Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-25T14:11:50.367Z Has data issue: false hasContentIssue false
  • English
  • Français

The taphonomy and affinities of the problematic fossil Myoscolex from the Lower Cambrian Emu Bay Shale of South Australia

Published online by Cambridge University Press:  20 May 2016

Derek E. G. Briggs  and
Christopher Nedin
Derek E. G. Briggs
Affiliation:
Department of Geology, University of Bristol, Wills Memorial Building, Queen's Road, Bristol, BS8 1RJ, U.K.
Christopher Nedin
Affiliation:
Department of Geology and Geophysics, University of Adelaide, South Australia 5005
Get access Rights & Permissions [Opens in a new window]

Abstract

Most of the specimens of Myoscolex ateles Glaessner, 1979, the most abundant soft-bodied taxon in the Big Gully fauna from the Lower Cambrian Emu Bay Shale of South Australia, preserve only the phosphatized trunk muscles, in striking contrast to the organic residues that characterize other Burgess-Shale-type biotas. This is the oldest phosphatized muscle tissue and the first thus far reported from the Cambrian. The extent of phosphatization implies a source in addition to the animal itself, and this is reflected in high levels of phosphate in the Big Gully sequence compared to other shales. The apparent anomaly posed by the extensive preservation of labile muscle tissue as opposed to the more decay resistant cuticle is explained by the role of bacterial processes in the preservation of soft tissues. New specimens of Myoscolex reveal a variable number of trunk somites with possible tergites, and flap-like appendages. There is evidence for at least three eyes on the head, and a proboscis may have been present. An annelid affinity is rejected and Myoscolex is reinterpreted as an Opabinia-like animal with possible affinities with the arachnomorph arthropods.

Type
Research Article
Information
Journal of Paleontology , Volume 71 , Issue 1 , January 1997 , pp. 22 - 32
Copyright
Copyright © The Paleontological Society 

