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A late surviving xenopod (Arthropoda) from the Ordovican Period, Wales

Published online by Cambridge University Press:  19 June 2015

DAVID A. LEGG  and
THOMAS W. HEARING
DAVID A. LEGG*
Affiliation:
Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, UK
THOMAS W. HEARING
Affiliation:
Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3PR, UK Current address: Department of Geology, University of Leicester, University Road, Leicester LE1 7RH, UK
*
†Author for correspondence: david.legg@oum.ox.ac.uk
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Abstract

The Middle Ordovician Llanfallteg Formation has yielded remains of soft-bodied organisms previously known only from Cambrian Burgess Shale-type deposits. A new arthropod Etania howellsorum gen. et sp. nov. is described here, characterized by a semi-circular cephalon, clusters of spinose endites on the endopod and exopods with ovoid distal lobes. These characters are consistent with xenopod affinities, a clade otherwise known exclusively from the Cambrian Period. The discovery of E. howellsorum demonstrates that a number of Burgess Shale-type taxa, including xenopods, survived past the Cambrian Period (albeit within a restricted environment) and may have been outcompeted during the Great Ordovician Biodiversification Event (GOBE).

Keywords

EmeraldellaSidneyiaVicissicaudataCambrian faunaPalaeozoic fauna
Type
Rapid Communication
Information
Geological Magazine , Volume 152 , Issue 5 , September 2015 , pp. 942 - 948
Copyright
Copyright © Cambridge University Press 2015 

