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Normalograptus kufraensis, a new species of graptolite from the western margin of the Kufra Basin, Libya

Published online by Cambridge University Press:  11 February 2013

ALEX PAGE ,
GUIDO MEINHOLD ,
DANIEL P. LE HERON  and
MOHAMED ELGADRY
ALEX PAGE*
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
GUIDO MEINHOLD
Affiliation:
CASP, University of Cambridge, West Building, 181A Huntingdon Road, Cambridge CB3 0DH, UK Department of Sedimentology & Environmental Geology, Geoscience Centre, University of Göttingen, Goldschmidtstraβe 3, 37077 Göttingen, Germany
DANIEL P. LE HERON
Affiliation:
Department of Earth Sciences, Queen's Building, Royal Holloway University of London, Egham, TW200EX, UK
MOHAMED ELGADRY
Affiliation:
Libyan Petroleum Institute, Gergarish Road, P. O. BOX 6431, Tripoli, Libya
*
†Author for correspondence: [email protected]
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Abstract

Normalograptus kufraensis sp. nov. occurs as monospecific assemblages in the Tanezzuft Formation at the western margin of the Kufra Basin (Jabal Eghei), southern Libya. These graptolites have parallel-sided rhabdosomes with long, straight virgellae, climacograptid thecae and a full straight median septum. N. kufraensis is intermediate between Ordovician graptolites from the N. angustus (Perner) lineage and the younger sister species N. ajjeri (Legrand) and N. arrikini Legrand. N. kufraensis differs from these taxa as follows: it is broader than N. angustus; it has greater thecal spacing than N. ajjeri or N. arrikini. A table comparing measurements of N. kufraensis with 44 other Normalograptus taxa differentiates it from other members of this morphologically conservative group. Even though N. angustus and N. ajjeri are very long-ranging graptolites, a stratophenetic approach suggests that the specimens from Jabal Eghei may be of late Hirnantian or younger age. The faunal composition and preservation suggests these graptolites occupied the ‘cratonic invader’ biotope. The stratigraphic succession records deglacial flooding and fluctuating of redox in the Tanezzuft Formation, with the graptolites indicating a short-lived interval of anoxia.

Keywords

biostratigraphySilurianGondwanaAfricaevolutionglaciationPalaeozoic
Type
Original Articles
Information
Geological Magazine , Volume 150 , Issue 4 , July 2013 , pp. 743 - 755
Copyright
Copyright © Cambridge University Press 2013 