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

Allison, P. A. 1988. Konservat-Lagerstätten: Cause and classification. Paleobiology, 14:331–344.Google Scholar
Allison, P. A., and Briggs, D. E. G. 1991. Taphonomy of nonmineralized tissues, p. 25–70. In Allison, P. A. and Briggs, D. E. G. (eds.), Taphonomy: releasing the data locked in the fossil record. Plenum, New York.Google Scholar
Allison, P. A., and Briggs, D. E. G. 1993. Exceptional fossil record: distribution of soft-tissue preservation through the Phanerozoic. Geology, 21:527–530.Google Scholar
Bale, S. J., Briggs, D. E. G., Parkes, R. J., and Wilby, P. R. 1996. The controls on decay and mineralization — the key to the fossilization of soft tissues. Proceedings of the 6th North American Paleontological Convention, Abstracts with Programs. The Paleontological Society Special Publication, 8:21.Google Scholar
Bengtson, S., Conway Morris, S., Cooper, B. J., Jell, P. A., and Runnegar, B. N. 1990. Early Cambrian fossils from South Australia. Memoir of the Association of Australasian Palaeontologists, 9, 364 p.Google Scholar
Bergström, J. 1986. Opabinia and Anomalocaris, unique Cambrian ‘arthropods’. Lethaia, 19:241–246.Google Scholar
Biseswar, R. 1991. Burrowing, locomotion and other movements of the Echiuran Ochetostoma caudex. Acta Zoologica, 72:91–99.CrossRefGoogle Scholar
Briggs, D. E. G. and Kear, A. J. 1993. Decay and preservation of polychaetes: taphonomic thresholds in soft-bodied organisms. Paleobiology, 19:107–135.Google Scholar
Briggs, D. E. G. and Kear, A. J. 1994. Decay and mineralization of shrimps. Palaios, 9:431–456.CrossRefGoogle Scholar
Briggs, D. E. G., Erwin, D. H., and Collier, F. J. 1994. The fossils of the Burgess Shale, 238 p. Smithsonian Institution Press, Washington and London.Google Scholar
Briggs, D. E. G., Kear, A. J., Martill, D. M., and Wilby, P. R. 1993. Phosphatization of soft-tissue in experiments and fossils. Journal of the Geological Society of London, 150:1035–1038.CrossRefGoogle Scholar
Briggs, D. E. G. and Wilby, P. R. 1996. The role of the calcium carbonate / calcium phosphate switch in the mineralization of soft-bodied fossils. Journal of the Geological Society of London, 153, 665–668.Google Scholar
Budd, G. 1993. A Cambrian gilled lobopod from Greenland. Nature, 364:709–711.Google Scholar
Butterfield, N. J. 1990. Organic preservation of non-mineralizing organisms and the taphonomy of the Burgess Shale. Paleobiology, 16:272–286.Google Scholar
Butterfield, N. J. 1995. Secular distribution of Burgess Shale-type preservation. Lethaia, 28:1–13.Google Scholar
Chen, J-Y. and Erdtmann, B.-D. 1991. Lower Cambrian lagerstätte from Chengjiang, Yunnan, China: insights for reconstructing early metazoan life, p. 57–76. In Simonetta, A. M. and Conway Morris, S. (eds.), The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press.Google Scholar
Chen, J-Y., Ramskold, L., and Zhou, G-Q. 1994. Evidence for monophyly and arthropod affinity of Cambrian giant predators. Science, 264:1304–1308.CrossRefGoogle ScholarPubMed
Collins, D. 1996. The ‘evolution’ of Anomalocaris: a paradigm for understanding Cambrian life. Journal of Paleontology, 70:280–293.Google Scholar
Conway Morris, S. 1979. Middle Cambrian polychaetes from the Burgess Shale of British Columbia. Philosophical Transactions of the Royal Society of London, B285:227–274.Google Scholar
Conway Morris, S. 1985. Cambrian Lagerstätten: their distribution and significance. Philosophical Transactions of the Royal Society of London, B311:49–65.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, 80:271–283.CrossRefGoogle Scholar
Daily, B. 1956. The Cambrian in South Australia. 20th International Geological Congress, Mexico, 2:91–147.Google Scholar
Daily, B., Moore, P. S., and Rust, B. R. 1980. Terrestrial-marine transition in the Cambrian rocks of Kangaroo Island, South Australia. Sedimentology, 27:379–399.Google Scholar
Dinnick, M. 1985. Stratigraphy, sedimentology and palaeontology of a Cambrian molassic sequence, Cape D'Estaing to Point Marsden, north east coast of Kangaroo Island, South Australia. Unpublished Honors Thesis, University of Adelaide, 23 p.).Google Scholar
Gabbott, S. E., Aldridge, R. J., and Theron, J. N. 1995. A giant conodont with preserved muscle tissue from the Upper Ordovician of South Africa. Nature, 374:800–803.Google Scholar
Glaessner, M. F. 1979. Lower Cambrian Crustacea and annelid worms from Kangaroo Island, South Australia. Alcheringa, 3:21–31.Google Scholar