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References

Aldridge, R. J., Gabbott, S. E. & Theron, J. N. 2001. The soom shale. In Palaeobiology II (eds Briggs, D. E. G. & Crowther, P. R.), pp. 340–2. Oxford: Blackwell Science.CrossRefGoogle Scholar
Allison, P. A. & Briggs, D. E. G. 1993. Exceptional fossil record: Distribution of soft-tissue preservation through the Phanerozoic. Geology 21, 527–30.Google Scholar
Brenchley, P. J., Rushton, A. W. A., Howells, M. & Cave, R. 2006. Cambrian and Ordovician: the early Palaeozoic tectonostratigraphic evolution of the Welsh Basin, Midland and Monian Terranes of Eastern Avalonia. In The Geology of England and Wales (eds Brenchley, P. J. & Rawson, P. F.), pp. 25–75. London: The Geological Society.Google Scholar
Briggs, D. E. G. & Collins, D. 1988. A Middle Cambrian chelicerate from Mount Stephen, British Columbia. Palaeontology 31, 779–98.Google Scholar
Briggs, D. E. G., Lieberman, B. S., Hendricks, J. R., Halgedahl, S. L. & Jarrard, R. D. 2008. Middle Cambrian arthropods from Utah. Journal of Paleontology 82, 238–54.Google Scholar
Briggs, D. E. G. & Robison, R. A. 1984. Exceptionally preserved nontrilobite arthropods and Anomalocaris from the middle Cambrian of Utah. The University of Kansas Paleontological Contributions 111, 1–23.Google Scholar
Bruton, D. L. 1981. The arthropod Sidneyia inexpectans, Middle Cambrian, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 295, 619–53.Google Scholar
Bruton, D. L. & Whittington, H. B. 1983. Emeraldella and Leanchoilia, two arthropods from the Burgess Shale, Middle Cambrian, British Columbia. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 300, 553–82.Google Scholar
Brysse, K. 2008. From weird wonder to stem lineages: the second reclassification of the Burgess Shale fauna. Studies in History and Philosophy of Biological and Biomedical Sciences 39, 298–313.CrossRefGoogle ScholarPubMed
Budd, G. E. 2002. A palaeontological solution to the arthropod head problem. Nature 417, 271–5.Google Scholar
Budd, G. E. & Jensen, S. 2000. A critical reappraisal of the fossil record of the bilaterian phyla. Biological Reviews 75, 253–95.Google Scholar
Conway Morris, S. 1989. The persistence of Burgess Shale-type faunas: implications for the evolution of deeper-water faunas. Transactions of the Royal Society of Edinburgh: Earth Sciences 80, 271–83.CrossRefGoogle Scholar
Cotton, T. & Braddy, S. J. 2004. The phylogeny of arachnomorph arthropods and the origins of Chelicerata. Transactions of the Royal Society of Edinburgh: Earth Sciences 94, 169–93.Google Scholar
Dunlop, J. A. & Selden, P. A. 1997. The early history and phylogeny of the chelicerates. In Arthropod Relationships (eds Fortey, R. A. & Thomas, R. H.), pp. 221–35. The Systematic Association, Special Volume Series 55.Google Scholar
Edgecombe, G. D., García-Bellido, D. C. & Paterson, J. R. 2011. A new leanchoiliid megacheiran arthropod from the lower Cambrian Emu Bay Shale, South Australia. Acta Palaeontologica Polonica 56, 385–400.Google Scholar
Edgecombe, G. D. & Ramsköld, L. 1999. Relationships of Cambrian Arachnata and the systematic position of Trilobita. Journal of Paleontology 73, 263–87.Google Scholar
Farrell, U. C., Martin, M. J., Hagadorn, J. W., Whiteley, T. & Briggs, D. E. G. 2009. Beyond Beecher's Trilobite Bed: widespread pyritisation of soft-tissues in the Late Ordovician Taconic foreland basin. Geology 37, 907–10.Google Scholar
Fortey, R. A., Harper, D. A. T., Ingham, J. K., Owen, A. W., Parkes, M. A., Rushton, A. W. A. & Woodcock, N. H. 2000. A revised correlation of Ordovician Rocks in the British Isles. Geological Society of London, Special Report 24.Google Scholar
Fortey, R. A. & Owens, R. M. 1987. The Arenig Series in South Wales: stratigraphy and palaeontology. Bulletin of the British Museum of Natural History (Geology) 41, 69–307.Google Scholar
Gaines, R. R., Droser, M. L., Orr, P. J., Garson, D., Hammarlund, E., Qi, C. & Canfield, D. E. 2012. Burgess shale-type biotas were not entirely burrowed away. Geology 40, 283–6.Google Scholar
Gould, S. J. 1989. Wonderful Life. The Burgess Shale and the Nature of History. New York: Norton, 352 pp.Google Scholar
Jablonski, D., Sepkoski, Jr., J. J., Bottjer, D. J. & Sheehan, P. M. 1983. Onshore-offshore patterns in the evolution of Phanerozoic shelf communities. Science 222, 1123–5.Google Scholar
