Topic
Olenus
About: Olenus is a research topic. Over the lifetime, 34 publications have been published within this topic receiving 638 citations.
Papers
TL;DR: The Andrarum-3 core was used in this paper for core drilling in Scania, Sweden, where trilobites and phosphatocopines were used to subdivide the core into seven biozones ranging from the Ptychagnostus atavus Zone to the Parabolina spinulosa Zone.
Abstract: A core drilling (Andrarum-3), from the classical locality at Andrarum, Scania, southernmost Sweden, penetrated a 28.90-m-thick Cambrian succession. The core comprises dark grey to black, finely laminated mudstones and shales with early concretionary carbonate lenses (stinkstones or orsten) and a few primary carbonate beds. The middle Cambrian (provisional Series 3) part of the core comprises 17.35 m, whereas the Furongian Series (upper Cambrian) part covers the remaining 11.55 m. Nineteen trilobite and two phosphatocopine genera are present in the middle Cambrian, whereas the less diverse Furongian interval yielded four trilobite and three phosphatocopine genera. Other, less frequent, faunal elements include conodonts (s. l.), brachiopods, sponge spicules, bradoriids, and coprolites. Trilobites and phosphatocopines were used to subdivide the core into seven biozones ranging from the Ptychagnostus atavus Zone to the Parabolina spinulosa Zone (P. spinulosa Subzone). Carbon isotopic analyses (δ13Corg) through the core show two important excursions, the negative DrumIan Carbon isotope Excursion (DICE) in the Pt. atavus Zone, and the Steptoean Positive Carbon Isotope Excursion (SPICE) beginning near the first appearance of Glyptagnostus reticulatus and extending upward into the Olenus and Agnostus (Homagnostus) obesus Zone. The DICE displays a peak value, in the samples at hand, of –30.45‰δ13Corg in the lower part of the P. atavus Zone. The δ13Corg values increase through the overlying L. laevigata and A. pisiformis zones and display peak values of c. –28.00‰δ13Corg in the lowermost Furongian Olenus wahlenbergi and O. attenuatus subzones. Thereafter the values decrease significantly through the O. scanicus Subzone. Both isotopic excursions have been documented from several palaeocontinents, but never before from Baltica. Moreover, for the first time these excursions are recorded from organic matter in an alum shale setting. The recorded shift of +1.50–2.00‰δ13Corg is approximately half the magnitude of the SPICE documented from other regions. This discrepancy may be related to temporal variations in the type, origin, or diagenesis of the organic fraction analysed.
121 citations
TL;DR: The upper Cambrian faunas of Scandinavia are generally dominated by olenid trilobites, which provide a firm basis for the biostratigraphic classification as mentioned in this paper.
Abstract: The Upper Cambrian faunas of Scandinavia are generally dominated by olenid trilobites, which provide a firm basis for the biostratigraphic classification. The olenids tend, however, to be provincial and facies controlled. By contrast, many agnostoid genera and species have a nearly worldwide distribution and are excellent biostratigraphic indices in Middle and Upper Cambrian strata. Three distinctive and geographically widely distributed agnostoid species are known from the lower part of the Upper Cambrian in Scandinavia: Linguagnostus reconditus POLETAEVA and ROMANENKO, 1970, Aspidagnostus lunulosus (KRYSKOV in Borovikov and Kryskov, 1963), and Glyptagnostus reticulatus (ANGELIN, 1851). They are the most valuable species available for correlations with Upper Cambrian deposits outside Baltica. L. reconditus is seemingly confined to the Agnostus pisiformis Zone and provides strong evidence for correlation of that zone with the recently defined L. reconditus Zone of Peng and Robison. G. reticulatus appears in the Olenus gibbosus Subzone and ranges up into the O. wahlenbergi Subzone, suggesting that the lower part of the Olenus/Agnostus (Homagnostus) obesus Zone correlates with the G. reticulatus Zone in, e.g., Australia, China, and Kazakhstan. The presence of A. lunulosus in the O. gibbosus Subzone provides additional evidence for this correlation. Higher in the sequence agnostoids become rare, and the species recorded from the medial and upper Upper Cambrian of Baltica permit only broad correlations with other continents.
