Project 3716: L. Martins, C. Souto, M. Tavares. 2020. Exploring the macrostructural anatomy of dendrochirotid sea cucumber’s (Echinodermata) calcareous rings under micro‐computed tomography and its bearing on phylogeny. Journal of Anatomy. Early View:null.
Specimen: Parathyone braziliensis (MZUSP:1304)
View: Outer view of calcareous ring

Abstract

Despite descending from heavily calcified ancestors, the holothuroid skeleton is fully internal and composed of microscopic ossicles and a ring of plates bound by connective tissue, the calcareous ring. The calcareous ring exhibits a complex and poorly understood morphology; as a result, establishing unambiguous homology statements about its macrostructure has been challenging and phylogenetic studies have had to simplify this important structure. Here, we provide the first broad comparative study of Dendrochirotida calcareous rings using micro‐computed tomography (μCT). A detailed description of the three‐dimensional macrostructure of the calcareous ring of 10 sea cucumber species, including rare and type specimens, is presented. The structures observed were highly variable at the subfamily level, especially at the point of tissue attachment. The relationship between the calcareous ring and its associated organs, and their functional morphology are discussed. To aid future phylogenetic studies, we listed 22 characters and performed a preliminary cladistic analysis. The topology obtained supports the idea that the simple, cucumariid ring is ancestral to the mosaic‐like phyllophorid ring; however, it did not support the monophyly of the cucumariids. It also did not support the family Sclerodactylidae, which was described based on the ring morphology. Differently from the dermal ossicles, which are highly homoplastic, the general homoplasy index of the calcareous ring characters was relatively low. This result highlights the importance of this structure for phylogenetic inference. Unfortunately, time since collection, rough collection methods and fixation can damage the skeleton, and the calcareous ring is often overlooked in taxonomic descriptions. The data presented here will improve our understanding of holothuroid relationships and facilitate studies on holothuroid functional morphology and biomechanics.


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Article DOI: 10.1111/joa.13385

Project DOI: 10.7934/P3716, http://dx.doi.org/10.7934/P3716
This project containsMatrices
  • 21 Media
  • 1 Matrix
  • 14 Taxa
  • 10 Specimens
  • 22 Characters
Total size of project's media files: 30.88G

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Total scored cells: 263
Total media associated with cells: 0
Total labels associated with cell media: 0
Characters
Total characters: 22
Total characters with associated media: 0
Total characters with media with labels: 0
Total character states: 56
Total character states with associated media: 0
Total character states with media with labels:0
Total unordered/ordered characters:22/0
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MorphoBank Project 3716
  • Creation Date:
    23 April 2020
  • Publication Date:
    29 December 2020
  • Project views: 986

    Authors' Institutions

    • National Museum of Natural History, Smithsonian Institution

    • Universidade de Sao Paulo (USP, University of Sao Paulo)



    Members

    member name taxa specimens media media
    notes
    chars character
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    labels
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    (scored, NPA, "-")
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    Camilla Souto
    Project Administrator
    141021192200263
    (252, 0, 11)
    000
    Luciana Martins
    Full membership
    00000000
    (0, 0, 0)
    000


    Taxonomic Overview for Matrix 'M26955' (12 Taxa)

    taxon unscored
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    NPA
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    "-" cellscell images labels on
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    [1] Chiridota rotifera
    Last Modified in 10/01/20
    0191903002
    [2] Paracaudina chilensis
    Last Modified in 10/01/20
    0202002002
    [3] Thyonidium seguroensis
    Last Modified in 10/01/20
    0202002002
    [4] Parathyone braziliensis
    Last Modified in 10/01/20
    0202002002
    [5] Cucumaria solangeae
    Last Modified in 10/01/20
    0202002002
    [6] Euthyonidiella kyushuensis
    Last Modified in 10/01/20
    0222200002
    [7] Temparena chuni
    Last Modified in 10/01/20
    1212100002
    [8] Coronatum baiensis
    Last Modified in 10/01/20
    0222200002
    [9] Anthrochirus loui
    Last Modified in 10/01/20
    0222200002
    [10] Pentadactyla longidentis
    Last Modified in 10/01/20
    0222200002
    [11] Stolus cognatus
    Last Modified in 10/01/20
    0222200002
    [12] Thyone crassidisca
    Last Modified in 10/01/20
    0222200002


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    type number of views Individual items viewed (where applicable)
    Total project views986
    Project overview108
    Matrix views59Phylogeny calcareous ring Dendrochirotida (21 views); Matrix landing page (38 views);
    Taxon list135
    Media views393Media search (94 views); M692394 (15 views); M687540 (13 views); M692400 (15 views); M692402 (13 views); M692502 (13 views); M692503 (13 views); M692504 (14 views); M692505 (14 views); M692506 (15 views); M692507 (14 views); M692510 (16 views); M692511 (13 views); M692512 (16 views); M692513 (12 views); M692514 (14 views); M692516 (14 views); M692517 (14 views); M693892 (12 views); M693893 (16 views); M693895 (17 views); M693896 (16 views);
    Specimen list218
    Views for media list47
    Bibliography26




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