Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-26T19:00:22.982Z Has data issue: false hasContentIssue false
  • English
  • Français

A graptolite-rich Ordovician–Silurian boundary section in the south-central Pyrenees, Spain: stratigraphical and palaeobiogeographical significance

Published online by Cambridge University Press:  29 June 2018

PETR ŠTORCH ,
JOSEP ROQUÉ BERNAL  and
JUAN CARLOS GUTIÉRREZ-MARCO
PETR ŠTORCH*
Affiliation:
Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, 165 00, Praha 6, Czech Republic
JOSEP ROQUÉ BERNAL
Affiliation:
Sant Benilde 8, 2° 1ª, 43006 Tarragona, Spain
JUAN CARLOS GUTIÉRREZ-MARCO
Affiliation:
Instituto de Geociencias (CSIC, UCM), Dr. Severo Ochoa 7 planta 4, 28040 Madrid, and Departamento de Geodinámica, Estratigrafía y Paleontología, Facultad CC. Geológicas UCM, José Antonio Novais 12, 28040 Madrid, Spain
*
†Author for correspondence: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

An Ordovician–Silurian boundary section marked by an uninterrupted, relatively high rate of black shale sedimentation and abundant, diverse graptolites is described from the south-central Pyrenees. The structurally simple Estana section comprises the uppermost part of the quartzite-dominated Bar Formation and overlying black shales of late Hirnantian and early Rhuddanian age, which have been dated by graptolites to the upper Metabolograptus persculptus and lower–middle Akidograptus ascensus–Parakidograptus acuminatus biozones. Due to the absence of M. persculptus, a Metabolograptus parvulus Biozone correlative with the upper part of the persculptus Biozone is recognized below the lowest occurrence of akidograptids, which indicate the base of the Silurian System. The graptolite fauna comprise 27 species including Normalograptus minor, N. lubricus, N. rhizinus, Hirsutograptus, Korenograptus bifurcus, K. bicaudatus, K. lanpherei and Nd. shanchongensis, most of which were formerly considered to be endemic to the low-latitude palaeobiogeographical province of China, Siberia and northern North America. Two new species, N. baridaensis and N. ednae, are described. The succession of graptolite assemblages in the Estana section, and occurrence of several cosmopolitan taxa in its parvulus and lower ascensus–acuminatus biozones that are unknown elsewhere in peri-Gondwanan Europe, suggest that strata immediately surrounding the Ordovician–Silurian boundary may be absent, highly condensed or oxic and barren of graptolites in other sections of northwestern peri-Gondwana. Common graptolite synrhabdosomes and abnormal rhabdosomes may indicate some environmental stress in the parvulus Biozone, although the rather uniform black shale lithology, total organic carbon content and δ13Corg values suggest uninterrupted sedimentation under stable, anoxic conditions.

Keywords

Ordovician–Silurian boundarygraptolitesbiostratigraphycarbon isotopesabnormal astogeny
Type
Original Article
Information
Geological Magazine , Volume 156 , Issue 6 , June 2019 , pp. 1069 - 1091
Copyright
Copyright © Cambridge University Press 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bergström, S. M., Huff, W. D., Korenʼ, T. N., Larsson, K., Ahlberg, P. & Kolata, D. R. 1999. The 1997 core drilling through Ordovician and Silurian strata in Röstanga, S. Sweden: preliminary stratigraphic assessment and regional comparison. GFF 121, 127–35.CrossRefGoogle Scholar
Bjerreskov, M. 1975. Llandoverian and Wenlockian graptolites from Bornholm. Fossils and Strata 8, 1–94.Google Scholar
