Chinese Science Bulletin

, Volume 52, Issue 24, pp 3385–3392 | Cite as

A Cambrian micro-lobopodian and the evolution of arthropod locomotion and reproduction

  • Andreas Maas
  • Georg Mayer
  • Reinhardt M. Kristensen
  • Dieter Waloszek
Articles Geology


The evolutionary success of arthropods, the most abundant and diverse animal group, is mainly based on their segmented body and jointed appendages, features that had evolved most likely already before the Cambrian. The first arthropod-like animals, the lobopodians from the Early Cambrian, were unsclerotized and worm-like, and they had unjointed tubular legs. Here we describe the first three-dimensionally preserved Cambrian lobopodian. The material presented of Orstenotubulus evamuellerae gen. et sp. nov. is the smallest and youngest of a lobopodian known. O. evamuellerae shows strikingly detailed similarities to Recent tardigrades and/or onychophorans in its cellular-structured cuticle and the telescopic spines. It also shows similarities to other, longer known lobopodians, but which are ten times as large as the new form. These similarities include the finely annulated body and legs, which is characteristic also for Recent onychophorans, and paired humps continuing into spines situated dorsally to the leg insertions, a feature lacking in the extant forms. The morphology of O. evamuellerae not only elucidates our knowledge about lobopodians, but also aids in a clearer picture of the early evolution of arthropods. An example is the single ventral gonopore between a limb pair of O. evamuellerae, which indicates that a single gonopore, as developed in onychophorans, tardigrades, pentastomids, myriapods and insects, might represent the plesiomorphic state for Arthropoda, while the paired state in chelicerates and crustaceans was convergently achieved. Concerning life habits, the lateral orientation of the limbs and their anchoring spines of the new lobopodian imply that early arthropods were crawlers rather than walkers.

