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The “evolution” of Anomalocaris and its classification in the arthropod class Dinocarida (nov.) and order Radiodonta (nov.)

Published online by Cambridge University Press:  20 May 2016

Desmond Collins*
Affiliation:
Department of Invertebrate Palaeontology, Royal Ontario Museum, Toronto, Ontario, M5S 2C6 Canada

Abstract

The remarkable “evolution” of the reconstructions of Anomalocaris, the extraordinary predator from the 515 million year old Middle Cambrian Burgess Shale of British Columbia, reflects the dramatic changes in our interpretation of early animal life on Earth over the past 100 years. Beginning in 1892 with a claw identified as the abdomen and tail of a phyllocarid crustacean, parts of Anomalocaris have been described variously as a jellyfish, a sea-cucumber, a polychaete worm, a composite of a jellyfish and sponge, or have been attached to other arthropods as appendages. Charles D. Walcott collected complete specimens of Anomalocaris nathorsti between 1911 and 1917, and a Geological Survey of Canada party collected an almost complete specimen of Anomalocaris canadensis in 1966 or 1967, but neither species was adequately described until 1985. At that time they were interpreted by Whittington and Briggs to be representatives of “a hitherto unknown phylum.”

Here, using recently collected specimens, the two species are newly reconstructed and described in the genera Anomalocaris and Laggania, and interpreted to be members of an extinct arthropod class, Dinocarida, and order Radiodonta, new to science. The long history of inaccurate reconstruction and mistaken identification of Anomalocaris and Laggania exemplifies our great difficulty in visualizing and classifying, from fossil remains, the many Cambrian animals with no apparent living descendants.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