Blackett, E., Page, A., Zalasiewicz, J., Williams, M., Rickards, B. & Davies, J. 2009. A refined graptolite biostratigraphy for the late Ordovician – early Silurian of central Wales. Lethaia 42, 83–96.CrossRefGoogle Scholar
Boissevain, H. 1934. Étude géologique et géomorphologique d'une partie de la vallée de la Haute Sègre (Pyrénées Catalanes). Bulletin de la Société d'Histoire Naturelle de Toulouse 66, 33–170.Google Scholar
Casas, J. M. 2010. Ordovician deformations in the Pyrenees: new insights into the significance of pre-Variscan (‘sardic’) tectonics. Geological Magazine 147, 674–89.CrossRefGoogle Scholar
Casas, J. M. & Palacios, T. 2012. First biostratigraphical constraints on the pre-Upper Ordovician sequences of the Pyrenees based on organic-walled microfossils. Comptes Rendus Geoscience 344, 50–6.CrossRefGoogle Scholar
Casas, J.M., Puddu, C. & Álvaro, J. J. 2017. Fieldtrip to eastern Pyrenees, Catalonia and Occitanie, Stop 7a. Upper Ordovician succession in Talltendre. Géologie de la France 2017 (1), 43–6.Google Scholar
Chaletskaya, O. N. 1960. New species of the Llandovery graptolites of Central Asia. In Novye Vidy Drevnikh Rastenii i Bespozvonochnykh SSSR, Chast 2. (ed. Markovsky, B. P.), pp. 373–5. Moskva: Gosudarstvennoe Naucho-teknicheskoje Izdatelstvo [in Russian].Google Scholar
Chen, X., Fan, J. X., Melchin, M. J. & Mitchell, C. E. 2005. Hirnantian (latest Ordovician) graptolites from the Upper Yangtze Region, China. Palaeontology 48, 235–80.Google Scholar
Chen, X. & Lin, Y. K. 1978. Lower Silurian graptolites from Tongzi, northern Guizhou. Memoir of the Nanjing Institute of Geology and Palaeontology, Academia Sinica 12, 1–106 [in Chinese with English abstract].Google Scholar
Chen, X., Rong, J. Y. & Fan, J. X. 2003. A proposal for a candidate section for restudy of the base of Silurian. In Proceedings of the 7th International Graptolite Conference and Field Meeting of the ISSS (eds G. Ortega & G. F. Aceñolaza), pp. 119–23. INSUGEO, Serie Correlación Geológica 18.Google Scholar
Chen, X., Rong, J. Y., Mitchell, C. E., Harper, D. A. T., Fan, J. X., Zhan, R. B., Zhang, Y. D., Li, R. Y. & Wang, Y. 2000. Late Ordovician to earliest Silurian graptolite and brachiopod biozonation from the Yangtze region, South China, with a global correlation. Geological Magazine 137, 623–50.Google Scholar
Churkin, Jr M. & Carter, C. 1970. Early Silurian graptolites from southeastern Alaska and their correlation with graptolitic sequences in North America and the Arctic. United States Geological Survey Professional Paper 653, 1–51.Google Scholar
Colmenar, J. 2015. The arrival of brachiopods of the Nicolella community to the Mediterranean margin of Gondwana during the Late Ordovician: palaeogeographical and palaeoecological implications. Palaeogeography, Palaeoclimatology, Palaeoecology 428, 12–20.CrossRefGoogle Scholar
Dalloni, M. 1930. Étude géologique des Pyrénées Catalanes. Annales de la Faculté des Sciences de Marseille 26, 1–373.Google Scholar
Davies, K. A. 1929. Notes on the graptolite faunas of the Upper Ordovician and Lower Silurian. Geological Magazine 66, 1–27.CrossRefGoogle Scholar
Dégardin, J.-M. 1988. Le Silurien des Pyrénées. Biostratigraphie. Paléogéographie. Société Géologique du Nord, Publication 15, 506 pp.Google Scholar
Dégardin, J.-M. 1990. The Silurian of the Pyrenees. Journal of the Geological Society 147, 687–92.CrossRefGoogle Scholar
Dégardin, J. M. (coord.), Alonso, J. L., Bessière, G., Bodin, J., Bouquet, G., Brula, P., Centène, A., Duran, H., Garces-Cocchio, A. M., García-López, S., García-Sansegundo, J., Guérangé, B., Julivert, M., Laumonier, B., Losantos, M., Palau, J., Paris, F., Pouit, G., Raymond, D., Richard, P., Sanz, J., Truyols-Massoni, M. & Villas, E. 1996. Ordovicien Supérieur – Silurien. In Synthèse Géologique et Géophysique des Pyrénées (eds Barnolas, A. & Chiron, J. C.), pp. 211–33. Instituto Geológico y Minero de España, Bureau de Recherches Géologiques et Minières.Google Scholar
