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The oldest Cambrian skeletal fossils of Spain (Cadenas Ibéricas, Aragón)



Diverse skeletal assemblage has been discovered in the Ediacaran/Cambrian strata of the Codos locality in NE Spain (Aragón, Cadenas Ibéricas). This assemblage includes at least seven genera, only three of which can be ascribed to known taxa. All the fossils are preserved in phosphate but their original microstructures are traceable by both elementary composition and microstructural features that are indicative for primary aragonite and high-magnesium calcite biomineralogies. Already these early skeletal fossils show sophisticated microstructures represented by heterogeneous multilayered composites to satisfy the requirements for better protection against both chemical dissolution and mechanical predator deterioration. The most common and best-preserved fossil, which is tubicolous Codositubulus grioensis gen. et sp. nov., is described here. The composition of the fossil assemblage and its stratigraphic position are indicative for the lowermost Terreneuvian (lower Cambrian) or even pre-Terreneuvian age of this fauna.


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Álvaro, J. J., Bauloz, B., Gil Imaz, A. & Simón, J. L. 2008. Multidisciplinary constraints on the Cadomian compression and early Cambrian extension in the Iberian Chains, NE Spain. Tectonophysics 461, 215–27.
Álvaro, J. J. & Blanc-Valleron, M.-M. 2002. Stratigraphic and structural framework of the Neoproterozoic Paracuellos Group, Iberian Chains, NE Spain. Bulletin de la Société Géologique de France 173, 219–27.
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.
Álvaro, J. J., Shields-Zhou, G. A., Ahlberg, P., Jensen, S. & Palacios, T. 2015. Ediacaran-Cambrian phosphorites from the western margins of Gondwana and Baltica. Sedimentology 63, 350–77.
Bengtson, S., Conway Morris, S., Cooper, B. J., Jell, P. A. & Runnegar, B. N. 1990. Early Cambrian Fossils from South Australia. Memoir of the Association of Australasian Palaeontologists 9, 1364.
Billings, E. 1871. On some new species of Palaeozoic fossils. Canadian Naturalist 6, 213–23, 240.
Brasier, M. D. & Callow, R. H. T. 2007. Changes in the pattern of phosphatic preservation across the Proterozoic–Cambrian transition. Memoirs of the Association of Australasian Palaeontologists 34, 377–89.
Bruet, B. J. F., Qi, H. J., Boyce, M. C., Panas, R., Tai, K., Frick, L. & Ortiz, C. 2005. Nanoscale morphology and indentation of individual nacre tablets from the gastropod mollusk. Trochus niloticus. Journal of Materials Research 20, 2400–19.
Bruet, B. J. F., Song, J., Boyce, M. C. & Ortiz, C. 2008. Material design principles of ancient fish armour. Nature Materials 7, 748–56.
Budd, G. E. & Jackson, I. S. C. 2016. Ecological innovations in the Cambrian and the origins of the crown group phyla. Philosophical Transactions of the Royal Society B 371 (1685), 20150287. DOI: 10.1098/rstb.2015.0287
Cai, Y. P., Schiffbauer, J. C., Hua, H. & Xiao, S. 2011. Morphology and paleoecology of the late Ediacaran tubular fossil Conotubus hemiannulatus from the Gaojiashan Lagerstätte of southern Shaanxi Province, South China. Precambrian Research 191, 4657.
Chen, Z., Bengtson, S., Zhou, C.-M., Hua, H. & Yue, Z. 2008. Tube structure and original composition of Sinotubulites: shelly fossils from the late Neoproterozoic in southern Shaanxi, China. Lethaia 41, 3745.
Chen, M., Chen, Y. & Qian, Y. 1981. Some tubular fossils from Sinian–Lower Cambrian boundary sequences, Yangtze Gorge. Bulletin of Tianjiin Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences 3, 117–24 (in Chinese with English summary).
Cobbold, E. S. 1935. Lower Cambrian faunas from the Hérault, France. Annals and Magazine of Natural History, series 10 16, 2548.
Connors, M. J., Ehrlich, H., Hog, M., Godeffroy, C., Araya, S., Kallai, I., Gazit, D., Boyce, M. & Ortiz, C. 2012. Three-dimensional structure of the shell plate assembly of the chiton Tonicella marmorea and its biomechanical consequences. Journal of Structural Biology 177, 314–28.
Cook, P. J. & Shergold, J. H. 1984. Phosphorus, phosphorites and skeletal evolution at the Precambrian–Cambrian boundary. Nature 308 231–6.
Cortijo, I., Martí Mus, M., Jensen, S. & Palacios, T. 2010. A new species of Cloudina from the terminal Ediacaran of Spain. Precambrian Research 176, 110.