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Footnotes

‡

Current address: Dauntsey's School, West Lavington, Wiltshire SN10 4EP, UK

References

Armstrong, H. A., Turner, B. R., Makhlouf, I. M., Weedon, G. P., Williams, M., Al Smadi, A. & Abu Salah, A. 2005. Origin, sequence stratigraphy and depositional environment of an upper Ordovician (Hirnantian) deglacial black shale, Jordan. Palaeogeography, Palaeoclimatology, Palaeoecology 220, 273–89.Google Scholar
Bellini, E., Giori, I., Ashuri, O. & Benelli, F. 1991. Geology of Al Kufra Basin, Libya. In The Geology of Libya, Vol. 6 (eds Salem, M. J., Sbeta, A. M. & Bakbak, M. R.), pp. 2155–84. Amsterdam: Elsevier.Google Scholar
Blackett, E. J., Page, A. A., Zalasiewicz, J. A., Williams, M., Rickards, R. B. & Davies, J. R. 2009. Refined graptolite biostratigraphy for the late Ordovician–early Silurian of central Wales. Lethaia 42, 83–96.Google Scholar
Briggs, D. E. G. & Williams, S. H. 1981. The restoration of fossil graptolites. Lethaia 14, 157–64.Google Scholar
Chen, X. & Lin, Y.-K. 1978. Lower Silurian graptolites from Tongzi, northern Guizhou. Memoirs of Nanjing Institute of Geology and Palaeontology, Academia Sinica 12, 1–75. [In Chinese]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., Rong, J., Mitchell, C. E., Harper, D. A. T., Fan, J., Zhan, R., Zhang, Y., Li, R. & 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
Cherns, L. & Wheeley, J. R. 2007. A pre-Hirnantian (Late Ordovician) interval of global cooling – the ‘Boda event’ reassessed. Palaeogeography, Palaeoclimatology, Palaeoecology 251, 449–60.Google Scholar
Churkin, C. & 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 TSQ, 1–51.Google Scholar
Davies, K. A. 1929. Notes on the graptolite faunas of the Upper Ordovician and Lower Silurian. Geological Magazine 66, 1–27.Google Scholar
Destombes, J., Holland, H. & Willefert, S. 1985. Lower Palaeozoic rocks of Morocco. In Lower Palaeozoic of North-Western and West-Central Africa. Lower Palaeozoic Rocks of the World, Vol. 4 (ed. Holland, C. H.), pp. 91–336. Chichester: John Wiley & Sons.Google Scholar
Elles, G. L. & Wood, E. M. R. 1907. A monograph of British graptolites. Part 6. Monograph of the Palaeontographical Society, London 61, 217–72.Google Scholar
Finney, S. C. & Berry, W. B. N. 1997. New perspectives on graptolite distributions and their use as indicators of platform margin dynamics. Geology 25, 919–22.Google Scholar
Fortey, R. A. & Cocks, L. R. M. 2005. Late Ordovician global warming – the Boda Event. Geology 33, 405–8.CrossRefGoogle Scholar
Ghienne, J.-F., Boumendjal, K., Paris, F., Videt, B., Racheboeuf, P. & Ait Salem, H. 2007. The Cambrian–Ordovician succession in the Ougarta Range (western Algeria, North Africa) and interference of the Late Ordovician glaciation on the development of the Lower Palaeozoic transgression on northern Gondwana. Bulletin of Geosciences 82, 183–214.Google Scholar
Goldman, D, Mitchell, C. E., Melchin, M. J., Fan, J-X. & Wu, S-Y. 2011. Biogeography and mass extinction: extirpation and re-invasion of Normalograptus species (Graptolithina) in the Late Ordovician Palaeo-tropics. Proceedings of the Yorkshire Geology Society 58, 227–46.Google Scholar
Goodarzi, F. & Norford, B. S. 1985. Graptolites as indicators of the temperature histories of rocks. Journal of the Geological Society, London 142, 1089–99.Google Scholar
Grignani, D., Lanzoni, E. & Elatrash, H. 1991. Paleozoic and Mesozoic subsurface palynostratigraphy in the Al Kufrah Basin, Libya. In The Geology of Libya, Vol. 4 (eds Salem, M. J., Hammuda, O. S. & Eliagoubi, B. A.), pp. 1159–228. Amsterdam: Elsevier.Google Scholar
Howe, M. P. A. 1983. Measurement of thecal spacing in graptolites. Geological Magazine 120, 635–8.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 (ed. Editorial Committee of Ministry of Geology and Mineral Resources), pp. 27–52. Beijing: Geological Publishing House. [In Chinese]Google Scholar
Hutt, J. E. 1974. The Llandovery graptolites of the English Lake District. Monograph of the Palaeontographical Society 128, 1–56.Google Scholar