Delabroye, A., Munnecke, A., Servais, T., Vandenbroucke, T. R. A. & Vecoli, M. 2012. Abnormal forms of acritarchs (phytoplankton) in the upper Hirnantian (Upper Ordovician) of Anticosti Island, Canada. Review of Palaeobotany and Palynology 173, 46–56.CrossRefGoogle Scholar
Elles, G. L. & Wood, E. M. R. 1907. A Monograph of British Graptolites. Part 6. Palaeontographical Society, London, Monograph no. 61(297), 217–72.Google Scholar
Fan, J. X., Melchin, M. J. & Williams, S. H. 2005. Restudy of the Hirnantian (latest Ordovician) graptolites from Dob's Linn, southern Scotland. In Abstracts for the Second International Symposium of IGCP 503 on Ordovician Palaeogeography and Palaeoclimate (eds Sheehan, P. T. & Servais, T.), pp. 7–8. Milwaukee Public Museum Series in Natural History no. 2.Google Scholar
Fan, J. X., Peng, P. & Melchin, M. J. 2009. Carbon isotopes and event stratigraphy near the Ordovician–Silurian boundary, Yichang, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 276, 160–9.CrossRefGoogle Scholar
Gil-Peña, I. & Barnolas, A. 2007. A review of the Ordovician sequence in the Pyrenean Axial Zone and the Catalonian Coastal Ranges, NE Iberia. In IGCP Project 503. Regional Meeting and Fieldtrip, pp. 11–12. Publicaciones Universidad de Zaragoza.Google Scholar
Gil-Peña, I., Barnolas, A., Sanz-López, J., García-Sansegundo, J. & Palau, J. 2001. Discontinuidad sedimentaria del Ordovícico terminal en los Pirineos centrales. Geogaceta 29, 57–60.Google Scholar
Gil-Peña, I., Barnolas, A., Villas, E. & Sanz-López, J. 2004. El Ordovícico Superior de la Zona Axial. In Geología de España (ed. Vera, J. A.), pp. 247–9. Madrid: SGE-IGME.Google Scholar
Gogin, I. J., Koren’, T. N., Pegel’, T. V. & Sobolevskaya, R. F. 1997. Atlas zonalnykh kompleksov veduschikh grup rannepaleozoiskoy fauny severa Rossii. Sankt-Petersburg: Izdatelstvo VSEGEI, 205 pp. [in Russian].Google Scholar
Gutiérrez-Marco, J. C. & Lenz, A. C. 1998. Graptolite synrhabdosomes: biological or taphonomic entities? Paleobiology 24, 37–48.CrossRefGoogle Scholar
Gutiérrez-Marco, J. C. & Robardet, M. 1991. Découverte de la Zone à Parakidograptus acuminatus (base du Llandovery) dans le Silurien du Synclinorium de Truchas (Zone asturo-léonaise, Nord-Ouest de l'Espagne): consequences stratigraphiques et paléogéographiques au passage Ordovicien–Silurien. Comptes Rendus de l'Academie des Sciences, Paris, Série H 312, 729–34.Google Scholar
Hartevelt, J. J. A. 1970. Geology of the Upper Segre and Valira valleys, central Pyrenees, Andorra/Spain. Leidse Geologische Mededeelingen 45, 167–236.Google Scholar
Huang, Z. G. 1982. Latest Ordovician and earliest Silurian graptolite assemblages of Xainza district, Xizang (Tibet) and Ordovician-Silurian boundary. In Contribution to the Geology of the Qinghai-Xizang (Tibet) Plateau, 7. (eds Editorial Committee of Ministry of Geology and Mineral Resources), pp. 27–52. Beijing: Geological Publishing House [in Chinese with English abstract].Google Scholar
Hutt, J. E. 1974. The Llandovery Graptolites of the English Lake District. Part 1. Palaeontographical Society, London, Monograph no. 128(540), 1–56.Google Scholar
Institut Geològic de Catalunya and Institut Cartogràfic de Catalunya (ed.) 2010. Atles Geològic de Catalunya. Barcelona: Instytut Cartogràfic de Catalunya, 463 pp.Google Scholar
