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Juelsminde, Denmark

Nielsen A.T.,Copenhagen University | Weidner T.,Ravnholtvej 23 | Terfelt F.,Lund University | Hoyberget M.,Rennesveien 14
GFF | Year: 2014

The traditional Furongian trilobite biozones of Scandinavia, recently proposed abandoned due to inconsistent boundary definitions [Terfelt, F., Eriksson, M.E., Ahlberg, P. & Babcock, L.E., 2008: Furongian Series (Cambrian) biostratigraphy of Scandinavia - a revision. Norwegian Journal of Geology88, 73-87], are resurrected and elevated to superzonal rank. These superzones are usually readily recognized in the field, even by non-specialists, and for general correlation and mapping the more wide-ranging biozones are considerably more practicable than the very detailed zonation (formerly subzonation) introduced by Terfelt et al. (2008). Formal definition of the superzones is outlined including designation of stratotype sections. The superzones are each defined by the FAD of a characterizing species group and upwards delimited by the base of the succeeding superzone. The long used Olenus, Parabolina and Leptoplastus (super)zones as well as the recently introduced Acerocarina Superzone (= Acerocare Zone of older literature) are maintained and formalized. The Protopeltura praecursor, Peltura minor and Peltura scarabaeoides zones are abandoned and replaced by two new units, named the Protopeltura and Peltura superzones, respectively. Accordingly, all Furongian superzones have a uniform naming style referring to a characteristic genus. The six Furongian superzones currently comprise 27 trilobite zones. The Paradoxides forchhammeri Superzone (Cambrian Series 3) is extended upwards to the base of the Olenus Superzone, thereby formally including the Agnostus pisiformis Zone. © 2014 © 2014 Taylor & Francis.

Weidner T.,Ravnholtvej 23 | Nielsen A.T.,Copenhagen University
Journal of Systematic Palaeontology | Year: 2014

A newly collected trilobite fauna from the lowermost part of the Alum Shale Formation at Øleå, Bornholm, Denmark, demonstrates the presence of a thin but richly fossiliferous Middle Cambrian Acidusus atavus Zone (Paradoxides paradoxissimus Superzone). The lower part of the zone (the Tomagnostus fissus-Ptychagnostus atavus Zone of older Scandinavian literature) is represented by a discontinuous limestone bed, up to 20 cm thick, whereas the upper part (Hypagnostus parvifrons Zone of older literature) is represented by shale, less than 80 cm thick, containing lenses of bituminous limestone. A total of 39 agnostid and 21 polymerid species are recorded from the A. atavus Zone (including 12 taxa treated under open nomenclature). One additional polymerid species collected from an ice-rafted boulder derived from the Bornholm area is also treated. The fauna is described and illustrated, with designation and reillustration of relevant lectotypes. The abundance of polymerid trilobites in comparison with nearby Scania, southern Sweden, where 25 agnostid and nine polymerid species have been reported from equivalent strata, is indicative of a less dysoxic environment in the Bornholm area, which was probably uplifted. The trilobite fauna resembles the coeval assemblages described from England, Wales, eastern Newfoundland and eastern Siberia, sharing several species not reported previously from Baltica, including Anopolenus sp., Agraulos longicephalus, Bailiella ornata, Clarella impar, Solenopleura? applanata, Acadagnostus aff. bulkurensis and Phalagnostus ovalis. A few faunal elements originally described from Bohemia and Australia are also present, viz. Hydrocephalus aff. carens, Phalagnostus nudus, Skryjagnostus pompeckji, Hypagnostus aff. clipeus, Euagnostus aff. interstrictus and Euagnostus? aff. glandifer. © The Trustees of the Natural History Museum, London 2013.

Weidner T.,Ravnholtvej 23 | Rushton A.W.A.,Natural History Museum in London | Ebbestad J.O.R.,Uppsala University
GFF | Year: 2014

We describe faunas, formerly very little known, from allochthonous mid-Cambrian strata in the Fjällbränna Formation (Tåsjön Group) in Ångermanland that are equivalent to the “Paradoxides oelandicus Beds” of the autochthon. Paradoxidid trilobites are by far the commonest forms but are represented only by dissociated sclerites; 7–10 taxa appear to be present, but most of them are so incomplete that they cannot be identified with certainty. They are accompanied by rare agnostoids of two taxa, Pentagnostus praecurrens and Acadagnostus acadicus. The assemblages lack eodiscoid or other polymerid trilobites, molluscs and brachiopods, and in this respect contrast with shallower-water shelf faunas in the “Oelandicus Beds” of the Swedish autochthon, but bear comparison with shelf-edge or slope faunas from Novaya Zemlya (Arctic Russia), the Moesian Platform (Romania) and South Carolina (USA). © 2014, © 2014 Taylor & Francis.

Rushton A.W.A.,Natural History Museum in London | Weidner T.,Ravnholtvej 23
GFF | Year: 2010

New material of Irvingella from central Sweden includes a cranidium of Irvingella major which is associated with fragmentary olenid trilobites that represent the Parabolina brevispina Subzone of the P. spinulosa Zone. This affords a direct correlation between the olenid trilobite zonation of Baltica and the Irvingella major Zone at the base of the Sunwaptan Stage in Laurentia. Several topotypic cranidia of Irvingella suecica Westerga°rd confirm the features of that species but do not provide a direct indication of its position within the olenid zonal succession.

Weidner T.,Ravnholtvej 23 | Nielsen A.T.,Copenhagen University
Bulletin of the Geological Society of Denmark | Year: 2015

The trilobite genus Agraulos Hawle & Corda 1847 has within Scandinavia been recorded only from Bornholm, Denmark, where its representatives occur in the Middle Cambrian Paradoxides paradoxissimus Superzone of the Alum Shale Formation. Only cranidia have been found so far, representing Agraulos longicephalus (Hicks 1872) and the rare “Agraulos” depressus Grönwall 1902. The two species from Bornholm are redescribed and discussed based on museum collections in combination with newly collected material from Borggård, Øleå. Agraulos longicephalus occurs commonly in the lower and upper part of the Acidusus atavus Zone as well as in the Ptychagnostus punctuosus Zone. It closely resembles the coeval Agraulos ceticephalus (Barrande 1846) known from Bohemia and eastern Newfoundland. A lectotype for “Agraulos” depressus is designated and reillustrated; this taxon is hesitantly assigned to Proampyx? It is known only from the Ptychagnostus punctuosus Zone and may represent an early, atypical Proampyx or maybe a precursor that should be separated in a new genus. Emended diagnoses of Agraulos Hawle & Corda 1847 and Proampyx Frech 1897 are presented. © 2014, Dansk Geologisk Forening. All rights reserved.

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