Trigonotarbid Arachnid Research Articles

GIGANTOCHARINUS SZATMARYI,A NEW TRIGONOTARBID ARACHNID FROM THE LATE DEVONIAN OF NORTH AMERICA (CHELICERATA, ARACHNIDA, TRIGONOTARBIDA)

A new trigonotarbid arachnid, Gigantocharinus szatmaryi new genus and species, is described from Upper Devonian (Late Famennian) sediments in Pennsylvania. Devonian trigonotarbids were known before from only a single North American locality and several European ones. The new trigonotarbid occurs in what had previously been a significant time gap between the faunas of the Middle Devonian and the late Carboniferous. Gigantocharinus szatmaryi is assigned with some hesitation to the family Palaeocharinidae.

A replacement name for the trigonotarbid arachnid Eotarbus Dunlop

The trigonotarbid arachnid genus Eotarbus was proposed by Dunlop (1996) as a plesion taxon for a new species from the upper Silurian of Ludford Lane, Shropshire. It has since been brought to my attention that the name is preoccupied. Eotarbus Kušta, 1888 was proposed for a single species of Carboniferous arachnid, Eotarbus litoralis Kušta, 1888 from Rakovnik in the Czech Republic. This preoccupation is unfortunate, as Kušta’s paper gives only a figure for this species and no formal description. Petrunkevitch (1953) reported the holotype and only known specimen as having been lost 50 years prior to his monograph, and as such was unable to place the genus, assigning it to Architarbi incertae sedis. Whilst there is clearly a case for suppressing the original use of the name Eotarbus due to the lost and inadequately described type material, a replacement generic name is proposed herein for the Ludford Lane trigonotarbid.

A redescription of the trigonotarbid arachnidPocononia whitei (Ewing 1930)

The trigonotarbid arachnid,Pocononia whitei (Ewing 1930), is redescribed and referred to the family Eophrynidae as the oldest known eophrynid. It suggests that trigonotarbids had diversified into the recognised Upper Carboniferous families by the Lower Carboniferous.

The palaeobiology of the Writhlington trigonotarbid arachnid

The morphology of the trigonotarbid arachnid from the Upper Carboniferous (Westphalian D) Writhlington Geological Nature Reserve is reconstructed, its opisthosomal segmentation determined, and its mode of life and palaeoecology discussed. Comparison of this material with other trigonotarbids in the family Eophrynidae from the Westphalian D of Mazon Creek and the Graigola Coal Seam, South Wales, suggests that all these forms can be referred to Pleophrynus verrucosa ( Pocock, 1911 ), which appears to have had two morphotypes, perhaps representing sexual dimorphism. P. verrucosa was widely distributed within the Westphalian D Coal Measures and supports the hypothesis of a single terrestrial faunal province in the European and North American Westphalian D.

Land Animals in the Silurian: Arachnids and Myriapods from Shropshire, England

A new assemblage of arthropod cuticles from Upper Silurian rocks in Shropshire, England, includes at least two centipedes and a trigonotarbid arachnid. This unequivocal terrestrial fauna from the Silurian constitutes the earliest direct record of land animals. The presence of predatory arthropods suggests that complex terrestrial ecosystems were in place by the late Silurian (414 x 10(6) years before present) and that the animal invasion of the land occurred earlier than was previously thought.