Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-17T22:23:55.189Z Has data issue: false hasContentIssue false
  • English
  • Français

Guzhangian (mid Cambrian) trilobites from siliceous concretions of the Valtorres Formation, Iberian Chains, NE Spain

Published online by Cambridge University Press:  19 July 2012

J. JAVIER ÁLVARO ,
SAMUEL ZAMORA ,
DANIEL VIZCAÏNO  and
PER AHLBERG
J. JAVIER ÁLVARO*
Affiliation:
Centre of Astrobiology (CSIC/INTA), Ctra. de Torrejón a Ajalvir km 4, 28850 Torrejón de Ardoz, Spain
SAMUEL ZAMORA
Affiliation:
Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
DANIEL VIZCAÏNO
Affiliation:
7 Jean-Baptiste Chardin, Maquens, 11090 Carcassonne, France
PER AHLBERG
Affiliation:
Division of Geology, Department of Earth and Ecosystem Sciences, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
*
†Author for correspondence: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

In the carbonate-siliciclastic strata of West Gondwana (e.g. in the Montagne Noire, France), the aftermath of the mid Languedocian (mid Cambrian) regression is characterized by a late Languedocian major turnover of trilobite families and a Furongian–early Tremadocian radiation related to the stepwise immigration of trilobite invaders from East Gondwana under persistent transgressive conditions. The scarcity of upper Languedocian fossil accumulations in clayey substrates has inspired the sampling of the palaeogeographically most distal parts of the Iberian Chains (Spain), where diagenetic dissolution of ubiquitous hexactinellid sponge spicules has favoured the formation of siliceous concretions. These have yielded the trilobites Peronopsis cf. insignis, Oidalagnostus trispinifer, Proampyx difformis (= Proampyx aculeatus), Bailiaspis? glabrata (= Holocephalina agrauloides, by ontogeny), Holasaphus cf. centropyge and a paradoxidid gen. et sp. indet. Despite preservation and sampling biases, the identification of this taphonomic window in offshore clayey substrates of West Gondwana allows the recognition of a strong biogeographical link with Baltica, and the correlation of the global Guzhangian Stage and the Solenopleura? brachymetopa Zone of Scandinavia with part of the Mediterranean upper Languedocian Substage.

Keywords

taphonomybiogeographyLanguedocianBalticaGondwana
Type
Original Articles
Information
Geological Magazine , Volume 150 , Issue 1 , January 2013 , pp. 123 - 142
Copyright
Copyright © Cambridge University Press 2012

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

Ahlberg, P. 1984. Lower Cambrian trilobites and biostratigraphy of Scandinavia. Lund Publications in Geology 22, 1–37.Google Scholar
Ahlberg, P., Axheimer, N., Babcock, L. E., Eriksson, M. E., Schmitz, B. & Terfelt, F. 2009. Cambrian high-resolution biostratigraphy and carbon isotope chemostratigraphy in Scania, Sweden: first record of the SPICE and DICE excursions in Scandinavia. Lethaia 42, 2–16.Google Scholar
Ahlberg, P. & Bergström, J. 1978. Lower Cambrian ptychopariid trilobites from Scandinavia. Sveriges Geologiska Undersökning Ca49, 1–41.Google Scholar
Álvaro, J. J. 2007. New ellipsocephalid trilobites from the lower Cambrian member of the Láncara Formation, Cantabrian Mountains, northern Spain. Memoirs of the Association of Australasian Palaeontologists 34, 29–41.Google Scholar
Álvaro, J. J., Bauluz, B., Pierre, C., Subías, I. & Vizcaïno, D. 2008 a. Carbon chemostratigraphy of the Cambrian–Ordovician transition in a midlatitude mixed platform, Montagne Noire, France. Geological Society of America Bulletin 120, 962–75.CrossRefGoogle Scholar