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References

Bassler, R. S., Resser, C. E., Schmttt, W. L., and Bartsch, P. 1931. Shelled invertebrates of the past and present. Smithsonian Scientific Series, 10, 365 p.Google Scholar
Benton, M. J. (ed.). 1993. The Fossil Record 2. Chapman and Hall, London, 845 p.Google Scholar
Bergström, J. 1986. Opabinia and Anomalocaris, unique Cambrian ‘arthropods'. Lethaia, 19:241246.CrossRefGoogle Scholar
Briggs, D. E. G. 1979. Anomalocaris, the largest known Cambrian arthropod. Palaeontology, 22:631664.Google Scholar
Briggs, D. E. G. 1994. Giant predators from the Cambrian of China. Science, 264:12831284.CrossRefGoogle ScholarPubMed
Briggs, D. E. G. and Fortey, R. A. 1989. The early radiation and relationships of the major arthropod groups. Science, 246:241243.CrossRefGoogle ScholarPubMed
Brusca, R. C., and Brusca, G. J. 1990. Invertebrates. Sinauer Associates, Inc., Sonderland, Massachusetts, 922 p.Google Scholar
Bruton, D. L. 1981. The arthropod Sidneyia inexpectans, Middle Cambrian, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London, B 295:619656.Google Scholar
Budd, G. 1993. A Cambrian gilled lobopod from Greenland. Nature, 364:709711.Google Scholar
Chen, J-Y., Bergström, J., Lindström, M., and Hou, X-G. 1991. Fossilized soft-bodied fauna. National Geographic Research and Exploration, 7:819.Google Scholar
Chen, J-Y., Bergström, J., Lindström, M., and Hou, X-G. Ramsköld, L., and Zhou, G-O. 1994. Evidence for monophyly and arthropod affinity of Cambrian giant predators. Science, 264:13041308.Google Scholar
Collins, D. 1984. Glossopleura fauna of the Burgess Shale type in the Middle Cambrian Stephen Formation of the Canadian Rocky Mountains. Abstract. 27th International Geological Congress, Moscow, 1:251252.Google Scholar
Collins, D. 1986. The great Anomalocaris mystery. Rotunda, 19(3):5157.Google Scholar
Collins, D. 1989. Another new Burgess Shale fauna. Abstracts 28th International Geological Congress, Washington, 1:314.Google Scholar
Collins, D. 1992. Whither Anomalocaris? The search in the Burgess Shale continues. Abstracts, 5th North American Paleontological Convention, Chicago, Paleontological Society Special Publication, 6:66.Google Scholar
Collins, D., Briggs, D. E. G., and Conway Morris, S. 1983. New Burgess Shale sites reveal Middle Cambrian faunal complex. Science, 222:163167.Google Scholar
Conway Morris, S. 1978. Laggania cambria Walcott: A composite fossil. Journal of Paleontology, 52:126131.Google Scholar
Conway Morris, S. 1993. The fossil record and the early evolution of the Metazoa. Nature, 361:219225.CrossRefGoogle Scholar
Conway Morris, S., and Whittinoton, H. B. 1979. The animals of the Burgess Shale. Scientific American, 241:122133.Google Scholar
Delle Cave, L., and Simonetta, A. M. 1991. Early Palaeozoic arthropods and problems of arthropod phylogeny; with some notes on taxa of doubtful affinities, p. 189244. In Simonetta, A. M. and Conway Morris, S. (eds.), The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press, New York.Google Scholar
Dzik, J., and Lendzion, K. 1988. The oldest arthropods of the East European Platform. Lethaia, 21:2938.Google Scholar
Gould, S. J. 1989. Wonderful Life: The Burgess Shale and the Nature of History. W. W. Norton and Co., New York, 347 p.Google Scholar
Henriksen, K. L. 1928. Critical notes upon some Cambrian arthropods described by Charles D. Walcott. Videnskabelige Meddelelser fra Dansk Naturhistorisk Forening: Khobenhavn, 86:120.Google Scholar
Hou, X-G., Bergström, J., and Ahlberg, P. 1995. Anomalocaridids from the Lower Cambrian Chengjiang fauna of southwest China. Abstracts, International Cambrian Explosion Symposium, Nanjing:5.Google Scholar
Knight, C. R. 1942. Parade of life through the ages. National Geographic Magazine, 81:141184.Google Scholar
Madsen, F. J. 1957. On Walcott's supposed Cambrian holothurians. Journal of Paleontology, 31:281282.Google Scholar
Meglitsch, P. A., and Schram, F. R. 1991. Invertebrate Zoology (third edition). Oxford University Press, Oxford, 623 p.Google Scholar
Ramsköld, L. 1995. From characters to clades: interpreting Lobopodians and Anomalocaridids. Abstracts, International Cambrian Explosion Symposium, Nanjing:22.Google Scholar
Simonetta, A. M., and Delle Cave, L. 1975. The Cambrian nontrilobite arthropods from the Burgess Shale of British Columbia. A study of their comparative morphology, taxinomy [sic] and evolutionary significance. Palaeontographica Italica, 69(new series 39):137.Google Scholar
Walcott, C. D. 1888. Cambrian fossils from Mount Stephens, Northwest Territory of Canada. American Journal of Science, 36:161166.Google Scholar
Walcott, C. D. 1889. Description of new genera and species of fossils from the Middle Cambrian. Proceedings of the United States National Museum 11:441446.CrossRefGoogle Scholar
Walcott, C. D. 1908. Mount Stephen rocks and fossils. Canadian Alpine Journal, 1(2):232248.Google Scholar
Walcott, C. D. 1911a. Middle Cambrian Merostomata. Cambrian geology and paleontology II. Smithsonian Miscellaneous Collections, 57:1740.Google Scholar
Walcott, C. D. 1911b. Middle Cambrian Holothurians and Medusae. Cambrian geology and paleontology II. Smithsonian Miscellaneous Collections, 57:4168.Google Scholar
Walcott, C. D. 1911c. Middle Cambrian Annelids. Cambrian geology and paleontology II. Smithsonian Miscellaneous Collections, 57:109144.Google Scholar
Walcott, C. D. 1912. Middle Cambrian Branchiopoda, Malacostraca, Trilobita and Merostomata. Cambrian geology and paleontology II. Smithsonian Miscellaneous Collections, 57:145228.Google Scholar
Whiteaves, J. F. 1892. Description of a new genus and species of Phyllocarid Crustacea from the Middle Cambrian of Mount Stephen, B.C. Canadian Record of Science, 5:205208.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, B 271:143.Google Scholar
Whittington, H. B. and Briggs, D. E. G. 1982. A new conundrum from the Middle Cambrian Burgess Shale. Proceedings of the Third North American Paleontological Convention, Montreal, 2:573575.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, B 309:569609.Google Scholar
Woodward, H. 1902. The Canadian Rockies. Part I: On a collection of Middle Cambrian fossils obtained by Edward Whymper, Esq., F.R.G.S., from Mount Stephen, British Columbia. Geological Magazine, 4(9):502505, 529-544.Google Scholar