A revision of the Late Ordovician marrellomorph arthropod <i>Furca bohemica</i> from Czech Republic (project)

Abstract

The enigmatic marrellomorph arthropod Furca bohemica from the Upper Ordovician Letná Formation, is redescribed. Based on existing museum specimens and new material collected from the southern slope of Ostrý Hill (Beroun, Czech Republic), the morphology and taphonomy of F. bohemica is reappraised and expanded to produce a new anatomical in− terpretation. The previously distinct taxa F. pilosa and Furca sp., are synonymised with F. bohemica, the latter being rep− resented by a tapho−series in which decay has obscured some of the diagnostic features. A cladistic analysis indicates close affinities between F. bohemica and the Hunsrück Slate marrellomorph Mimetaster hexagonalis, together forming the Family Mimetasteridae, contrary to previous models for marrellomorph internal relationships. As with other repre− sentatives of the group, the overall anatomy of F. bohemica is consistent with a benthic, or possibly nektobenthic, mode of life. The depositional setting of the Letná Formation indicates that F. bohemica inhabited a shallow marine environment, distinguishing it palaeoecologically from all other known marrellomorphs, which have been reported from the continen− tal shelf.

The phylogeny of aglaspidid arthropods and the internal relationships within Artiopoda

“… Carapace outline: (0) genal spines; (1) acute genal angles; (2) rounded genal angles; (3) lateral spine‐like extensions of the carapace . State 3 refers to the conditions found in Marrella and Mimestaster (mediolateral spines sensu Rak et al., in press). Posterior cephalic band: (0) absent; (1) present (cf.…”

Stranger than a scorpion: a reassessment of Parioscorpio venator, a problematic arthropod from the Llandoverian Waukesha Lagerstätte

“…If the exopod setae of Marrella are not lamellate, but filamentous, as interpreted by Rak et al . (2013), then another trunk limb character is potentially shared between M. splendens and P. venator . The trunk exopods are clearly annulate in Marrella (García‐Bellido & Collins 2006, fig.…”

A late surviving xenopod (Arthropoda) from the Ordovican Period, Wales

“…Minor faunal elements include palaeoscolecids, lingulid brachiopods, conulariids, sponges and non-trilobite arthropods, the latter consisting primarily of ceratiocarid fragments, Etainia howellsorum gen. et sp. nov. and a taxon comparable to Furca bohemica from Ordovician deposits of the Czech Republic (Rak, Ortega-Hernández & Legg, 2013).…”