Álvaro, J. J., Elicki, O., Geyer, G., Rushton, A. W. A. & Shergold, J. H. 2003. Palaeogeographical controls on the Cambrian trilobite immigration and evolutionary patterns reported in the western Gondwana margin. Palaeogeography, Palaeoclimatology, Palaeoecology 195, 5–35.Google Scholar
Álvaro, J. J., Ezzouhairi, H., Ribeiro, M. L., Ramos, J. F. & Solá, A. R. 2008 b. Early Ordovician volcanism of the Iberian Chains (NE Spain) and its influence on preservation of shell concentrations. Bulletin de la Société géologique de France 179, 569–81.Google Scholar
Álvaro, J. J., Ferretti, F., González-Gómez, C., Serpagli, E., Tortello, M. F., Vecoli, M. & Vizcaïno, D. 2007. A review of the Late Cambrian (Furongian) palaeogeography in the western Mediterranean region, NW Gondwana. Earth-Science Reviews 85, 47–81.Google Scholar
Álvaro, J. J., González-Gómez, C. & Vizcaïno, D. 2003. Paleogeographic patterns of the Cambrian–Ordovician transition in the southern Montagne Noire (France): preliminary results. Bulletin de la Société géologique de France 174, 23–31.Google Scholar
Álvaro, J. J., Lefebvre, B., Shergold, J. H. & Vizcaïno, D. 2001. The Middle–Upper Cambrian of the southern Montagne Noire. Annales de la Société Géologique du Nord (2e série) 8, 205–11.Google Scholar
Álvaro, J. J., Monceret, E., Monceret, S., Verraes, G. & Vizcaïno, D. 2010. Stratigraphic record and palaeogeographic context of the Cambrian Epoch 2 subtropical carbonate platforms and their basinal counterparts in SW Europe, West Gondwana. Bulletin of Geosciences 85, 573–84.Google Scholar
Álvaro, J. J. & Vennin, E. 1997. Episodic development of Cambrian eocrinoid-sponge meadows in the Iberian Chains (NE Spain). Facies 37, 49–64.Google Scholar
Álvaro, J. J. & Vizcaïno, D. 1998. Révision biostratigraphique du Cambrien moyen du versant méridional de la Montagne Noire (Languedoc, France). Bulletin de la Société géologique de France 169, 233–42.Google Scholar
Álvaro, J. J. & Vizcaïno, D. 2003. The conocoryphid biofacies, a benthic assemblage of normal-eyed and blind trilobites. Special Papers in Palaeontology 70, 127–40.Google Scholar
Álvaro, J. J., Vizcaïno, D., Kordule, V., Fatka, O. & Pillola, G. L. 2004. Some solenopleurine trilobites from the Languedocian (late Mid Cambrian) of western Europe. Geobios 37, 135–47.Google Scholar
Álvaro, J. J., Vizcaïno, D. & Vennin, E. 1999. Trilobite diversity patterns in the Middle Cambrian of southwestern Europe: a comparative study. Palaeogeography, Palaeoclimatology, Palaeoecology 151, 241–54.Google Scholar
Angelin, N. P. 1851. Palaeontologia Svecica. Pars I: Iconographia Crustaceorum Formationis Transitionis. Fascicule I. Lund, 24 pp.Google Scholar
Angelin, N. P. 1854. Palaeontologia Scandinavica. Pars I: Crustacea Formationis Transitionis. Fascicule II. T. O. Weigel, Leipzig: Academiae Regiae Scientarium Suecanae, I–IX + 21–92.Google Scholar
Angelin, N. P. 1878. Palaeontologica Scandinavica. 1: Crustacea Formationis Transitionis. Fascicule 1 and 2. Holmiae (Stockholm): Samson & Wallin, 96 pp.Google Scholar
Axheimer, N. & Ahlberg, P. 2003. A core drilling through Cambrian strata at Almbacken, Scania, S. Sweden: trilobites and stratigraphical assessment. GFF 125, 139–56.Google Scholar
Axheimer, N., Eriksson, M. E., Ahlberg, P. & Bengtsson, A. 2006. The middle Cambrian cosmopolitan key species Lejopyge laevigata and its biozone: new data from Sweden. Geological Magazine 134, 446–55.Google Scholar
Babcock, L. E. 1994 a. Systematics and phylogenetics of polymeroid trilobites from the Henson Gletscher and Kap Stanton formations (Middle Cambrian), North Greenland. Grønlands Geologiske Undersøgelse Bulletin 169, 79–127.Google Scholar