Jaeger, H. 1977. Das Silur/Lochkov-Profil im Frankenberger Zwischengebirge (Sachsen). Freiberger Forschungshefte, C 326, 45–59.Google Scholar
Jaeger, H., Havlíček, V. & Schönlaub, H.-P. 1975. Biostratigraphie der Ordovizium/Silur Grenze in den Südalpen – Ein Beitrag zur Diskussion um die Hirnantia-Fauna. Verhandlungen der Geologischen Bundesanstalt 1975, 271–89.Google Scholar
Jaeger, H. & Robardet, M. 1979. Le Silurien et le Devonien basal dans le nord de la province de Séville (Espagne). Geobios 12, 687–714.CrossRefGoogle Scholar
Jin, C. T., Ye, S. H., He, Y. X., Wan, Z. Q., Wang, S. B., Zhao, Y. T., Li, S. J., Xu, X. Q. & Zhang, Z. Q. 1982. The Silurian Stratigraphy and Palaeontology in Guanyinqiao, Qijiang, Sichuan. Chengdu: People's Publishing House of Sichuan, 84 pp. [in Chinese with English abstract].Google Scholar
Korenʼ, T. N., Ahlberg, P. & Nielsen, A. T. 2003. The post-persculptus and pre-ascensus graptolite fauna in Scania, south-western Sweden: Ordovician or Silurian? In Proceedings of the 7th International Graptolite Conference and Field Meeting of the ISSS (eds Ortega, G. & Aceñolaza, G. F.), pp. 133–8. INSUGEO, Serie Correlación Geológica 18.Google Scholar
Koren’, T. N. & Bjerreskov, M. 1997. Early Llandovery monograptids from Bornholm and the southern Urals: taxonomy and evolution. Bulletin of the Geological Society of Denmark 44, 1–43.Google Scholar
Korenʼ, T. N. & Melchin, M. J. 2000. Lowermost Silurian graptolites from the Kurama Range, eastern Uzbekistan. Journal of Paleontology 74, 1093–113.2.0.CO;2>CrossRefGoogle Scholar
Koren’, T. N. & Rickards, R. B. 1996. Taxonomy and evolution of Llandovery biserial graptoloids from the southern Urals, western Kazakhstan. Special Papers in Palaeontology 54, 1–103.Google Scholar
Krstič, B., Maslarevič, L. & Sudar, M. 2005. On the Graptolite Schists Formation (Silurian – Lower Devonian) in the Carpatho-Balkanides of eastern Serbia. Annales Géologiques de la Péninsule Balkanique 66, 1–8.Google Scholar
Lakova, I. & Sachanski, V. 2004. Cryptospores and trilite spores in oceanic graptolite-bearing sediments (Saltar Formation) across the Ordovician–Silurian boundary in the West Balkan Mountains, Bulgaria. Review of the Bulgarian Geological Society 65, 151–6.Google Scholar
Lapworth, H. 1900. The Silurian sequence of Rhayader. Quarterly Journal of the Geological Society of London 56, 67–137.CrossRefGoogle Scholar
Legrand, P. 1977. Contribution à l'etude des graptolites du Llandoverien inferieur de l'Oued In Djerane (Tassili N'ajjer oriental, Sahara algérien). Bulletin de la Société d'Histoire Naturelle de l'Afrique du Nord 67, 141– 96.Google Scholar
Li, J. J. 1984. Graptolites across the Ordovician–Silurian boundary from Jingxian, Anhui. In Stratigraphy and Palaeontology of Systemic Boundaries in China. Ordovician-Silurian Boundary (1) (eds Nanjing Institute of Geology and Palaeontology), pp. 309–70. Hefei: Anhui Science and Technology Publishing House.Google Scholar
Loxton, J. D. 2017. Graptolite diversity and community changes surrounding the Late Ordovician mass extinction: high resolution data from the Blackstone River, Yukon. PhD thesis, Dalhousie University, Halifax, Canada. Published thesis.Google Scholar
Loydell, D. K. 2007. Graptolites from the Upper Ordovician and lower Silurian of Jordan. Special Papers in Palaeontology 78, 1–66.Google Scholar
Loydell, D. K., Mallett, A., Mikulic, D. G., Kluessendorf, J. & Norby, R. D. 2002. Graptolites from near the Ordovician–Silurian boundary in Illinois and Iowa. Journal of Paleontology 76, 134–7.CrossRefGoogle Scholar