Koren’, T. N. & Mikhaylova, N. F. 1980. Class Graptolithina. In The Ordovician–Silurian Boundary in Kazakhstan (eds Appollonov, M. K., Bandaletov, S. M. & Nikitkin, I. F.), pp. 1–300. Alma-Ata: Nauka Kazakhstan SSR Publishing House. [In Russian]Google Scholar
Koren’, T. N. & Melchin, M. J. 2000. Lowermost Silurian graptolites from the Kurama Range, eastern Uzbekistan. Journal of Paleontology 74, 1093–113.Google Scholar
Koren’, T. N. & Rickards, R. B. 2004. An unusually diverse Llandovery (Silurian) Diplograptid fauna from the Southern Urals of Russia and its evolutionary significance. Palaeontology 47, 859–918.Google Scholar
Jin, J. 2003. The Early Silurian brachiopod Eocoelia from the Hudson Bay Basin, Canada. Palaeontology 46, 885–902.Google Scholar
Lapworth, C. 1877. On the Graptolites of County Down. Proceedings of the Belfast Naturalists’ Field Club – Appendix 4, 125–44.Google Scholar
Lapworth, H. 1900. The Silurian sequence of Rhayader. Quarterly Journal of the Geological Society of London 56, 67–137.Google Scholar
Legrand, P. 1977. Contribution a 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
Legrand, P. 1986. The Silurian graptolites of Oued In Djerane: a study of populations at the Ordovician-Silurian boundary. In Palaeoecology and Biostratigraphy of Graptolites (eds Hughes, C. P. & Rickards, R. B.), pp. 1–277. Geological Society of London, Special Publication no. 20.Google Scholar
Legrand, P. 1987. Modo de desarrollo del Suborden Diplograptina (Graptolithina) en el Ordovícico Superior y en el Silúrico. Implicaciones taxonómicas. Revista Española de Paleontología 2, 59–64.Google Scholar
Legrand, P. 2000. Une région de référence pour la limite Ordovicien-Silurien: l'Oued In Djerane Sahara algérien. Comptes Rendus de l'Académie des sciences Paris, Sciences de la Terre et des planètes 330, 61–66.Google Scholar
Legrand, P. 2001. La faune graptolitique de la région d'In Azaoua (Tassili Oua-n-Ahaggar, confines algéro-nigériens). Annales de la Société Géologique du Nord 8, 137–58.Google Scholar
Legrand, P. 2003. Paléogéographie du Sahara algérien à l'Ordovicien terminal et au Silurien inférieur. Bulletin de la Société Géologique de France 174, 19–32.Google Scholar
Legrand, P. 2009. Faunal specificity, endemism and paleobiography: the post-glacial (Hirnantian-early Rhuddanian) graptolite fauna of the North-African border of Gondwana: a case study. Bulletin de la Société Géologique de France 180, 353–67.Google Scholar
Le Heron, D. P., Armstrong, H. A., Wilson, C., Howard, J. P. & Gindre, L. 2010. Glaciation and deglaciation of the Libyan Desert: the Late Ordovician record. Sedimentary Geology 223, 100–25.CrossRefGoogle Scholar
Le Heron, D. P. & Craig, J. 2008. First-order reconstructions of a Late Ordovician Saharan Ice Sheet. Journal of the Geological Society, London 165, 19–29.Google Scholar
Le Heron, D. P. & Howard, J. P. 2010. Evidence for Late Ordovician glaciation of Al Kufrah Basin, Libya. Journal of African Earth Sciences 58, 354–364.Google Scholar
Le Heron, D. P., Meinhold, G., Page, A. A. & Whitham, A. In press. Did lingering ice sheets moderate anoxia in the Early Palaeozoic of Libya? Journal of the Geological Society, London. doi:10.1144/jgs2012-108 Google Scholar
Le Heron, D. P., Sutcliffe, O. E., Whittington, R. J. & Craig, J. 2005. The origins of glacially related soft sediment deformation structures in Upper Ordovician glaciogenic rocks: implication for ice sheet dynamics. Palaeogeography, Palaeoclimatology, Palaeoecology 218, 75–103.Google Scholar
Li, J.-J. & Yang, X. C. 1983. In Palaeontological Atlas of East China, Part 1, Early Palaeozoic (ed. Nanjing Institute of Geology and Mineral Resources), pp. 1–657. Beijing: Geological Publishing House. [In Chinese]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. 2012 a. Graptolite biozone correlation charts. Geological Magazine 149, 124–32.Google Scholar
Loydell, D. K. 2012 b. Graptolite biostratigraphy of the E1-NC174 core, Rhuddanian (lower Llandovery, Silurian), Murzuq Basin (Libya). Bulletin of Geosciences 87, 651–60.Google Scholar
Loydell, D. K., Butcher, A., Frýda, J., Lüning, S. & Fowler, M. 2009. Lower Silurian “Hot Shales” in Jordan: a new depositional model. Journal of Petroleum Geology 32, 261–70.Google Scholar