Babcock, L. E. 1994 b. Biogeography and biofacies patterns of Middle Cambrian polymeroid trilobites from North Greenland: palaeogeographic and palaeo-oceanographic implications. Grønlands Geologiske Undersøgelse Bulletin 169, 129–47.Google Scholar
Berg-Madsen, V. 1985. A review of the Andrarum Limestone and the upper Alum Shale (Middle Cambrian) of Bornholm, Denmark. Bulletin of the Geological Society of Denmark 34, 133–43.CrossRefGoogle Scholar
Bergström, J. & Ahlberg, P. 1981. Uppermost Lower Cambrian biostratigraphy in Scania, Sweden. Geologiska Föreningens i Stockholm Förhandlingar 103, 193–214.Google Scholar
Beyrich, E. 1845. Über einige böhmische Trilobiten. Berlin: G. Reimer, 47 pp.Google Scholar
Cocks, L. R. M. & Fortey, R. A. 2009. Avalonia: a long-lived terrane in the Lower Palaeozoic? In Early Palaeozoic Peri-Gondwana Terranes: New Insights from Tectonics and Biogeography (ed. Bassett, M. G.), pp. 141–55. Geological Society, London, Special Publication no. 325.Google Scholar
Cotton, T. J. 2001. The phylogeny and systematics of blind Cambrian ptychoparioid trilobites. Palaeontology 44, 167–207.Google Scholar
Courtessole, R. 1973. Le Cambrien moyen de la Montagne Noire. Biostratigraphie. Toulouse: Imprimerie d'Oc, 248 pp.Google Scholar
Courtessole, R., Pillet, J. & Vizcaïno, D. 1988. Stratigraphie et paléontologie du Cambrien moyen gréseux de la Montagne Noire (versant méridional). Mémoire de la Société d'Etudes Scientifiques de l'Aude, 55 pp.Google Scholar
Dalman, J. W. 1828. Årsberättelse om nyare zoologiska arbeten och upptäckter, till Kongliga Vetenskaps-Academien afgifven den 31 mars 1828. Stockholm: P. A. Norstedt & Söner, 138 pp.Google Scholar
Dawson, J. W. 1868. Acadian Geology: The Geological Structure, Organic Remains and Mineral Resources of Nova Scotia, New Brunswick, and Prince Edward Island. London, 694 pp.Google Scholar
Dean, W. T. 1972. The trilobite genus Holasaphus Matthew, 1895 in the Middle Cambrian rocks of Nova Scotia and eastern Turkey. Canadian Journal of Earth Sciences 9, 266–79.Google Scholar
Dean, W. T. 1982. Middle Cambrian trilobites from the Sosink Formation, Derik-Mardin district, south-eastern Turkey. Bulletin of the British Museum (Natural History), Geology Series 36, 1–41.Google Scholar
Egorova, L. I., Shabanov, Y. Y., Pegel, T. V., Savitsky, V. E., Suchov, S. S. & Chernysheva, N. E. 1982. The Mayan Stage in the stratotype area (Middle Cambrian of the southeastern Siberian Platform). Academy of Sciences of the USSR, Ministry of Geology of the USSR, Interdepartmental Stratigraphic Committee of the USSR, Transactions 8, 1–146 (in Russian).Google Scholar
Feist, R. & Courtessole, R. 1984. Découverte du Cambrien supérieur à trilobites de type Est-asiatique dans la Montagne Noire (France méridionale). Comptes Rendus de l'Académie des Sciences, Paris 298, 177–82.Google Scholar
Fletcher, T. P. 2007. Correlating the zones of ‘Paradoxides hicksii’ and ‘Paradoxides davidis’ in Cambrian Series 3. Memoirs of the Association of Australasian Palaeontologists 33, 35–56.Google Scholar
Fletcher, T. P., Theokritoff, G., Lord, G. S. & Zeoli, G. 2005. The early paradoxidid harlani trilobite fauna of Massachusetts and its correlatives in Newfoundland, Morocco, and Spain. Journal of Paleontology 79, 312–36.2.0.CO;2>CrossRefGoogle Scholar
Fortey, R. A. 1990. Ontogeny, hypostome attachment and trilobite classification. Palaeontology 33, 529–76.Google Scholar
Frech, F. 1897. Lethaea Geognostica, Teil 1. Lethaea Palaeozoica 2, 1–256.Google Scholar
Geyer, G. 1990. Die marokkanischen Ellipsocephalidae (Trilobita: Redlichiida). Beringeria 3, 1–363.Google Scholar
Geyer, G. 1998. Intercontinental, trilobite-based correlation of the Moroccan early Middle Cambrian. Canadian Journal of Earth Sciences 35, 374–401.Google Scholar
