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  • Maotianshania cylindrica


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    MarcusFossils
    • Recent phylogenetic analyses place this worm-like animal either within Nematomorpha or Priapulida. It is distinguished from Cricocosmia by it's much more slender appearance, as well as the absence of sclerites on its trunk. 

    Taxonomy

    Kingdom: Animalia
    Phylum: Nematomorpha or Priapulida
    Class: Palaeoscolecida
    Order: Incertae sedis
    Family: Maotianshaniidae
    Genus: Maotianshania
    Species: M. cylindrica
    Author Citation Sun and Huo, 1987

    Geological Time Scale

    Eon: Phanerozoic
    Era: Paleozoic
    Period: Cambrian
    Epoch: Early
    International Age: Age 3

    Stratigraphy

    Heilinpu Formation

    Provenance

    Acquired by: Purchase/Trade

    Dimensions

    Blank: ~2.5cm

    Location

    Chengjiang County
    Yunnan Province
    China

    Comments

    Recent phylogenetic analyses place this worm-like animal either within Nematomorpha or Priapulida. It is distinguished from Cricocosmia by it's much more slender appearance, as well as the absence of sclerites on its trunk. 



    User Feedback


    oilshale

    Posted · Report

    Cricocosmia (not Circocosmia, a very common misspelling!) and Maotianshania are really difficult to distinguish - the size is almost the same, but trunk ornamentation seems to be slightly different. I wouldn't dare to distinguish them without a very good microscope.
    Lit.:
    Han, J., Liu, J., Zhang, Z., Zhang, X., and Shu, D. 2007. Trunk ornament on the palaeoscolecid worms Cricocosmia and Tabelliscolex from the Early Cambrian Chengjiang deposits of China. Acta Palaeontologica Polonica 52 (2): 423–431.


    Excerpt:

    "Maotianshania cylindrica Sun and Hou, 1985 bears numerous irregularly arranged uniform trunk sclerites, SEM

    analysis revealing that each sclerite bears four nodes (Hu 2005); the trunk of Cricocosmia jinningensis Hou and Sun, 1988 is well known for bearing double rows of lateral conical sclerites, but little is yet know about the microstructure of these sclerites."

    5938b083eaeb0_CricocosmiaMaotianshania.JPG.2c50842c44a2d1e9761629d1568c83b1.JPG

    Figure 2 Representatives of Chengjiang priapulids. (a) Maotianshania cylindrica Sun & Hou, 1987; (b) Palaeoscolex sinensis Hou & Sun, 1988; (c)

    Cricocosmia jinningensis Hou & Sun, 1988;


     

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    MarcusFossils

    Posted · Report

    I must have read the correct spelling a hundred times and it never sunk in...Thank you for the correction! 

    They are indeed very difficult to distinguish, and my classification of this fossil may be wrong. I don't however see any "large paired sclerites along the trunk" (Hou et al, 2017).

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    MarcusFossils

    Posted · Report

    I've just re-read Hou et al 2017, and would add that Maotianshania has 3-4 annuli per millimeter, whereas Cricocosmia has nearly half that number, at 2-2.4 annuli per millimeter. I think it fair to classify this fossil at Maotianshania based on its higher annuli per millimeter density. 

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    oilshale

    Posted · Report

    Hou et al. 2017, the chapter "Priapulida and Relatives" in 'The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life, pp.114-137'? Didn't know the difference of annuli per millimeter. Helped me a lot.

    I knew, I should have bought this book...

    Thanks Marcus

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    MarcusFossils

    Posted · Report

    2 minutes ago, oilshale said:

    I knew, I should have bought this book...

     

    Just PM me your email address and I'll send it to you via WeShare :)

    -Marc 

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