The youngest trigonotarbid <i>Permotarbus schuberti</i> n. gen., n. sp. from the Permian Petrified Forest of Chemnitz in Germany

Abstract

A new trigonotarbid (Arachnida: Trigonotarbida) is described as &lt;i&gt;Permotarbus schuberti&lt;/i&gt; n. gen., n. sp. from the Early Permian Petrified Forest (Rotliegend) of Chemnitz in Saxony (Germany). At ca. 290 Ma it represents the youngest record of this extinct arachnid order discovered to date. Its familial affinities are uncertain, but may lie close to the Aphantomartidae. The distribution of the trigonotarbid genera through time is summarised, together with a list of their seventy-seven fossil-yielding localities. Together they offer a broad overview of the group's fossil record, which is heavily biased towards the Moscovian Stage (ca. 307–312 Ma) of the Late Carboniferous in Europe and North America. This is due in no small part to numerous localities associated with coal mining districts, and trigonotarbids are found less frequently after this stage. While it is tempting to associate this with biological events – such as a putative "Carboniferous Rainforest Collapse" dating to ca. 305 Ma – it is difficult to differentiate the effects of genuine extinction patterns from artefacts caused by fewer appropriate localities in the economically less relevant latest Carboniferous and Early Permian strata. Nevertheless, trigonotarbids became extinct at some point after the Early Permian and loss of the Coal Measures forests remains one of the most likely possible causes. &lt;br&gt;&lt;br&gt; doi:&lt;a href="http://dx.doi.org/10.1002/mmng.201300012" target="_blank"&gt;10.1002/mmng.201300012&lt;/a&gt;

Newly Reported Trigonotarbid Specimens From Oklahoma and Indiana

“…• Ancient arachnid order found from the late Silurian to early Permian (ca. 419-290 Ma) (Dunlop 1996a, Dunlop & Rößler 2013.…”

Trigonotarbus johnsoni Pocock, 1911, revealed by X-ray computed tomography, with a cladistic analysis of the extinct trigonotarbid arachnids

“…420 Mya) through to the early Permian (Sakmarian; c . 290 Mya; Dunlop, ; Dunlop & Rößler, ). Sixty‐seven species are currently recognized in the literature, although this is probably an overestimate (see comments in Garwood & Dunlop, ).…”

“…The group appears to have peaked in abundance and diversity during the late Carboniferous ( c. 359–299 Mya) with the majority of fossils deriving from the Coal Measures of Europe and North America (Dunlop & Rößler, ). Indeed trigonotarbids can be amongst the most abundant arachnids in these strata (Garwood & Dunlop, ), with classic Westphalian (315–304 Mya; Moscovian to Kasimovian) localities, such as the British Middle Coal Measures and the Saarland of Germany being of particular importance.…”

A trigonotarbid arachnid from the Pennsylvanian Astrasado Formation of the Kinney Brick Quarry, New Mexico

“…Trigonotarbids are an extinct order of spider-like arachnids which have been recorded from the late Silurian through to the early Permian . For a recent overview of their geographical and stratigraphical distribution see Dunlop & Rößler (2013). Trigonotarbid fossils can be recognized by having a dorsal opisthosoma in which the tergites are divided longitudinally into median and lateral plates.…”

“…There is, however, something of a bias towards European localities, particularly regions historically associated with coal mining such as the British Midlands, northern France/southern Belgium, the German Saarland, Bohemia in the Czech Republic, and Silesia in Poland. Of the 77 trigonotarbid-yielding localities recorded by Dunlop and Rößler (2013) sixty-six are European (including Russia), ten are North American and one is from South America (Argentina). Note that four sites from the Lower Devonian of Germany can be added to this list (M. Poschmann, pers.…”