Geyer, G. 2010. Cambrian and lowermost Ordovician of the Franconian Forest. In The 15th Field Conference of the Cambrian Stage Subdivision Working Group. International Subcommission on Cambrian Stratigraphy, 4–11 June 2010. Abstracts and Excursion Guide. Prague, Czech Republic and south-eastern Germany (eds Fatka, O. & Budil, P.), pp. 78–92. Prague: Czech Geological Survey.Google Scholar
Geyer, G. & Landing, E. 2001. Middle Cambrian of Avalonian Massachusetts: stratigraphy and correlation of the Braintree trilobites. Journal of Paleontology 75, 116–35.Google Scholar
Geyer, G. & Landing, E. 2004. A unified Lower–Middle Cambrian chronostratigraphy for West Gondwana. Acta Geologica Polonica 54, 233–73.Google Scholar
González-Gómez, C. 2005. Linguliformean brachiopods of the Middle–Upper Cambrian transition from the Val d'Homs Formation, southern Montagne Noire, France. Journal of Paleontology 79, 29–47.Google Scholar
Gozalo, R. & Liñán, E. 1996. Nueva especie de Conocoryphidae (Trilobita), Cámbrico Medio de las Cadenas Ibéricas (NE de España). Revista Española de Paleontología 11, 247–50.Google Scholar
Grönwall, K. A. 1902. Bornholms Paradoxideslag og deres Fauna. Danmarks Geologiske Undersøgelse 2 (13), 1–230.Google Scholar
Harrington, H. J., Henningsmoen, G., Howell, B. F., Jaanusson, V., Lochman-Balk, C., Moore, R. C., Poulsen, C., Rasetti, F., Richter, E., Richter, R., Schmidt, H., Sdzuy, K., Struve, W., Tripp, R., Weller, J. M. & Whittington, H. B. 1959. Systematic descriptions. In Treatise on Invertebrate Paleontology, Part O. Arthropoda 1 (ed. Moore, R. C.), pp. 170–539. Boulder and Lawrence: Geological Society of America and University of Kansas Press.Google Scholar
Hawle, I. & Corda, A. J. C. 1847. Prodrom einer Monographie der böhmischen Trilobiten. Königliche Böhmische Gessellschaft der Wissenschaften, Abhandlungen 5, 1–176.Google Scholar
Hicks, H. 1872. On some undescribed fossils from the Menevian Group. Quarterly Journal of the Geological Society of London 28, 173–85.Google Scholar
Hupé, P. 1953. Contribution à l’étude du Cambrien inférieur et du Précambrien III de l'Anti-Atlas marocain. Notes et Mémoires du Service Géologique du Maroc 103, 1–402.Google Scholar
Hutchinson, R. D. 1962. Cambrian stratigraphy and trilobite faunas in southeast Newfoundland. Geological Survey of Canada Bulletin 88, 1–156.Google Scholar
Illing, V. C. 1916. The Paradoxidian fauna of a part of the Stockingford Shales. Quarterly Journal of the Geological Society of London 71, 386–448.Google Scholar
Josopait, V. 1972. Das Kambrium und das Tremadoc von Ateca (Westliche Iberischen Ketten, NE-Spanien). Münstersche Forschungen zur Geologie und Paläontologie 23, 1–121.Google Scholar
Kim, D. H., Westrop, S. R. & Landing, E. 2002. Middle Cambrian (Acadian Series) conocoryphid and paradoxidid trilobites from the Upper Chamberlain's Brook Formation, Newfoundland and New Brunswick. Journal of Paleontology 76, 822–42.Google Scholar
Korobov, M. N. 1966. New trilobites of the family Conocoryphidae from the Cambrian of the Siberian Platform and Tuva. Paleontologicheskiy Zhurnal 1966, 92–7 (in Russian).Google Scholar
Korobov, M. N. 1973. Trilobites of the family Conocoryphidae and their significance for Cambrian stratigraphy. Trudy Geologicheskovo Instituta, Akademija Nauk SSSR 211, 1–176 (in Russian).Google Scholar
Kouchinsky, A., Bengtson, S., Gallet, Y., Korovnikov, I., Pavlov, V., Runnegar, B., Shields, G., Veizer, J., Young, E. & Ziegler, K. 2008. The SPICE carbon isotope excursion in Siberia: a combined study of the upper Middle Cambrian–lowermost Ordovician Kulyumbe River section, northwestern Siberian Platform. Geological Magazine 145, 609–22.CrossRefGoogle Scholar
