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  • Plumaster ophiuroides


    Images:

    TqB
    • Fossil of the Month, January 2015.

      Prepping details here: Jan 2015 finds of the month

       

      A partial, extremely rare, many armed starfish, the genus was assigned to a new family Plumasteridae in 2011: 

      A. S. Gale. 2011. Asteroidea (Echinodermata) from the Oxfordian (Late Jurassic) of Savigna, Départment du Jura, France. Swiss Journal of Palaeontology130:69-89

       

      This is from the same area and formation as the holotype of its species.

       

      The distinctive ossicles are common as disarticulated elements in sieved samples from Pliensbachian to Oxfordian.

       

      Excerpt from the above paper:

      Family Plumasteridae nov.

      Diagnosis: Multiarmed (12–22 arms) asteroids with broad adambulacrals which occupy the entire actinal sur- face of the arm and V distally: adambulacrals concavo- convex, 5–8 specialised interlocking articulation ridges and grooves articulate with ridges on adjacent adambulacral (modified ada2-3); abactinal ossicles with numerous lateral projections and embayments, and each carries a central large convex boss with which long, glassy, ridged spines articulate.

      Type genus: Plumaster Wright 1863, is the only genus included. It ranges from the Pliensbachian to the Oxfordian.

      Discussion: The Plumasteridae is established for the distinctive multiarmed genus Plumaster. This is distinguished from other multiarmed spinulosans such as solas- terids by the unusual boss-like spine articulations of the abactinal ossicles, and the highly modified adambulacral ossicles, which articulate by means of ridges and grooves. 

    Taxonomy

    Plumasterid sun star

    Kingdom: Animalia
    Phylum: Echinodermata
    Class: Asteroidea
    Order: Spinulosida
    Family: Plumasteridae
    Genus: Plumaster
    Species: P. ophiuroides
    Author Citation Wright, 1861

    Geological Time Scale

    Era: Mesozoic
    Period: Jurassic
    Epoch: Early
    International Age: Upper Pliensbachian

    Stratigraphy

    Lias Group
    Staithes Sandstone Formation

    Biostratigraphy

    Davoei Zone

    Provenance

    Collector: self
    Date Collected: 11/01/2011
    Acquired by: Field Collection

    Dimensions

    Width: 8.5cm
    Diameter: 11 (estimated complete specimen)cm

    Location

    North Yorkshire coast
    North Yorkshire County
    North east
    England

    Comments

    Fossil of the Month, January 2015.

    Prepping details here: Jan 2015 finds of the month

     

    A partial, extremely rare, many armed starfish, the genus was assigned to a new family Plumasteridae in 2011: 

    A. S. Gale. 2011. Asteroidea (Echinodermata) from the Oxfordian (Late Jurassic) of Savigna, Départment du Jura, France. Swiss Journal of Palaeontology130:69-89

     

    This is from the same area and formation as the holotype of its species.

     

    The distinctive ossicles are common as disarticulated elements in sieved samples from Pliensbachian to Oxfordian.

     

    Excerpt from the above paper:

    Family Plumasteridae nov.

    Diagnosis: Multiarmed (12–22 arms) asteroids with broad adambulacrals which occupy the entire actinal sur- face of the arm and V distally: adambulacrals concavo- convex, 5–8 specialised interlocking articulation ridges and grooves articulate with ridges on adjacent adambulacral (modified ada2-3); abactinal ossicles with numerous lateral projections and embayments, and each carries a central large convex boss with which long, glassy, ridged spines articulate.

    Type genus: Plumaster Wright 1863, is the only genus included. It ranges from the Pliensbachian to the Oxfordian.

    Discussion: The Plumasteridae is established for the distinctive multiarmed genus Plumaster. This is distinguished from other multiarmed spinulosans such as solas- terids by the unusual boss-like spine articulations of the abactinal ossicles, and the highly modified adambulacral ossicles, which articulate by means of ridges and grooves. 



    User Feedback


    jewelonly

    Posted · Report

    This is simply stunning, Tarquin! The close up makes it appear almost ephemeral.

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    You even have pictures of the tools use to prep this thing.  Nice.  Most folks never do that.

     

    Ron

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    KCMOfossil

    Posted · Report

    Fascinating!  And the hours spent prepping gave a wonderful result.

     

    Russ

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    @RJB @KCMOfossil Thanks for the comments! It was a pleasure to prep, would love to find another one. (Actually, I did but it was largely worn away by the sea. Hope they come in threes. :))

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    doushantuo

    Posted · Report

    I think you have to stop posting only marginally interesting echinoderms,Tarq;).

    My optic nerves have served me a legal notice:Either I stop looking at anything you post,or they are going to sue me for

    every penny i've got.

     

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