Manck, F. 1923. Untersilurische Graptolithenarten der Zone 10, ferner Diversograptus gen. nov., sowie einige neue Arten anderer Gattungen. Die Natur 14, 282–9.Google Scholar
Margalef, A., Castiñeiras, P., Casas, J. M., Navidad, M., Liesa, M., Linnemann, U., Hofmann, M. & Gärtner, A. 2016. Detrital zircons from the Ordovician rocks of the Pyrenees: geochronological constraints and provenance. Tectonophysics 681, 124–34.CrossRefGoogle Scholar
Masiak, M., Podhałańska, T. & Stempień-Sałek, M. 2003. Ordovician – Silurian boundary in the Bardo Syncline (Holy Cross Mountains) – new data on fossil assemblages and sedimentary succession. Geological Quarterly 47, 311–29.Google Scholar
Melchin, M. J. 1989. Llandovery graptolite biostratigraphy and paleobiogeography, Cape Phillips Formation, Canadian Arctic Islands. Canadian Journal of Earth Sciences 26, 1726–46.CrossRefGoogle Scholar
Melchin, M. J. 2001. The GSSP for the base of the Silurian System. Silurian Times 9, 36–41.Google Scholar
Melchin, M. J. 2003. Restudying a global stratotype for the base of the Silurian: a progress report. In Proceedings of the 7th International Graptolite Conference and Field Meeting of the ISSS (eds Ortega, G. & Aceñolaza, G. F.), pp. 147–9. INSUGEO, Serie Correlación Geológica 18.Google Scholar
Melchin, M. J., McCracken, A. D. & Oliff, F. J. 1991. The Ordovician–Silurian boundary on Cornwallis and Truro islands, Arctic Canada: preliminary data. Canadian Journal of Earth Sciences 28, 1854–62.CrossRefGoogle Scholar
Melchin, M. J., Mitchell, C. E., Holmden, C. & Štorch, P. 2013. Environmental changes in the Late Ordovician–early Silurian: review and new insights from black shales and nitrogen isotopes. The Geological Society of America Bulletin 125, 1635–70.CrossRefGoogle Scholar
Melchin, M. J., Mitchell, C. E., Naczk-Cameron, A., Fan, J. X. & Loxton, J. 2011. Phylogeny and adaptive radiation of the Neograptina (Graptoloida) during the Hirnantian mass extinction and Silurian recovery. Proceedings of the Yorkshire Geological Society 58, 281–309.CrossRefGoogle Scholar
Mitchell, C. E. 1987. Evolution and phylogenetic classification of the Diplograptacea. Palaeontology 30, 353–405.Google Scholar
Mu, E. Z., Li, J. J., Ge, M. Y., Lin, Y. K. & Ni, Y. N. 2002. Graptolites of China. Beijing: Science Press, 1205 pp. [in Chinese].Google Scholar
Muir, L. A. 2011. An unusual specimen of Glyptograptus from Dob's Linn (Southern Uplands, Scotland), and a discussion of graptolite teratomorphies. Proceedings of the Yorkshire Geological Society 58, 311–7.CrossRefGoogle Scholar
Munnecke, A., Delabroye, A., Servais, T., Vandenbroucke, T. R. A. & Vecoli, M. 2012. Systematic occurrences of malformed (teratological) acritarchs in the run-up of Early Palaeozoic δ13C isotope excursions. Palaeogeography, Palaeoclimatology, Palaeoecology 367–368, 137–46.CrossRefGoogle Scholar
Nanjing Institute of Geology and Mineral Resources (ed.) 1983. Palaeontological Atlas of East China, I. Early Palaeozoic. Beijing: Geological Publishing House, 657 pp. [in Chinese].Google Scholar
Nanjing Institute of Geology and Palaeontology (ed.) 1974. A Handbook of Stratigraphy and Palaeontology of South-West China. Beijing: Science Press, 454 pp. [in Chinese].Google Scholar
Nicholson, H. A. 1867. On some fossils from the Lower Silurian rocks of the south of Scotland. Geological Magazine 1, 107–13.CrossRefGoogle Scholar
Nicholson, H. A. 1868. On the nature and zoological position of the Graptolitidae. Annals and Magazine of Natural History 1, 55–61.CrossRefGoogle Scholar