Lake, P. 1906–1946. The Cambrian Trilobites, Parts 1–14. London: Monograph of the Palaeontographical Society, 350 pp.Google Scholar
Loi, A. & Dabard, M. P. 2002. Controls of sea level fluctuations on the formation of Ordovician siliceous nodules in terrigenous offshore environments. Sedimentary Geology 153, 65–84.Google Scholar
Matthew, G. F. 1885. Illustrations of the fauna of the St. John Group continued: On the Conocoryphaea, with further remarks on Paradoxides. Proceedings and Transactions of the Royal Society of Canada 2 (4), 99–124.Google Scholar
Matthew, G. F. 1886. Illustrations of the fauna of the St. John Group continued. No. III: Descriptions of new genera and species (including a description of a new species of Selenopleura by J. F. Whiteaves). Proceedings and Transactions of the Royal Society of Canada 3 (4), 29–84.Google Scholar
Matthew, G. F. 1887. Illustrations of the fauna of the St. John Group. No. 4: On the smaller-eyed trilobites of Division I, with a few regards on the species of the higher divisions of the group. Canadian Record of Science 2, 357–63.Google Scholar
Matthew, G. F. 1891. Illustrations of the fauna of the St. John Group. No. 5. Proceedings and Transactions of the Royal Society of Canada 8 (4), 123–66.Google Scholar
Matthew, G. F. 1895. Traces of the Ordovician System on the Atlantic coast. Proceedings and Transactions of the Royal Society of Canada, 2nd Series 1 (4), 253–71.Google Scholar
Matthew, G. F. 1899. Studies on Cambrian faunas, No. 4. Fragments of the Cambrian Faunas of Newfoundland. Proceedings and Transactions of the Royal Society of Canada, 2nd Series 5 (4), 67–95.Google Scholar
Miquel, J. 1905. Essai sur le Cambrien de la Montagne Noire. Coulouma – L'Acadien. Bulletin de la Société géologique de France (4e série) 5, 465–83.Google Scholar
Öpik, A. A. 1967. The Mindyallan fauna of north-western Queensland. Commonwealth of Australia, Bureau of Mineral Resources, Geology and Geophysics Bulletin 74, 1–404.Google Scholar
Pearson, K. 1900. On the criterion that a given system of deviations from the probable in the case of a correlated system of variables is such that it can be reasonably supposed to have arisen from random sampling. Philosophical Magazine, Series 5 50 (302), 157–75.Google Scholar
Peng, S. C., Babcock, L. E., Zuo, J. X., Lin, H. L., Zhu, X. J., Yang, X. F., Robison, R. A., Qi, Y. P., Bagnoli, G. & Chen, Y. 2006. Proposed GSSP for the base of Cambrian Stage 7, coinciding with the first appearance of Lejopyge laevigata, Hunan, China. Palaeoworld 15, 367–83.Google Scholar
Peng, S. C., Babcock, L. E., Zuo, J. X., Lin, H. L., Zhu, X. J., Yang, X. F., Robison, R. A., Qi, Y. P., Bagnoli, G. & Chen, Y. 2009. The Global Boundary Stratotype Section and Point (GSSP) of the Guzhangian Stage (Cambrian) in the Wuling Mountains, northwestern Hunan, China. Episodes 32, 41–55.Google Scholar
Peng, S. C. & Robison, R. A. 2000. Agnostoid biostratigraphy across the Middle–Upper Cambrian boundary in Hunan, China. Memoirs of the Paleontological Society 53, 1–104.Google Scholar
Poulsen, C. 1959. Family Conocoryphidae. In Treatise on Invertebrate Paleontology, Pt. O, Arthropoda 1 (ed. Moore, R. C.), pp. O242–O244. Boulder and Lawrence: Geological Society of America and University of Kansas Press.Google Scholar
Raymond, P. E. 1913. Revision of the species which have been referred to the genus Bathyurus. Bulletin of the Victoria Memorial Museum 1, 51–69.Google Scholar
