A new species of trigonotarbid arachnid from the Pilsen Basin of the Czech Republic

New records of the extinct arachnid order Trigonotarbida are described from Upper Pennsylvanian (Moscovian: Bolsovian [ = Westphalian C]) spoil heaps associated with the Týnec mine near the village of Týnec in West Bohemia, Czech Republic. Three specimens are recorded, two of which are incomplete opisthosomas assigned to Trigonotarbida incertae sedis. A third fossil is more complete and is described here as Tynecotarbus tichaveki gen. et sp. nov. Its familial position is uncertain, but the presence of a weakly lobed carapace and finely tuberculate body ornament suggests affinities with the ‘eophrynid assemblage’ sensu Dunlop & Brauckmann (2006) and particularly the family Lissomartidae from Mazon Creek, USA. In order to be comprehensive in our study, we include a complete list of Czech trigonotarbids.

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.