Hou, X-G. and Bergström, J. 1991. The arthropods of the Lower Cambrian Chengjiang fauna, with relationships and evolutionary significance, p. 179–187. In Simonetta, A. M. and Conway Morris, S. (eds.), The early Evolution of Metazoa and the Significance of Problematic taxa. Cambridge University Press.Google Scholar
Hou, X-G., and Chen, J-Y. 1989. Early Cambrian arthropod-annelid intermediate sea animal, Luolishania gen. nov. from Chengjiang, Yunnan. Acta Palaeolontologica Sinica, 28:211–227. [In Chinese with English abstract]Google Scholar
HouX-G., X-G. X-G., X-G., Bergström, J., and Ahlberg, P. 1995. Anomalocaris and other large animals in the Lower Cambrian Chengjiang fauna of southwest China. Geologiska Föreningens i Stockholm Förhandlingar, 117:163–183.Google Scholar
Hou, X-G., Ramsköld, L., and Bergstrom, J. 1991. Composition and preservation of the Chengjiang fauna—a Lower Cambrian soft-bodied biota. Zoologica Scripta, 20:395–411.Google Scholar
Kear, A. J., Briggs, D. E. G., and Donovan, D. T. 1995. Decay and fossilisation of non-mineralised tissue in coleoid cephalopods. Palaeontology, 38:105–131.Google Scholar
Martill, D. M. 1988. Preservation of fish in the Cretaceous of Brazil. Palaeontology, 31:1–18.Google Scholar
Martill, D. M. 1990. Macromolecular resolution of fossilized muscle tissues from an elopomorph fish. Nature, 346:171–172.CrossRefGoogle Scholar
McHenry, B., and Yates, A. 1993. First report of the enigmatic metazoan Anomalocaris from the Southern Hemisphere and a trilobite with preserved appendages from the Early Cambrian of Kangaroo Island, South Australia. Records of the South Australian Museum, 26:77–86.Google Scholar
Nedin, C. 1992. The palaeontology and palaeoecology of the Lower Cambrian Emu Bay Shale, Kangaroo Island, South Australia. Proceedings of the 5th North American Paleontological Convention, Abstracts with Programs. The Paleontological Society Special Publication, 6:221.Google Scholar
Nedin, C. 1995a. The Emu Bay Shale, a Lower Cambrian fossil Lagerstätten, Kangaroo Island, South Australia. Memoir of the Association of Australasian Palaeontologists, 18:31–40.Google Scholar
Nedin, C. 1995b. The palaeontology and palaeoecology of the Lower Cambrian Emu Bay Shale, Kangaroo Island, South Australia. Unpublished PhD Thesis, University of Adelaide, 207pp.Google Scholar
Öpik, A. A. 1975. Cymbric Vale fauna of New South Wales and Early Cambrian biostratigraphy. Bureau of Mineral Resources, Geology and Geophysics Bulletin, 159:1–78.Google Scholar
Pocock, K. J. 1964. Estaingia, a new trilobite genus from the Lower Cambrian of South Australia. Palaeontology, 7:458–471.Google Scholar
Qian, Y., and Bengtson, S. 1989. Palaeontology and biostratigraphy of the Early Cambrian Meishucunian Stage in Yunnan Province, south China. Fossils and Strata, 24:1–156.Google Scholar
Stephen, A. C., and Edmonds, S. J. 1972. The Phyla Sipuncula and Echiura. British Museum (Natural History), London, 528 p.Google Scholar
Thompson, I. 1979. Errant polychaetes (Annelida) from the Pennsylvanian Essex fauna of northern Illinois. Palaeontographica A, 163:169–199.Google Scholar
Wedepohl, K. H. 1971. Environmental influences on the chemical composition of shales and clays, p. 305–334. In Ahrens, L. H., Press, F., Runcorn, S. K. and Urey, H. C. (eds.), Physics and Chemistry of the Earth, Volume 8. Pergamon Press.Google Scholar
Whittington, H. B. 1975. The enigmatic animal Opabinia regalis, Middle Cambrian, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London, B271:1–43.Google Scholar
Whittington, H. B., and Briggs, D. E. G. 1985. The largest Cambrian animal, Anomalocaris, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London, B309:569–609.Google Scholar
Wills, M. A., Briggs, D. E. G., Fortey, R. A., and Wilkinson, M. 1995. The significance of fossils in understanding arthropod evolution. Verhandlungen der Deutschen Zoologischen Gesellschaft, 88:203–215.Google Scholar
Wills, M. A., Briggs, D. E. G., Fortey, R. A., Wilkinson., M., and Sneath, P.H.A. 1997. An arthropod phylogeny based on fossil and Recent taxa. In Edgecombe, G. E. (ed.), Arthropod Fossils and Phylogeny. Columbia University Press, New York.Google Scholar
Zhang, W., Lu, Y., Zhu, Z., Qian, Y., Lin, H., Zhou, Z., Zhang, S.S., and Yuan, J. 1980. Cambrian trilobite faunas of southwest China. Acta Palaeontographica Sinica, 16:1–497. [In Chinese with English summary]Google Scholar