Key words

lobopodians Arthropoda evolution phylogeny reproductive system locomotion 


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  1. 1.
    Maas A, Waloszek D, Chen J Y, et al. Phylogeny and life habits of early arthropods—predation in the early Cambrian sea. Prog Nat Sci, 2004, 14: 1–9CrossRefGoogle Scholar
  2. 2.
    Waloszek D, Chen J Y, Maas A, et al. Early Cambrian arthropods—new insights into arthropod head and structural evolution. Arthr Str Dev, 2005, 34: 189–205CrossRefGoogle Scholar
  3. 3.
    Conway Morris S, Whittington H B, Briggs D E G, et al. Atlas of the Burgess Shale. London: The Palaeontological Association, 1982Google Scholar
  4. 4.
    Ramsköld L, Hou X G. New early Cambrian animal and onychophoran affinities of enigmatic metazoans. Nature, 1991, 351: 225–228CrossRefGoogle Scholar
  5. 5.
    Ramsköld L. Homologies in Cambrian Onychophora. Lethaia, 1992, 25: 443–460CrossRefGoogle Scholar
  6. 6.
    Chen J Y, Zhou G Q, Ramsköld, L. A new Early Cambrian onychophoran-like animal, Paucipodia gen. nov., from the Chengjiang fauna, China. Trans R Soc Edinb, Earth Sci, 1994, 85: 275–282Google Scholar
  7. 7.
    Hou X G, Bergström, J. Cambrian lobopodians—Ancestors of extant onychophorans? Zool J Linn Soc, 1995, 114: 3–19CrossRefGoogle Scholar
  8. 8.
    Budd G E, Peel J S. A new xenusiid lobopod from the Early Cambrian Sirius Passet fauna of north Greenland. Palaeontology, 1998, 41: 1201–1213Google Scholar
  9. 9.
    Ramsköld L, Chen J Y. Cambrian lobopodians: morphology and phylogeny. In: Edgecombe G D, ed. Arthropod Fossils and Phylogeny. New York: Columbia University Press, 1998. 107–150Google Scholar
  10. 10.
    Maas A, Waloszek D. Cambrian derivatives of the early arthropod stem lineage, pentastomids, tardigrades and lobopodians—an ‘Orsten’ perspective. Zool Anz, 2001, 240: 449–457CrossRefGoogle Scholar
  11. 11.
    Monge-Nájera J, Hou X G. Disparity, decimation and the Cambrian ‘explosion’: comparison of early Cambrian and present faunal communities with emphasis on velvet worms (Onychophora). Rev Biol Trop, 2002, 48: 333–351Google Scholar
  12. 12.
    Bergström J, Hou X G. Cambrian Onychophora or xenusians. Zool Anz, 2001, 240: 237–245CrossRefGoogle Scholar
  13. 13.
    Dzik J. Early Cambrian lobopodian sclerites and associated fossils from Kazakhstan. Palaeontology, 2003, 46: 93–112CrossRefGoogle Scholar
  14. 14.
    Bergström J, Hou X G. Chengjiang arthropods and their bearing on early arthropod evolution. In: Edgecombe G D, ed. Arthropod Fossils and phylogeny. New York: Columbia Univ Press, 1998. 151–184Google Scholar
  15. 15.
    Whittington H B. The lobopod animal Aysheaia pedunculata Walcott, Middle Cambrian, Burgess Shale, British Columbia. Phil Trans R Soc London, B, 1978, 284: 165–197CrossRefGoogle Scholar
  16. 16.
    Hou X G, Aldridge R J, Bergström J, et al. The Cambrian fossils of Chengjiang, China—The Flowering of Early Animal Life. Malden: Blackwell, 2004Google Scholar
  17. 17.
    Liu J, Shu D G, Han J, et al. A large xenusiid lobopod with complex appendages from the Lower Cambrian Chengjiang Lagerstätte. Acta Pal Pol, 2006, 51: 215–222Google Scholar
  18. 18.
    Waloszek D. The ‘Orsten’ window—a three-dimensionally preserved Upper Cambrian meiofauna and its contribution to the understanding of the evolution of Arthropoda. Pal Res, 2003, 7: 71–88CrossRefGoogle Scholar
  19. 19.
    Mass A, Braun A, Dong X P, et al. The ‘Orsten’—More than a Cambrian Konservat-Lagerstätte yielding exceptional preservation. Palaeoworld, 2006, 15: 266–282CrossRefGoogle Scholar
  20. 20.
    Storch V, Ruhberg H. Onychophora. In: Harrison F W, Rice M E, eds. Microscopic Anatomy of Invertebrates. New York: Wiley, 1993. 11–56Google Scholar
  21. 21.
    Dzik J, Krumbiegel G. The oldest ‘onychophoran’ Xenusion: a link connecting phyla? Lethaia, 1989, 22: 169–181CrossRefGoogle Scholar
  22. 22.
    Conway Morris S. A new Metazoan from the Cambrian Burgess Shale of British Columbia. Palaeontology, 1977, 20: 623–640Google Scholar
  23. 23.
    Liu J, Shu D G, Han J, et al. A rare lobopod with well-preserved eyes from Chengjiang Lagerstätte and its implications for origin of arthropods. Chin Sci Bull, 2004, 49(9): 1063–1071CrossRefGoogle Scholar
  24. 24.
    Kristensen R M. Sense Organs of Two Marine Arthrotardigrades (Heterotardigrada, Tardigrada). Acta Zool, 1981, 62: 27–40CrossRefGoogle Scholar
  25. 25.
    Kristensen R M, Higgins R P. Revision of Styraconyx (Tardigrada: Halechiniscidae), with Description of Two New Species from Disko Bay, West Greenland. Smith Contr Zool, 1984, 391: 1–40Google Scholar
  26. 26.
    Mayer G. Origin and differentiation of nephridia provide no support for the Articulata. Zoomorphology, 2006, 125: 1–12CrossRefGoogle Scholar
  27. 27.
    Budd G E. Why are arthropods segmented? Evol Dev, 2001, 3: 332–342CrossRefGoogle Scholar
  28. 28.
    Walker M H, Tait N N. Studies of embryonic development and the reproductive cycle in ovoviviparous Australian Onychophora (Peripatopsidae). J Zool, 2004, 264: 333–354CrossRefGoogle Scholar
  29. 29.
    Bertolani R, Grimaldi De Zio S, D’Addabbo Gallo M, et al. Postembryonic development in heterotardigrades. Monitore Zoologico Italiano (N.S.), 1984, 18: 307–320Google Scholar
  30. 30.
    Walossek D, Müller K J. Upper Cambrian stem-lineage crustaceans and their bearing upon the monophyletic origin of Crustacea and the position of Agnostus. Lethaia, 1990, 23: 409–427CrossRefGoogle Scholar

Copyright information

© Science in China Press 2007

Authors and Affiliations

  • Andreas Maas
    • 1
  • Georg Mayer
    • 2
  • Reinhardt M. Kristensen
    • 3
  • Dieter Waloszek
    • 1
  1. 1.Section for Biosystematic DocumentationUniversity of UlmUlmGermany
  2. 2.Department of Anatomy and Cell BiologyUniversity of MelbourneVictoriaAustralia
  3. 3.Zoological MuseumUniversity of CopenhagenCopenhagenDenmark

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