Hou, X. & Bergström, J. 1997. Arthropods of the Lower Cambrian Chengjiang fauna, southwest China. Fossils and Strata 45, 1–116.Google Scholar
Legg, D. A. 2014. Sanctacaris uncata: the oldest chelicerate (Arthropoda). Naturwissenshaften 101 (12), 1065–73.Google Scholar
Legg, D. A., Sutton, M. D. & Edgecombe, G. D. 2013. Arthropod fossil data increase congruence of morphological and molecular phylogenies. Nature Communications 4, 2485.CrossRefGoogle ScholarPubMed
Legg, D. A., Sutton, M. D., Edgecombe, G. D. & Caron, J.-B. 2012. Cambrian bivalved arthropod reveals origin of arthrodization. Proceedings of the Royal Society of London B 279, 4699–704.Google Scholar
Lerosey-Aubril, R., Ortega-Hernández, J., Kier, C. & Bonino, E. 2013. Occurrence of the Ordovician-type aglaspidid Tremaglaspis in the Cambrian Weeks Formation (Utah, USA). Geological Magazine 150, 945–51.CrossRefGoogle Scholar
Liu, H. P., McKay, R. M., Young, J. N., Witzke, B. J., McVey, K. J. & Liu, X. 2006. A new Lagerstätte from the Middle Ordovician St. Peter Formation in northeast Iowa, USA. Geology 34, 969–72.Google Scholar
Orr, P. J., Benton, M. J. & Briggs, D. E. G. 2003. Post-Cambrian closure of the deep-water slope-basin taphonomic window. Geology 31, 769–72.Google Scholar
Ortega-Hernández, J., Legg, D. A. & Braddy, S. J. 2013. The phylogeny of aglaspidid arthropods and the internal relationships within Artiopoda. Cladistics 29, 15–45.Google Scholar
Paterson, J. R., Edgecombe, G. D., García-Bellido, D. C., Jago, J. B. & Gehling, J. G. 2010. Nektaspid arthropods from the lower Cambrian Emu Bay Shale Lagerstätte, South Australia, with a reassessment of lamellipedian relationships. Palaeontology 81, 116–42.Google Scholar
Paterson, J. R., García-Bellido, D. C. & Edgecombe, G. D. 2012. New artiopodan arthropods from the Early Cambrian Emu Bay Shale Konservat-Lagerstätte of South Australia. Journal of Paleontology 86, 340–57.Google Scholar
Rak, Š., Ortega-Hernández, J. & Legg, D. A. 2013. A revision of the Late Ordovician marrellomorph arthropod Furca bohemica from Czech Republic. Acta Palaeontologica Polonica 58, 615–28.Google Scholar
Raymond, P. E. 1935. Leanchoilia and other Mid-Cambrian Arthropoda. Museum of Comparative Zoology Bulletin 76, 205–30.Google Scholar
Sepkoski, J. J. 1981. A factor analysis description of the Phanerozoic marine fossil record. Palaeobiology 7, 3–53.Google Scholar
Siebold, C. T. von. 1848. Lehrbuch der vergleichende Anatomie der Wirbellosen Thiere. Erster Theil. In Lehrbuch der Vergleichende Anatomie (eds von, C. T. Siebold & Stannius, H.), pp. 1–679. Leipzig: Verlag von Veit & Company.Google Scholar
Stein, M. 2013. Cephalic and appendage morphology of the Cambrian arthropod Sidneyia inexpectans Walcott, 1911. Zoologischer Anzeiger 253, 164–78.CrossRefGoogle Scholar
Stein, M., Church, S. B. & Robison, R. A. 2011. A new Cambrian arthropod, Emeraldella brutoni, from Utah. University of Kansas Paleontological Contributions 3, 1–9.Google Scholar
Stein, M. & Selden, P. A. 2012. A restudy of the Burgess Shale (Cambrian) arthropod Emeraldella brocki and reassessment of its affinities. Journal of Systematic Palaeontology 10, 361–83.Google Scholar
Van Roy, P., Orr, P., Botting, J., Muir, L., Vinther, J., Lefevbre, B., Hariri, K. & Briggs, D. E. G. 2010. Ordovician faunas of Burgess Shale type. Nature 464, 215–8.Google Scholar
Webby, B. D., Paris, F., Droser, M. L. & Percival, I. G. (eds) 2004. The Great Ordovician Biodiversification Event. New York: Columbia University Press.Google Scholar
Whittington, H. B. 1981. Rare arthropods from the Burgess Shale, Middle Cambrian, British Columbia. Philosophical Transactions of the Royal Society of London B, Biological Sciences 292, 329–57.Google Scholar
Whittington, H. B. 1993. Anatomy of the Ordovician trilobite Placoparia . Philosophical Transactions of the Royal Society of London B 339, 109–18.Google Scholar
Young, G. A., Rudkin, D. M., Dobrzanski, E. P., Robson, S. P. & Nowlan, G. S. 2007. Exceptionally preserved Late Ordovician biotas from Manitoba, Canada. Geology 35, 883–6.Google Scholar
Zhang, X., Han, J. & Shu, D. 2002. New occurrence of the Burgess Shale arthropod Sidneyia in the Early Cambrian Chengjiang Lagerstätte (South China), and revision of the arthropod Urokodia . Alcheringa 26, 1–8.Google Scholar
Zhang, X.-L. & Shu, D.-G. 2005. A new arthropod from the Chengjiang Lagerstätte, Early Cambrian, southern China. Alcheringa 29, 185–94.Google Scholar