Weygoldtina is an extinct genus of Amblypygi known from Carboniferous period, and the only known member of the family Weygoldtinidae.
History
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.
The fossil was very incomplete, consisting of a solitary
opisthosoma.
With the discovery of more complete fossils from Mazon Creek, Illinois, and Joggins, Nova Scotia, Samuel Scudder redescribed the fossils as
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.
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.
has been found in the English
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.
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.
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 Tubercle on the carapace.
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
in
Weygoldtina is very similar to the modern genus
Paracharon. In 2007,
Weygoldtina (
Graeophonus at that time) was placed in
Paracharontidae, 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-
Paleoamblypygi. Paleoamblypygi is a
Monophyly suborder that contains
Paracharon,
Weygoldtina, in addition
Paracharonopsis that is described from Eocene
Cambay State amber.
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.
Further reading
-
Dunlop, J.A. (1994). An Upper Carboniferous amblypygid from the Writhlington Geological Nature Reserve. Proceedings of the Geologists' Association 105:245-250.
