An armoured Cambrian lobopodian from China with arthropod-like appendages
Liu, J.; Steiner, M.; Dunlop, A.; Keupp, H.; Shu, D.; Ou, Q.; Han, J.; Zhang, Z.; Zhang, X. (2011). An armoured Cambrian lobopodian from China with arthropod-like appendages. Nature (Lond.) 470(7335): 526-530. https://dx.doi.org/10.1038/nature09704
In: Nature: International Weekly Journal of Science. Nature Publishing Group: London. ISSN 0028-0836; e-ISSN 1476-4687, more
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| Keywords |
Biological phenomena > Evolution
Biology > Zoology
Palaeo studies > Palaeontology
Marine/Coastal |
| Authors | | Top |
- Liu, J.
- Steiner, M.
- Dunlop, A.
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- Han, J.
- Zhang, Z.
- Zhang, X.
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| Abstract |
Cambrian fossil Lagerstatten preserving soft-bodied organisms have contributed much towards our understanding of metazoan origins(1-3). Lobopodians are a particularly interesting group that diversified and flourished in the Cambrian seas. Resembling 'worms with legs', they have long attracted much attention in that they may have given rise to both Onychophora (velvet worms)(4-6) and Tardigrada (water bears)(7,8), as well as to arthropods in general(9-12). Here we describe Diania cactiformis gen. et sp. nov. as an 'armoured' lobopodian from the Chengjiang fossil Lagerstatte (Cambrian Stage 3), Yunnan, southwestern China. Although sharing features with other typical lobopodians, it is remarkable for possessing robust and probably sclerotized appendages, with what appear to be articulated elements. In terms of limb morphology it is therefore closer to the arthropod condition, to our knowledge, than any lobopodian recorded until now. Phylogenetic analysis recovers it in a derived position, close to Arthropoda; thus, it seems to belong to a grade of organization close to the point of becoming a true arthropod. Further, D. cactiformis could imply that arthropodization (sclerotization of the limbs) preceded arthrodization (sclerotization of the body). Comparing our fossils with other lobopodian appendage morphologies-see Kerygmachela(9,10), Jianshanopodia(13) and Megadictyon(12)-reinforces the hypothesis that the group as a whole is paraphyletic, with different taxa expressing different grades of arthropodization. |
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