Cortijo, I., Martí Mus, M., Jensen, S. & Palacios, T. 2015. Late Ediacaran skeletal body fossil assemblage from the Navalpino anticline, central Spain. Precambrian Research 267, 186–95.
Devaere, L., Clausen, S., Steiner, M., Álvaro, J. J. & Vachard, D. 2013. Chronostratigraphic and palaeogeographic significance of an early Cambrian microfauna from the Heraultia Limestone, northern Montagne Noire, France. Palaeontologia Electronica 16 (2), 17A, 191.
Devaere, L., Holmer, L., Clausen, S. & Vachard, D. 2015. Oldest mickwitziid brachiopod from the Terreneuvian of southern France. Acta Palaeontologica Polonica 60, 755–68.
Ding, L.-F., Zhang, L., Li, Y. & Dong, J. 1992. The Study of the Late Sinian–Early Cambrian Biotas from the Northern Margin of Yangtze Platform. Beijing: Scientific and Technical Documents Publishing House: 135pp. (in Chinese with English summary).
Esakova, N. V. & Zhegallo, E. A. 1996. The Lower Cambrian biostratigraphy and fauna of Mongolia. Trudy Sovmestnoy Rossiysko-Mongol'skoy Paleontologicheskoy Ekspeditsii 46, 1216 (in Russian).
Fedorov, A. B. 1986. New tubicolous problematics from the Tommotian Stage stratotype. Paleontologicheskii Zhurnal 1986 (2), 110–11 (in Russian).
Fernández-Remolar, D. C. 2001. Latest Neoproterozoic to Middle Cambrian body fossil record in Spain (exclusive of trilobites and archaeocyaths) and their stratigraphic significance. Geologiska Föreningens i Stockholm Förhandlingar 123, 7380.
Fernández-Remolar, D. C. 2002. First record of Tannuolina Fonin & Smirnova, 1967 (Tommotiida) from the Lower Cambrian Pedroche Formation, southern Spain. Revista Española de Micropaleontolgía 34, 3951.
Fernández-Remolar, D. C. 2005. Primer registro de los géneros Actinotheca Xiao y Zou, 1984, y Conotheca Missarzhevsky, 1969, en el Cámbrico inferior de la Península Ibérica. In VIII Jornadas Aragonesas de Paleontología “La cooperación internacional en la Paleontología española”, Homenaje al Prof. Peter Carls. (eds Vintaned, J. A. Gámez, Liñán, E. & Valenzuela-Ríos, J. I.), pp. 7188. Zaragoza: Institución Fernando el Católico.
Fernández-Remolar, D. C., García-Hidalgo, J. F. & Moreno-Eiris, E. 2005. Interés del registro de los primeros organismos en el Arcaico y Proterozoico. Boletín de la Real Sociedad Española de Historia Natural (Sección Geológica) 100, 177209.
Gámez Vintaned, J. A., Schmitz, U. & Liñán, E. 2009. Upper Vendian–lowest Ordovician sequence of the western Gondwana margin, NE Spain. In Global Neoproterozoic Petroleum Systems: The Emerging Potential in North Africa (eds Craig, J., Thurow, J., Thusu, B., Whitham, A. & Abutarruma, Y.), pp. 231–44. Geological Society of London, Special Publication no. 326.
Grigorieva, N. V. & Zhegallo, E. A. 1979. To the study of the microstructure of some Tommotian fossils. Paleontologicheskii Zhurnal 1979 (2), 142–4 (in Russian).
Gubanov, A. P., Fernández-Remolar, D. C. & Peel, J. S. 2004. Early Cambrian molluscs from Sierra de Córdoba (Spain). Geobios 37, 199215.
Hall, J. 1879. New York State Geological Survey, Palaeontology of New York. Vol. 5 (2). Containing descriptions of Gasteropoda, Pteropoda and Cephalopoda of the Upper Helderberg, Hamilton, Portage, and Chemung groups. Albany, NY: C. van Benthuysen & Sons. Text volume, 492 pp.; plate volume, 113 pl.
Holm, G. 1893. Sveriges kambrisk–siluriska Hyolithidae och Conulariidae. Sveriges Geologiska Undersökning, Avhandlinger och Uppsatser C 112, 1172.
Jensen, S., Palacios, T. & Martí Mus, M. 2007. A brief review of the fossil record of the Ediacaran–Cambrian transition in the area of Montes de Toledo–Guadalupe, Spain. In The Rise and Fall of the Ediacaran Biota (eds Vickers-Rich, P. & Komarower, P.), pp. 223–35. Geological Society of London, Special Publication no. 286.
Jensen, S., Palacios, T. & Martí Mus, M. 2010. Revised biochronology of the Lower Cambrian of the Central Iberian zone, southern Iberian massif, Spain. Geological Magazine 147, 690703.
Kerber, M. 1988. Mikrofossilien aus unterkambrischen Gesteinen der Montagne Noire, Frankreich. Palaeontographica, Abteilung A 202, 127303.
