species, ''Paracharon caecus'' has been described. It is endemic to Guinea-Bissau. An undescribed species is known from Colombia. It is the most basal known living member of Amblypygi, ...

''. Main difference of pedipalp compared to ''Paracharon'' is the spine orientation. While the pedipalp spines in ''Paracharon'' appear to be almost parallel and slightly tilted outwards, ''W. anglica'', however, 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''. Study in 2021 shows two prominent spines on each pedipalp, which were not recognized before. Although first pairs of legs are not completely preserved, they are probably long and antenna-like, same as modern amblypygids. Main difference of two species is anterior projection from the prosomal dorsal shield. It is slightly wider, shorter and more diffuse in ''W. scudderi''.

Classification

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 Paracharontidae is an arachnid family within the order of tailless whip scorpions. Paracharontidae and Weygoldtinidae form the suborder Paleoamblypygi, the putative sister group to the remaining Amblypygi; this suborder is primarily known from L ...

, 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 the blindness was not considered a reason to exclude ''Graeophonus'' from Paracharontidae. However, in 2017, ''Weygoldtina'' is rejected from Paracharontidae, and treated as stem- paleoamblypygid. Paleoamblypygi is a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

suborder that contains ''Paracharon'', ''Weygoldtina'', in addition ''Paracharonopsis cambayensis'' that is described from Eocene

Cambay Cambay, Kambay or Khambhat was a princely state in India during the British Raj. The City of Khambat (Cambay) in present-day Gujarat was its capital. The state was bounded in the north by the Kaira district and in the south by the Gulf of Cam ...

amber Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In Ma ...

. In 2018, new family Weygoldtinidae is given for ''Weygoldtina''. Differences in morphology of pedipalps and first pair of leg 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 own specialisations.

History

Morphology

Classification

References

Further reading