Repina, L. N., Petrunina, Z. E. & Hajrullina, T. I. 1975. Trilobites. In Stratigraphy and Fauna of the Lower Paleozoic of the Northern Submontane Belt of Turkestan and Alai Ridges (southern Tyan-shan) (eds Repina, L. N., Yaskovich, B. V., Aksarina, N. A., Petrunina, Z. E., Poniklenko, I. A., Rubanov, D. A., Bolgova, G. V., Golikov, A. N., Hajrullina, T. I. & Posokhova, M. M.). Akademiya Nauk SSSR, Sibirskoe Otdelenie, Instituta Geologii i Geofiziki, Trudy 278, 100–248 (in Russian).Google Scholar
Resser, C. E. 1936. Second contribution to nomenclature of Cambrian trilobites. Smithsonian Miscellaneous Collections 95 (4), 1–29.Google Scholar
Resser, C. E. 1937. New species of Cambrian trilobites of the family Conocoryphidae. Journal of Paleontology 11, 39–42.Google Scholar
Robison, R. A. 1988. Trilobites of the Holm Dal Formation (late Middle Cambrian), central North Greenland. Meddelelser om Grønland, Geoscience 20, 23–103.Google Scholar
Robison, R. A. 1994. Agnostoid trilobites from the Henson Gletscher and Kap Stanton formations (Middle Cambrian), North Greenland. Grønlands Geologiske Undersøgelse Bulletin 169, 25–77.Google Scholar
Rouville, de P. G., Delage, A. & Miquel, J. 1894. Les Terrains Primaires de l'Arrondissement de Saint-Pons (Hérault). Montpellier: Typographie et Lithographie Charles Boehm, 46 pp.Google Scholar
Rudolph, F. 1994. Die Trilobiten der mittelkambrischen Geschiebe. Systematik, Morphologie und Ökologie. Wankendorf: Verlag Frank Rudolph, 309 pp.Google Scholar
Růžička, R. 1946. O některých význačných trilobitech skrýjského kambria. Věstník Královské české společnosti nauk, Třida matematicko-přírodovědecká (for 1944), 1–26.Google Scholar
Salter, J. W. 1864. On some new fossils from the Lingula-flags of Wales. Quarterly Journal of the Geological Society of London 20, 233–41CrossRefGoogle Scholar
Schmitz, U. 1971. Stratigraphie und sedimentologie im Kambrium und Tremadoc der Westlichen Iberischen Ketten nördlich Ateca (Zaragoza), NE-Spanien. Münstersche Forschungen zur Geologie und Paläontologie 22, 1–123.Google Scholar
Sdzuy, K. 1958. Neue Trilobiten aus dem Mittelkambrium von Spanien. Senckenbergiana Lethaea 39, 235–53.Google Scholar
Sdzuy, K. 1961. Das Kambrium Spaniens. Teil II: Trilobiten, 1. Akademie der Wissenschaften und der Literatur in Mainz, Abhandlungen der Mathematisch-Naturwissenschaftlichen Klasse 7, 499–594.Google Scholar
Sdzuy, K. 1966. Das Kambrium des Frankenwaldes. 2, Die Bergleshof-Schichten und ihre Trilobiten-Fauna. Senckenbergiana Lethaea 47, 57–86.Google Scholar
Sdzuy, K. 1968. Trilobites del Cámbrico Medio de Asturias. Trabajos de Geología, Universidad de Oviedo 1, 77–133.Google Scholar
Sdzuy, K. 1971. Acerca de la correlación del Cámbrico inferior de la Península Ibérica. I Congreso Hispano-Luso-Americano de Geología Económica, Sección 1 (Geología) 2, 753–68.Google Scholar
Sdzuy, K. 1972. Das Kambrium der Acadobaltischen Faunenprovinz – Gegenwärtiger Kenntnisstand und Probleme. Zentralblatt für Geologie und Paläontologie (II) 1972, 1–91.Google Scholar
Sdzuy, K. & Liñán, E. 1996. Cornucoryphe schirmi n. gen. n. sp., an unusual conocoryphid trilobite from the Middle Cambrian of Spain. Paläontologische Zeitschrift 70, 433–8.Google Scholar
Shergold, J. H., Feist, R. & Vizcaïno, D. 2000. Early Late Cambrian trilobites of Australo-Sinian aspect from the Montagne Noire, southern France. Palaeontology 43, 599–632.Google Scholar
Shergold, J. H. & Sdzuy, K. 1991. Late Cambrian trilobites from the Iberian Mountains, Zaragoza Province, Spain. Beringeria 4, 193–235.Google Scholar
Šnajdr, M. 1958. Trilobiti českého středního kambria. Rozpravi Ústředního Ústavu Geologického 24, 1–280.Google Scholar