Kobayashi, I. & Samata, T. 2006. Bivalve shell structure and organic matrix. Materials Science and Engineering C 26, 692–8.
Kouchinsky, A. 2000. Shell microstructure in Early Cambrian molluscs. Acta Palaeontologica Polonica 45, 119–50.
Li, X., Xu, Z.-H. & Wang, R. 2006. In situ observations of nanograin rotation and deformation in nacre. Nano Letters 6, 2301–4.
Liñán Guijarro, E. 1978. Bioestratigrafía de la Sierra de Córdoba. Tesis Doctorales de la Universidad de Granada, no. 191. Granada: Secretariado de Publicaciones de la Universidad de Granada, 212 pp.
Liñán, E., Gozalo, R., Palacios, T., Gámez Vintaned, J. A., Ugidos, J. M. & Mayoral, E. 2002. Cambrian. In The Geology of Spain (eds Gibbons, W. & Moreno, T.), pp. 1729. London: The Geological Society.
Liñán, E., Grant, S. & Navarro Vázquez, D. 1994. El Precámbrico de Codos (Zaragoza). Cadena Ibérica oriental. In XVI Reunión de Xeoloxía e Minería de N. O. Peninsular, “Evolución Quaternaria do Macizo Hespérico Peninsular”, O Castro, 23 ao 26 de Santos 1994, Resúmenes, p. 3.
Liñán, E., Palacios, T. & Perejón, A. 1984. Precambrian–Cambrian boundary and correlation from southwestern and central part of Spain. Geological Magazine 121, 221–8.
Liñán, E., & Tejero, R. 1988. Las formaciones precámbricas del antiforme de Paracuellos (Cadenas Ibéricas). Boletín de la Real Sociedad Española de Historia Natural (Sección Geológica) 84, 3949.
Missarzhevsky, V. V. & Mambetov, A. M. 1981. Stratigraphy and fauna of the Cambrian and Precambrian boundary beds in Maly Karatau. Trudy Geologichesko Instituta Akademii nauk SSSR 326, 192 (in Russian).
Nagovitsin, K. E., Rogov, V. I., Marusin, V. V., Karlova, G. A., Kolesnikov, A. V., Bykova, N. V. & Grazhdankin, D. V. 2015. Revised Neoproterozoic and Terreneuvian stratigraphy of the Lena-Anabar Basin and north-western slope of the Olenek Uplift, Siberian Platform. Precambrian Research 270, 226–45.
Palacios Medrano, T. 1989. Microfosiles de pared orgánica del Proterozoico Superior (región central de la Península Ibérica). Memorias del Museo Paleontológico de la Universidad de Zaragoza 3 (2), 191.
Parkhaev, P. Yu. 2006. On the genus Auricullina Vassiljeva, 1998 and shell pores of the Cambrian helcionelloid mollusks. Paleontological Journal 40, 2033.
Porter, S. M. 2004a. Halkieriids in Middle Cambrian phosphatic limestones from Australia. Journal of Paleontology 78, 574–90.
Porter, S. M. 2004b. Closing the phosphatization window: testing for the influence of taphonomic megabias on the pattern of small shelly fossil decline. Palaios 19, 178–83.
Poulsen, C. 1967. Fossils from the Lower Cambrian of Bornholm. Danske Videnskabernes Selskab, Matematisk-Fysiske Meddeleser 36, 148.
Pyle, L. J., Narbonne, G. M., Nowlan, G. S., Xiao, S. & James, N. P. 2006. Early Cambrian metazoan eggs, embryos, and phosphatic microfossils from northwestern Canada. Journal of Paleontology 80, 811–25.
Rodríguez Alonso, M. D, Alonso Gavilán, G., Liñán, E., Gámez Vintaned, J. A. & Pérez Garsía, P. P. 1995. Transversal Salamanca–Tamames–Peña de Francia-Monsagro–S Cuidad Rodrigo (Spain). In XIII Geological Meeting on the West of the Iberian Peninsula: Characterization and Evolution of the Neoproterozoic–Cambrian Basin on the Iberian Peninsula. Post-Conference Field Guide, September, 27–30th, 1995 (eds Rodríguez Alonso, M. D. & Alonso Gavilán, G.), pp. 13120. Salamanca: Universidad de Salamanca; Coimbra: Universidade de Coimbra.
Rogov, V. I., Karlova, G. A., Marusin, V. V., Kochnev, B. B., Nagovitsin, K. E. & Grazhdankin, D. V. 2015. Duration of the first biozone in the Siberian hypostratotype of the Vendian. Russian Geology and Geophysics 56, 573–83.
Rozanov, A. YU. & Missarzhevsky, V. V. 1966. Biostratigraphy and fauna of the Cambrian lower horizons. Trudy Geologichesko Instituta Akademii Nauk SSSR 148, 1120 (in Russian).