Obut, A. M., Sobolevskaya, R. F. & Nikolaev, A. A. 1967. Graptolites and Stratigraphy of the Lower Silurian along the Margins of the Kolyma Massif. Akademiya Nauk SSR, Sibirskoje Otdelenie, Institut Geologii i Geofiziki. Ministerstvo Geologii SSSR, Nauchno-Issledovatel'sky Institut Geologii Arktiki, 164 pp. [in Russian].Google Scholar
Perner, J. 1895. Études sur les Graptolites de Bohême. IIième Partie. Monographie des Graptolites de l’Étage D. Prague: Raimond Gerhard, 31 pp.Google Scholar
Piçarra, J. M., Robardet, M., Oliveira, J. T., Paris, F. & Lardeux, H. 2009. Graptolite faunas of the Llandovery “phtanites” at Les Fresnaies (Chalonnes-sur-Loire, southeastern Armorican Massif): palaeontology and biostratigraphy. Bulletin of Geosciences 84, 41–50.CrossRefGoogle Scholar
Piçarra, J. M., Štorch, P., Gutiérrez-Marco, J. C. & Oliveira, J. T. 1995. Characterization of the Parakidograptus acuminatus graptolite Biozone in the Silurian of the Barrancos region (Ossa Morena Zone, south Portugal). Comunicaçôes do Instituto Geológico e Mineiro 81, 3–8.Google Scholar
Podhalańska, T. 2003. Late Ordovician to Early Silurian transition and the graptolites from Ordovician/Silurian boundary near the SW rim of the East European Craton (Northern Poland). In Proceedings of the 7th International Graptolite Conference and Field Meeting of the ISSS (eds Ortega, G., G. & Aceñolaza, G. F.), pp. 165–71. INSUGEO, Serie Correlación Geológica 18.Google Scholar
Puddu, C. & Casas, J. M. 2011. New insights into the stratigraphy and structure of the Upper Ordovician rocks of the La Cerdanya area (Pyrenees). In Ordovician of the World (eds Gutiérrez-Marco, J. C., Rábano, I. & García-Bellido, D. C.), pp. 441–5. IGME, Cuadernos del Museo Geominero 14.Google Scholar
Puddu, C., Casas, J. M. & Álvaro, J. J. 2017. On the Upper Ordovician of the La Cerdanya area, Pyrenees. Géologie de la France 2017 (1), 26–8.Google Scholar
Rickards, R. B. 1970. The Llandovery (Silurian) Graptolites of the Howgill Fells, Northern England. Palaeontographical Society, London, Monograph no. 123(524), 1–108.Google Scholar
Rickards, R. B. & Hutt, J. 1970. The earliest monograptid. Proceedings of the Geological Society of London 1663, 115–9.Google Scholar
Roqué, J. 1999. La Biozona ascensus–acuminatus en el Silúrico de las Cadenas Costeras Catalanas (NE de España). Temas Geológico-Mineros ITGE 26, 632–7.Google Scholar
Roqué Bernal, J., Štorch, P. & Gutiérrez-Marco, J. C. 2017. Bioestratigrafía (graptolitos) del límite Ordovícico–Silúrico en los Pirineos orientales (curso alto del río Segre, Lleida). Geogaceta 61, 27– 30.Google Scholar
Roussel, J. 1904. Tableau stratigraphique des Pyrénées. Bulletin de la Carte Géologique de la France 97, 1–141.Google Scholar
Sachanski, V. 1993. Boundaries of the Silurian System in Bulgaria defined by graptolites. Geologica Balcanica 23, 25–33.Google Scholar
Schauer, M. 1971. Biostratigraphie und Taxionomie der Graptolithen des tieferen Silurs unter besonderer Berucksichtigung der tektonischen Deformation. Freiberger Forschungshefte, Paläontologie C273, 1–185.Google Scholar
Schmidt, H. 1931. Das Paläozoikum des Spanischen Pyrenäen. Abhandlungen der Gessellschaft der Wissenschaften zu Göttingen, Mathematik-Physik Klasse 3 [H 5] 8, 981–1065.Google Scholar
Stein, V. 1965. Stratigraphische und paläontologische Untersuchungen im Silur des Frankenwaldes. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 121, 111–200.Google Scholar
Štorch, P. 1982. Ordovician–Silurian boundary in the northernmost part of the Prague Basin (Barrandian, Bohemia). Věstník Ústředního ústavu geologického 57, 231–6.Google Scholar
Štorch, P. 1983. The genus Diplograptus (Graptolithina) from the lower Silurian of Bohemia. Věstník Ústředního ústavu geologického 58, 159–70.Google Scholar