50 citations
TL;DR: Ahlberg et al. as mentioned in this paper described fourteen agnostid species from the Upper Cambrian of Vastergotland, Sweden and assigned them to eleven genera: Agnostus, Homagnostus and T. holmi.
Abstract: Fourteen agnostid species are described from the Upper Cambrian of Vastergotland, Sweden. They are assigned to eleven genera: Agnostus, Homagnostus, Trilobagnostus, Lotagnostus, Kormagnostus, Glyptagnostus, Hypagnostus, Peratagnostus, Cristagnostus, Pseudagnostus, and Aspidagnostus. Cristagnostus and Aspidagnostus have not previously been recorded from Scandinavia. The majority of the species are from the lower part of the Upper Cambrian, i.e., the Agnostus pisiformis, the Olenus and Homagnostus obesus, and the Parabolina spinulosa Zones. Agnostids are very rare in the upper part and only three species seem to be represented, viz. Trilobagnostus rudis, T. holmi, and Lotagnostus trisectus. Ahlberg, P. & Ahlgren, J., 1996: Agnostids from the Upper Cambrian of Vastergotland, Sweden. GFF, Vol. 118 (Pt. 3, September), pp. 129–140. Stockholm. ISSN 1103–5897.
50 citations
Journal Article•
TL;DR: In this article, a modified version of the Upper Cambrian biostratigraphic zonation established for the Baltica-palaeocontinent was used for the revision of the Late Cambrian trilobites from Łysogory in central Poland.
Abstract: Revision of the Late Cambrian trilobites from Łysogory in the Holy Cross Mountains, central Poland, enabled the application of a modified version of the Upper Cambrian biostratigraphic zonation established for the Baltica palaeocontinent. The following zones and subzones were recognised: Olenus scanicus and Parabolina brevispina subzones, Leptoplastus − Protopeltura praecursor Zone, Peltura minor Zone ( Ctenopyge tumida and Ctenopyge affinis subzones), Peltura scarabaeoides Zone ( Ctenopyge linnarssoni and ? Parabolina lobata subzones) and the Acerocare Zone sensu lato. Biogeographically the trilobites of Lysogory show a distinct change, from a low diversity fauna with a predominance of Avalonian forms in the early Late Cambrian, to more diversified assemblages, characterised by the constant increase to dominance of Baltic elements by the end of the Cambrian.
42 citations
TL;DR: The upper Cambrian trilobite Olenus wahlenbergi Westergard as discussed by the authors was found in stinkstone concretions in the Alum Shales at Andrarum, in Skane, southern Sweden (Olenus/Homagnostus obesus Zone).
Abstract: The upper Cambrian trilobite Olenus wahlenbergi Westergard, 1922 occurs abun- dantly in stinkstone concretions in the Alum Shales at Andrarum, in Skane, southern Sweden (Olenus/Homagnostus obesus Zone). All growth stages from anaprotaspis onwards are represented, though the early stages are comparatively uncommon and complete specimens are rare. Fine details of structure are preserved, suitable for scanning electron microscopic study.The protaspis has five axial rings, which in the adult become divided transversely and reduced to three, and the preglabellar field expands markedly in the holaspis. The librigena broadens during development and the eye, with its widely separated lenses is retained on the librigena throughout meraspid development. The visual surface dehisces during ecdysis from the early holaspid onwards, due to emplacement of the ocular suture. The hypostome apparently changes from a conterminant to a natant condition in the early holaspis, which is consistent with the growth of the preglabellar field at this stage. The transitory pygidium has a slightly serrated margin throughout development, but becomes entire when all thoracic segments have been liberated.Cuticular sculpture changes dramatically throughout ontogeny. Large (Type A) tubercles appear on the fixigena in early meraspides; these become prominent and coalesce by the end of meraspid development. They are abruptly replaced by smaller (Type B) tubercles in the early holaspid, which link to form a rough network in mature specimens. Comparable Type A tubercles in early meraspid librigenae give rise to a strong polygonal caecal sculpture in holaspids, while a radial sculpture on the broadening anterior border develops independently. The significance of these cuticular changes remains obscure. A median occipital organ is described for the first time in the Olenidae.
40 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2019 | 1 |
| 2017 | 1 |
| 2016 | 2 |
| 2014 | 3 |
| 2013 | 1 |