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    davidcpowers
    • I was seven miles south of Glendive; Montana on October 12, 2018; time 1400; exploring a drainage cut into the Pierre Shale Formation while looking for concretions. This scaphites was partly exposed on the surface of a concretion. Later, I removed most of the surrounding matrix. 

    Taxonomy

    Ammonite

    Kingdom: Animalia
    Phylum: Mollusca
    Class: Cephalopoda
    Order: Ammonitida
    Family: Scaphitidae
    Genus: Hoploscaphites
    Species: Hoploscaphites spedeni

    Geological Time Scale

    Eon: Phanerozoic
    Era: Mesozoic
    Period: Cretaceous
    Epoch: Late
    International Age: Campanian

    Stratigraphy

    Pierre Shale Formation

    Provenance

    Collector: David C Powers
    Date Collected: 10/12/2018
    Acquired by: Field Collection

    Dimensions

    Blank: 5.5cm
    Width: 2.5cm
    Height: 5cm

    Location

    Cedar Creek
    Dawson
    Montana
    United States

    Comments

    I was seven miles south of Glendive; Montana on October 12, 2018; time 1400; exploring a drainage cut into the Pierre Shale Formation while looking for concretions. This scaphites was partly exposed on the surface of a concretion. Later, I removed most of the surrounding matrix. 



    User Feedback


    davidcpowers

    Posted · Report

    The area is mostly fissile shale with varying size concretions. These concretions appear to be made of the same minerals as the shale. (

    See the picture of a concretion and surrounding shale.)  All of the fossils I found were in concretions. 

     

    Here is a picture of the Hoploscaphite in the concretion. I used a diamond blade attached to a flex shaft Dremel and running water to cut away the surrounding matrix. Then I used a small diamond grinding bit and hand dental picks to remove the matrix off of the fossil.

     

     

    ammonite-in-concretion.jpg

    concretion.jpg

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