Štorch, P. 1985. Orthograptus s.l. and Cystograptus (Graptolithina) from the Bohemian lower Silurian. Věstník Ústředního ústavu geologického 60, 87–99.Google Scholar
Štorch, P. 1986. Ordovician–Silurian boundary in the Prague Basin (Barrandian area, Bohemia). Sborník geologických Věd, Geologie 41, 69–103.Google Scholar
Štorch, P. 1992. Some new and little known graptolites from the Lower Silurian of Bohemia (Prague Basin, Barrandian Area). Časopis pro Mineralogii a Geologii 37, 193–201.Google Scholar
Štorch, P. 1996. The basal Silurian Akidograptus ascensus–Parakidograptus acuminatus Biozone in peri-Gondwanan Europe: graptolite assemblages, stratigraphical ranges and palaeobiogeography. Bulletin of the Czech Geological Survey 71, 171–8.Google Scholar
Štorch, P. & Feist, R. 2008. Lowermost Silurian graptolites of Montagne Noire, France. Journal of Paleontology 82, 938–56.CrossRefGoogle Scholar
Štorch, P. & Loydell, D. K. 1996. The Hirnantian graptolites Normalograptus persculptus and “Glyptograptus bohemicus”: stratigraphical consequences of their synonymy. Palaeontology 39, 869–81.Google Scholar
Štorch, P. & Schönlaub, H.-P. 2012. Ordovician–Silurian boundary graptolites of the Southern Alps, Austria. Bulletin of Geosciences 87, 755–66.CrossRefGoogle Scholar
Štorch, P. & Serpagli, E. 1993. Lower Silurian graptolites from southwestern Sardinia. Bollettino della Società Paleontologica Italiana 32, 3–57.Google Scholar
Sun, Y. C. 1933. Ordovician and Silurian graptolites from China. Palaeontographica Sinica, B 14, 1–52.Google Scholar
Törnquist, S. L. 1897. On the Diplograptidae and Heteroprionidae of the Scanian Rastrites Beds. Lunds Universitets Årsskrifter 33, 1–24.Google Scholar
Torsvik, T. H. & Cocks, L. R. M. 2017. Earth History and Palaeogeography. Cambridge: Cambridge University Press, 317 pp.CrossRefGoogle Scholar
Trela, W., Podhałańska, T., Smolarek, J. & Marynowski, L. 2016. Llandovery green/grey and black mudrock facies of the northern Holy Cross Mountains (Poland) and their relation to early Silurian sea-level changes and benthic oxygen level. Sedimentary Geology 342, 66–77.CrossRefGoogle Scholar
Underwood, C. J., Crowley, S. F., Marshall, J. D. & Brenchley, P. J. 1997. High-resolution carbon isotope stratigraphy of the basal Silurian stratotype (Dob's Linn, Scotland) and its global correlation. Journal of the Geological Society of London 154, 709–18.CrossRefGoogle Scholar
Underwood, C. J., Deynoux, M. & Ghienne, J. F. 1998. High palaeolatitude (Hodh, Mauritania) recovery of graptolite faunas after the Hirnantian (end Ordovician) extinction event. Palaeogeography, Palaeoclimatology, Palaeoecology 142, 91–105.CrossRefGoogle Scholar
Vandenbroucke, T. R. A., Emsbo, P., Munnecke, A., Nuns, N., Duponchel, L., Lepot, K., Quijada, M., Paris, F., Servais, T. & Kiessling, W. 2015. Metal-induced malformations in early Palaeozoic plankton are harbingers of mass extinction. Nature Communications 6 (7966), 6 pp.CrossRefGoogle ScholarPubMed
Williams, S. H. 1983. The Ordovician-Silurian boundary graptolite fauna of Dob's Linn, southern Scotland. Palaeontology 26, 605–39.Google Scholar
Williams, M., Zalasiewicz, J., Boukhamsin, H. & Cesari, C. 2016. Early Silurian (Llandovery) graptolite assemblages of Saudi Arabia: biozonation, palaeoenvironmental significance and biogeography. Geological Quarterly 60, 3–25.CrossRefGoogle Scholar
Ye, S. H. 1978. Graptolithina. In Palaeontological Atlas of Southwest China, Sichuan Volume, Part 1, From Sinian to Devonian, pp. 431–86. Beijing: Geological Publishing House [in Chinese].Google Scholar