Lüning, S., Craig, J., Fitches, W. R., Mayouf, J., Busrewil, A., El Dieb, M., Gammudi, A., Loydell, D. & McIlroy, D. 1999. Re-evaluation of the petroleum potential of the Kufra Basin SE Libya, NE Chad: does the source rock barrier fall? Marine and Petroleum Geology 16, 693–718.Google Scholar
Lüning, S., Craig, J., Loydell, D. K., Štorch, P. & Fitches, B. 2000. Lower Silurian ‘hot shales’ in North Africa and Arabia: regional distribution and depositional model. Earth-Science Reviews 49, 121–200.CrossRefGoogle Scholar
Manck, F. 1923. Untersilurische Graptolithenarten der Zone 10, ferner Diversograptus gen. nov., sowie einige neue Arten anderer Gattungen. Die Natur 14, 282–89.Google Scholar
M'Coy, F. 1850. On some new genera and species of Silurian Radiata in the collection of the University of Cambridge. Annals and Magazine of Natural History 6, 270–90.Google Scholar
Melchin, M. J. 1998. Morphology and phylogeny of some early Silurian ‘diplograptid’ genera from Cornwallis Island, Arctic Canada. Palaeontology 41, 263–315.Google Scholar
Melchin, M. J. 2008. Restudy of some Ordovician-Silurian boundary graptolites from Anticosti Island, Canada, and their biostratigraphic significance. Lethaia 41, 155–62.Google Scholar
Melchin, M. J. & Mitchell, C. E. 1991. Late Ordovician extinction in the Graptoloidea. In Advances in Ordovician Geology (eds Barnes, C. R. & Williams, S. H.), pp. 143–56. Geological Survey of Canada Paper no. 90–9.Google Scholar
Melchin, M. J., Mitchell, C. E., Naczk-Cameron, A., Fan, J-x. & Loxton, J. 2011. Phylogeny and adaptive radiation of the Neograpta (Graptoloida) during the Hirnantian mass extinction and Silurian recovery. Proceedings of the Yorkshire Geology Society 58, 281–309.Google Scholar
Mu, E.-Z. & Lin, Y.-K. 1984. Graptolites from the Ordovician-Silurian boundary sections of Yichang area, S. Hubei. In Stratigraphy and Palaeontology of Systemic Boundaries in China, Ordovician-Silurian Boundary Vol. 1 (ed. Nanjing Institute of Geology & Palaeontology, Academia Sinca), pp. 45–73. Hefei: Anhui Science and Technology Publishing House.Google Scholar
Mu, E.-Z. & Ni, Y.-N. 1983. Uppermost Ordovician and lower-most Silurian graptolites from Xainza area of Xizang (Tibet) with a discussion on the Ordovician–Silurian boundary. Paleontologia Cathayana 1, 155–79. [In Chinese]Google Scholar
Obut, A. M. & Sobolevskaya, R. F 1967. In Graptolites and Stratigraphy of the Lower Silurian along the Margins of the Kolyma Massif (eds Obut, A. M., Sobolevskaya, R. F. & Nikolaev, A. A.), pp. 1–164. Akademiya Nauk SSR, Sibirskoe otdelenie, Institut geologii i geofiziki, Ministerstvo geologii SSSR, Nauchno-issledovateľsky institut geologii Arktiky. [in Russian]Google Scholar
Page, A. A., Zalasiewicz, J. A., Williams, M. & Popov, L. E. 2007. Were transgressive black shales a negative feedback modulating glacioeustacy in the Early Palaeozoic icehouse? In Deep-Time Perspectives on Climate Change: Marrying the Signal from Computer Models and Biological Proxies (eds Williams, M., Haywood, A. M., Gregory, F. J. & Schmidt, D. N.), pp. 123–56. The Micropalaeontological Society, Special Publications. London: The Geological Society.Google Scholar
Perner, J. 1895. Études sur les Graptolites de Bohême. IIIième Partie. Monographie des Graptolites de l'Étage D. Prague: Raimond Gerhard, 31 pp.Google Scholar
Rickards, R. B. 1970. The Llandovery (Silurian) graptolites of the Howgill Fells, Northern England. Palaeontographical Society Monographs 123, 1–108.Google Scholar
Rickards, R. B. 2002. The graptolitic age of the type Ashgill Series (Ordovician), Cumbria, UK. Proceedings of the Yorkshire Geological Society 54, 1–16.Google Scholar
Rickards, R. B., Rigby, S., Rickards, J. & Swales, C. 1998. The hydrodynamics of graptolites assessed by laser Doppler anemometry. Palaeontology 41, 737–52.Google Scholar
Seilacher, A., Lüning, S., Martin, M.A., Klitzsch, E., Khoja, A. & Craig, J. 2002. Ichnostratigraphic correlation of Lower Palaeozoic clastics in the Kufra Basin (SE Libya). Lethaia 32, 257–62.Google Scholar
