Reprint of: The Bohemo-Iberian regional chronostratigraphical scale for the Ordovician System and palaeontological correlations within South Gondwana JUAN CARLOS GUTIERREZ-MARCO, ARTUR A. SA, DIEGO C. GARCIA-BELLIDO AND ISABEL RABANO We are reprinting the above article in this special issue on ‘The contribution of fossils to chronostratigraphy, 150 years after Albert Oppel’ in issue 50:3 of Lethaia. The article was published in error in an earlier issue (Lethaia 50:2), and is reprinted here for ease and to complete the special issue. Furthermore, we have made a small correction to Figure 2 in this reprinted version of the article. The origi- nal published version had a missing label in the image. In the right-hand column, the text ‘Dobrotivian St’ should appear in the rectangle above the text ‘Oretanian St’; this has been corrected in this reprinted version of the article (and also in the online version of the article published in issue 50:2). Wiley would like to apologise to the Editors and authors for this error during production. For consistency, please continue to cite the article based on its original publication: Gutierrez-Marco, J.C., Sa, A.A., Garcıa-Bellido, D.C. & Rabano, I. 2017: The Bohemo-Iberian regional chronostratigraphical scale for the Ordovician System and palaeontological correlations within South Gond- wana. Lethaia 50, 258–295. doi: 10.1111/let.12197. DOI 10.1111/let.12216 © 2017 Lethaia Foundation. Published by John Wiley & Sons Ltd The Bohemo-Iberian regional chronostratigraphical scale for the Ordovician System and palaeontological correlations within South Gondwana JUAN CARLOS GUTIERREZ-MARCO, ARTUR A. SA, DIEGO C. GARCIA-BELLIDO AND ISABEL RABANO Gutierrez-Marco, J.C., Sa, A.A., Garcıa-Bellido, D.C. & Rabano, I. 2017: The Bohemo- Iberian regional chronostratigraphical scale for the Ordovician System and palaeontological correlations within South Gondwana. Lethaia, Vol. 50, pp. 258–295. Abstract The Bohemo-Iberian regional scale for South Gondwana, involving the ‘Mediter- ranean Province’, comprises five regional stages (Arenigian, Oretanian, Dobrotivian, Berounian and Kralodvorian) plus the global Tremadocian and Hirnantian. The predominance of shallow-water taxa in those high-latitude faunas imposes serious dif- ficulties for correlating the regional succession with the formal global chronostratigra- phy because of the almost total absence of the key graptolites and conodonts defining the base of the standard series, stages and stage slices. Instead, the abundant benthic faunas (trilobites, brachiopods, molluscs, echinoderms) of South Gondwanan origin largely dominated in the area from the middle Darriwilian to the late Katian. The poleward faunal migration of originally Avalonian, Baltic, Laurentian and even Asiatic taxa during the Boda Event of global warming progressively ends with the endemicity in the region, where the ensuing benthic assemblages were severely affected by the Hir- nantian glaciation. The regional scale significantly improves the precision of correla- tions between Ordovician strata from SW and central Europe, North Africa and a large part of the Middle East. An updated record of palaeontological data from areas where Mediterranean faunas remain practically unknown, or are still poorly investi- gated, is also included. Palaeobiogeographical relationships based on the distribution of faunas across South Gondwana are suggested as an improvement for positioning many territories in modern palaeogeographical reconstructions and offer a construc- tive approach to problems related to the pre-Variscan and pre-Alpine orogenic puz- zles. □ Ordovician, Palaeobiogeography, Regional chronostratigraphy, South Gondwana. Juan Carlos Gutierrez-Marco ✉ [[email protected]], Instituto de Geociencias CSIC, UCM and Departamento de Paleontologıa, Facultad de Ciencias Geologicas, Jose Antonio Novais 12, 28040 Madrid, Spain; Artur A. Sa [[email protected]], Departamento de Geologia, Universidade de Tras-os-Montes e Alto Douro, Quinta de Prados 5001-801 Vila Real, Portugal; Artur A. Sa [[email protected]], Centro de Geoci^encias, Universidade de Coimbra, Polo II 3030-790 Coimbra, Portugal; Diego C. Garcıa-Bellido [Diego.Garcia-Bellido@ adelaide.edu.au], Department of Biological Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia; Isabel Rabano [[email protected]], Museo Geominero, Instituto Geologico y Minero de Espana,~ Rıos Rosas 23, 28003 Madrid, Spain; manuscript received on 13/02/2016; manuscript accepted on 16/09/2016. In the Prague Basin, and well before the establish- century, the traditional British Ordovician scheme ment of the Ordovician System by Lapworth (1879), persisted as a kind of ‘lingua franca’ for Ordovician the French palaeontologist Joachim Barrande (1799– chronostratigraphy (Webby 1998). However, the 1883) recognized the separate character of the Bohe- high faunal endemicity that characterized this period mian Ordovician faunas by the definition of a regio- at a global scale made it difficult to achieve a detailed nal stage (‘etage D’, Barrande 1846) within the set of correlation criteria, especially those arising extent assigned by him to the ‘Silurian system’ of from both the traditional and revised British series Murchison (1839). This ‘Stage D’ was later docu- and stages. This favoured the proliferation of a num- mented (Barrande 1852) and subdivided into five ber of regional chronostratigraphical units (includ- ‘bands’, which comprise the current Lower and Mid- ing regional series, stages, substages and ‘horizons’) dle Ordovician series (‘bande d1’) and the Upper developed during the twentieth century in parallel to Ordovician one (‘bandes d2–5’), based on the distri- the British scale, for a more effective interregional bution of his so-called Second Fauna. correlation. These are the successful regional This original local Bohemian classification was schemes developed for Australia–New Zealand, not recognized internationally, and for more than a Baltoscandia (essentially based on the Estonian DOI 10.1111/let.12197 © 2016 Lethaia Foundation. Published by John Wiley & Sons Ltd LETHAIA 50 (2017) Bohemo-Iberian regional chronostratigraphical scale 259 classification), China, North America, Russia– REVISED ORDOVICIAN BRITISH-AVALONIAN Kazakhstan (with at least six scales for different CHRONOSTRATIGRAPHY REGIONAL SCALE Ordovician basins or structural provinces) and the (Williamset al. 1972, (Forteyet al. 1995, peri-Gondwanan Mediterranean area (Webby 1998 Harlandet al. 1982) Cockset al. 2010) and references therein). At the same time a consider- able effort by British workers to produce a more Hirnantian Hirnantian standardized scheme based on traditional stratotypes Rawtheyan Rawtheyan led to the discovery of significant stratigraphical gaps ASHGILL or overlaps of the widely used units (Finney 2005). Cautleyan Cautleyan This also generated a conceptual evolution of the ASHGILL former scale (Fig. 1) into a substantially modified Pusgillian Pusgillian et al. scheme (Gutierrez-Marco 2016; with previous Onnian Onnian references). The refined British scheme (Fortey et al. Streffordian 1995, 2000) did not satisfy the international correla- Actonian Actonian Marshbrookian Marshbrookian tion requirements to become the global standard Cheneyan Woolstonian and is today considered a regional scale applicable CARADOC Longvillian for East Avalonia (including the Anglo-Welsh area, Longvillian southern Ireland and Belgium) and parts of northern SoudleyanBurrellian Soudleyan Germany and NW Poland (‘Far Eastern Avalonia’). Harnagian CARADOC Harnagian To avoid these widespread problems for interconti- nental correlation, the International Commission on Costonian Costonian Stratigraphy (IUGS) first completed in 2007 the for- Upper Aurelucian Velfreyan mal chronostratigraphical classification for the LLANDEILO Middle Ordovician System, introducing a threefold division into Lower, Middle and Upper series and seven new Lower Llandeilian global stages. Among these, only the Tremadocian and Hirnantian stages were adopted from the existing Upper LLANVIRN British names, but their basal global stratotypes were Abereiddian located in Canada and China, respectively (Harper Lower LLANVIRN 2011; Cooper & Sadler 2012). The ‘golden spikes’ for Upper the new series and stage boundaries were placed in Fennian deep-water facies within continuous and fossiliferous sections, coinciding with the first appearance datum no stages defined (FAD) of particular conodont and graptolite species ARENIG Whitlandian Lower of worldwide distribution. However, the majority of ARENIG these cosmopolitan taxa (or their FADs) can hardly be recognized in the strata of the extensive shallow- Moridunian water, inner-shelf environments and epicontinental seas that surrounded Gondwana, Baltica and Siberia palaeocontinents. Here, the poor applicability of the Migneintian standard scale is compensated by the capacity of regional scales to obtain more precise local to interre- TREMADOC gional correlations. This is the reason why, in agree- Cressagian ment with the Ordovician Subcommission, an TREMADOC increasing refinement of the regional scales could provide a fundamental contribution to the develop- Fig. 1. Correlation between the former ‘modern’ view for British Ordovician chronostratigraphy, and the present-day British– ment of a better global chronostratigraphy Avalonian regional scale. (Bergstrom€ et al. 2009; Harper 2011). This paper examines the present status of the Bohemo-Iberian (= ‘Mediterranean’) regional Palaeogeographical setting