Rozanov, A. YU., Missarzhevsky, V. V., Volkova, N. A., Voronova, L. G., Krylov, I. N., Keller, B. M., Korolyuk, I. K., Lendzion, K., Michniak, R., Pykhova, N. G. & Sidorov, A. D. 1969. The Tommotian Stage and the Cambrian lower boundary problem. Trudy Geologichesko Instituta Akademii Nauk SSSR 206, 1380 (in Russian).
Rozanov, A. Yu., Parkhaev, P. Yu., Demidenko, Yu. E., Karlova, G. A., Korovnikov, I. V., Shabanov, Yu. Ya., Ivantsov, A. Yu., Luchinina, V. A., Malakhovskaya, Ya. E., Melnikova, L. M., Naimark, E. B., Ponomarenko, A. G., Skorlotova, N. A., Sundukov, V. M., Tokarev, D. A., Ushatinskaya, G. T. & Kipriyanova, L. K. 2010. Fossils from the Lower Cambrian Stage Stratotypes. Moscow: PIN RAN, 228 pp. (in Russian).
Shimura, T., Kon, Y., Sawaki, Y., Hirata, T., Han, J., Shu, D. & Komiya, T. 2014. In-situ analyses of phosphorus contents of carbonate minerals: reconstruction of phosphorus contents of seawater from the Ediacaran to early Cambrian. Gondwana Research 25, 1090– 107.
Skovsted, C. B. & Peel, J. S. 2011. Hyolithellus in life position from the Lower Cambrian of North Greenland. Journal of Paleontology 85, 3747.
Song, J., Ortiz, C. & Boyce, M. C. 2011. Threat-protection mechanics of an armored fish. Journal of Mechanical Behavior of Biomedical Materials 4, 699712.
Tai, K., Dao, M., Suresh, S., Palazoglu, A. & Ortiz, C. 2007. Nanoscale heterogeneity promotes energy dissipation in bone. Nature Materials 6, 454–62.
Taylor, P. D. & Weedon, M. J. 2000. Skeletal ultrastructure and phylogeny of cyclostome bryozoans. Zoological Journal of the Linnean Society 128, 337–99.
Vendrasco, M. J. & Checa, A. G. 2015. Shell microstructures and its inheritance in the calcitic helcionellid Mackinnonia. Estonian Journal of Earth Sciences 64, 99104.
Vendrasco, M. J., Porter, S. M., Kouchinsky, A., Li, G. & Fernandez, C. Z. 2010. New data on molluscs and their shell microstructures from the middle Cambrian Gowers Formation, Australia. Palaeontology 53, 97135.
Vidal, G., Palacios, T., Gámez-Vintaned, J. A., Díez Balda, M. A. & Grant, S. W. F. 1994. Neoproterozoic–early Cambrian geology and palaeontology of Iberia. Geological Magazine 131, 729–65.
Vidal, G., Palacios, T., Moczydłowska, M. & Gubanov, A. P. 1999. Age constraints from small shelly fossils on the early Cambrian terminal Cadomian Phase in Iberia. Geologiska Föreningens i Stockholm Förhandlingar 121, 137–43.
Vinn, O. 2006. Possible cnidarian affinities of Torellella (Hyolithelminthes, Upper Cambrian, Estonia). Paläontologische Zeitschrift 80, 384–9.
Vinn, O. & Zatoń, M. 2012. Phenetic phylogenetics of tentaculitoids – extinct, problematic calcareous tube-forming organisms. Scandinavian Journal of Earth Sciences 134, 145–56.
Williams, A., Cusack, M. & Brown, K. 1999. Growth of protein-doped rhombohedra in the calcitic shell of craniid brachiopods. Proceedings of the Royal Society of London B 266, 1601–7.
Yang, B., Steiner, M., Zhu, M., Li, G., Liu, J. & Liu, P. 2016. Transitional Ediacaran-Cambrian small skeletal fossil assemblages from South China and Kazakhstan: implications for chronostratigraphy and Metazoan evolution. Precambrian Research 285, 202–15.
Yin, J., Ding, L., He, T., Li, S. & Shen, L. 1980. Palaeontology and Sedimentary Environment of the Sinian System in Emei-Ganluo Area. Chengdu: Sichuan People's Publishing House, 231 pp. (in Chinese with English summary).
Zhuravlev, A. YU., Liñán, E., Gámez Vintaned, J. A., Debrenne, F. & Fedorov, A. B. 2012. New finds of skeletal fossils in the terminal Neoproterozoic of the Siberian Platform and Spain. Acta Palaeontologica Polonica 57, 205–24.


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The oldest Cambrian skeletal fossils of Spain (Cadenas Ibéricas, Aragón)



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