Sobolevskaya, R. F. 1974. New Ashgill graptolites in the middle flow basin of the Kolyma River. In Graptolites of the USSR (ed. Obut, A. M.), pp. 63–71. Novosibirsk: Nauka, Siberian Branch. [In Russian]Google Scholar
Štorch, P. 1989. Late Ordovician graptolites from the upper part of the Králův Dvůr Formation of the Prague Basin (Barrandian, Bohemia). Věstník Českého geologického ústavu 64, 173–86.Google Scholar
Štorch, P. & Feist, R. 2008. Lowermost Silurian graptolites of Montagne Noire, France. Journal of Paleontology 82, 938–56.Google Scholar
Štorch, P. & Massa, D. 2003. Biostratigraphy, correlation, environmental and biogeographic interpretation of the Lower Silurian graptolite faunas of Libya. In The Geology of Northwest Libya, Vol. 1 (eds Salem, M. J. & Oun, K. M.), pp. 237–51. Malta: Gutenberg Press Ltd.Google Scholar
Štorch, P., Mitchell, C. E., Finney, S. C. & Melchin, M. J. 2011. Uppermost Ordovician (upper Katian-Hirnantian) graptolites of north-central Nevada, USA. Bulletin of Geosciences 86, 301–86.Google Scholar
Štorch, P. & Serpagli, E. 1993. Lower Silurian graptolites from southwestern Sardinia. Bollettino della Società Paleontologica Italiana 32, 3–57.Google Scholar
Sun, Y.-Z. 1933. Ordovician and Silurian graptolites from China. Palaeontographica Sinica B14, 1–52. [In Chinese]Google Scholar
Sutcliffe, O. E., Harper, D. A. T., Salem, A. A., Whittington, R. J. & Craig, J. 2001. The development of an atypical Hirnantia brachiopod Fauna and the onset of glaciation in the late Ordovician of Gondwana. Earth and Environmental Science Transactions of the Royal Society of Edinburgh 92, 1–14.Google Scholar
Törnquist, S. L. 1897. On the Diplograptidae and Heteroprionidae of the Scanian Rastrites beds. Acta Universitatis Lundensis 33, 1–24.Google Scholar
Underwood, C. J. 1992. Graptolite preservation and deformation. Palaios 7, 178–86.Google Scholar
Underwood, C. J. & Bottrell, S. H. 1994. Diagenetic controls on the pyritization of graptolites. Geological Magazine 131, 315–27.Google Scholar
Underwood, C. J., Deynoux, M. & Ghienne, J.-F. 1998. High palaeolatitude (Hodh, Mauritania) recovery of graptolite fauna after the Hirnantian (end Ordovician) extinction event. Palaeogeography, Palaeoclimatology, Palaeoecology 142, 91–105.Google Scholar
Walker, L. J., Wilkinson, B. H., Ivany, L. C. 2002. Continental drift and Phanerozoic carbonate accumulation in shallow-shelf and deep-marine settings. Journal of Geology 110, 75–87.Google Scholar
Waern, B. 1948. The Silurian strata of the Kullatorp Core. In Deep Boring Through Ordovician and Silurian Strata at Kinnekulle, Vestergötland (eds Waern, B., Thorslund, P. & Henningsmoen, G.), pp. 433–74. Bulletin of the Geological Institutions of the University of Uppsala no. 32.Google Scholar
Williams, S. 1982 a. The Late Ordovician graptolite fauna of the Anceps Bands at Dob's Linn, southern Scotland. Geologica et Palaeontologica 16, 29–56.Google Scholar
Williams, S. H. 1982 b. Upper Ordovician graptolites from the top Lower Hartfell Shale Formation (D. clingani and P. linearis zones) near Moffat, southern Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences 72, 229–55.Google Scholar
Zalasiewicz, J. A. 2001. Graptolites as constraints on models of sedimentation across Iapetus: a review. Proceedings of the Geologists’ Association 112, 237–51.Google Scholar
Zalasiewicz, J. A., Taylor, L., Rushton, A. W. A., Loydell, D. K., Rickards, R. B. & Williams, M. 2009. Graptolites in British stratigraphy. Geological Magazine 146, 785–850.Google Scholar
Zalasiewicz, J. A. & Tunnicliff, S. P. 1994. Uppermost Ordovician to Lower Silurian graptolite biostratigraphy of the Wye valley, central Wales. Palaeontology 37, 695–720.Google Scholar
Zalasiewicz, J., Williams, M., Miller, M., Page, A. & Blackett, E. 2007. Early Silurian (Llandovery) graptolites from central Saudi Arabia: first documented record of Telychian faunas from the Arabian Peninsula. GeoArabia 12, 15–36.Google Scholar
Ziegler, A. M., Cocks, L. R. M. & Bambach, R. K. 1968. The composition and structure of Lower Silurian marine communities. Lethaia 1, 1–27.Google Scholar