St John, J. M. & Babcock, L. E. 1997. Late Middle Cambrian trilobites of Siberian aspect from the Farewell terrane, southwestern Alaska. In Geologic Studies in Alaska (eds Dumoulin, J. A. & Gray, J. F.), pp. 269–81. US Geological Survey, Professional Paper no. 1574.Google Scholar
Stubblefield, C. J. 1951. New names for the trilobite genera Menevia Lake and Psilocephalus Salter. Geological Magazine 88, 213–4.Google Scholar
Thoral, M. 1946. Conocoryphidae languedociens. Annales de l'Université de Lyon, 3ème Série, Section C, Sciences Naturelles 4, 5–74.Google Scholar
Vizcaïno, D. & Álvaro, J. J. 2003. Adequacy of the Lower Ordovician trilobite record in the southern Montagne Noire (France): biases for biodiversity documentation. Transactions of the Royal Society of Edinburgh: Earth Sciences 93, 1–9.Google Scholar
Wallerius, I. D. 1895. Undersökningar öfver zonen med Agnostus laevigatus i Vestergötland, jämte en inledande öfversikt af Vestergötlands samtliga Paradoxideslager. Lund: Gleerupska Universitetsbokhandeln, 72 pp. (in Swedish).Google Scholar
Warnke, K. 1995. Calcification processes of siliceous sponges in Viséan Limestones (Counties Sligo and Leitrim, Northwestern Ireland). Facies 33, 215–28.Google Scholar
Westergård, A. H. 1936. Paradoxides oelandicus beds of Öland with the account of a diamond boring through the Cambrian at Mossberga. Sveriges Geologiska Undersökning C394, 1–66.Google Scholar
Westergård, A. H. 1946. Agnostidea of the Middle Cambrian of Sweden. Sveriges Geologiska Undersökning C477, 1–140.Google Scholar
Westergård, A. H. 1950. Non-agnostidean trilobites of the Middle Cambrian of Sweden. II. Sveriges Geologiska Undersökning C511, 1–57.Google Scholar
Westergård, A. H. 1953. Non-agnostidean trilobites of the Middle Cambrian of Sweden. III. Sveriges Geologiska Undersökning C526, 1–59.Google Scholar
Whitehouse, F. W. 1936. The Cambrian faunas of north-eastern Australia. Part 1: stratigraphical outline; Part 2: Trilobita (Miomera). Memoirs of the Queensland Museum 11 (3), 179–282.Google Scholar
Whittington, H. B., Chatterton, B. D. E., Speyer, S. E., Fortey, R. A., Owens, R. M., Chang, W. T., Dean, W. T., Jell, P. A., Laurie, J. R., Palmer, A. R., Repina, L. N., Rushton, A. W. A., Shergold, J. H., Clarkson, E. N. K., Wilmot, N. V. & Kelly, S. R. A. 1997. Introduction, Order Agnostina, Order Redlichiida. In Treatise on Invertebrate Paleontology, Part O, Arthropoda 1, Trilobita, Revised, Volume 1 (ed. Kaesler, R. L.), pp. xxiv + 530. Boulder and Lawrence: Geological Society of America and University of Kansas Press.Google Scholar
Wotte, T., Álvaro, J. J., Shields, G. A., Brasier, M. & Veizer, J. 2007. C-, O- and Sr-isotope stratigraphy across the Lower–Middle Cambrian transition of the Cantabrian Mountains (Spain) and the Montagne Noire (France), West Gondwana. Palaeogeography, Palaeoclimatology, Palaeoecology 256, 47–70.Google Scholar
Young, T., Martin, F., Dean, W. T. & Rushton, A. W. A. 1994. Cambrian stratigraphy of St Tudwal's Peninsula, Gwynedd, northwest Wales. Geological Magazine 131, 335–60.Google Scholar
Zamora, S. 2010. Middle Cambrian echinoderms from north Spain show echinoderms diversified earlier in Gondwana. Geology 38, 507–10.Google Scholar
Zamora, S. & Álvaro, J. J. 2010. Testing for a decline in diversity prior to extinction: Languedocian (latest mid–Cambrian) distribution of cinctans (Echinodermata) in the Iberian Chains, NE Spain. Palaeontology 53, 1349–68.Google Scholar
Zhang, W. T. & Jell, P. A. 1987. Cambrian Trilobites of North China. Beijing: Science Press, 332 pp.Google Scholar
Zhou, Z. Q., Li, J. S. & Qu, X. G. 1982. Trilobita. In Palaeontological Atlas of Northwest China, Shanxi-Gansu-Ningxia Volume. Part 1: Precambrian and Early Palaeozoic, pp. 57–72. Beijing: Geological Publishing House.Google Scholar