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  • Inoceramus Clam


    Images:

    davidcpowers
    • Specimen was collected on Oct 13, 2018. The location is Cedar Creek. It is 7 miles south of Glendive. The area is Pierre Shale. The specimen was in a concretion.

    Taxonomy

    Kingdom: Animalia
    Phylum: Mollusca
    Class: Bivalvia
    Order: Praecardioida
    Family: Inoceramidae
    Genus: Inoceramus
    Species: Inoceramus sp.
    Author Citation Sowerby 1814

    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: 10/13/2018
    Acquired by: Field Collection

    Dimensions

    Width: 4cm
    Height: 4cm

    Location

    Cedar Creek
    Glendive
    Montana
    United States

    Comments

    Specimen was collected on Oct 13, 2018. The location is Cedar Creek. It is 7 miles south of Glendive. The area is Pierre Shale. The specimen was in a concretion.



    User Feedback


    Zenmaster6

    Posted · Report

    Hey, I don't wanna be that guy, but don't bivalves have equal symmetry on the ends, and brachiopods have one edge hanging over the other like the one in the picture? 

    inoceramus-clam-a1.jpg.d9c22329991f4027a8233f603d693692.jpg

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    davidcpowers

    Posted · Report

    Hi Zenmaster6

    Hey, I don't wanna be that guy, but don't bivalves have equal symmetry on the ends, and brachiopods have one edge hanging over the other like the one in the picture? 

    5 hours ago, Zenmaster6 said:

    Hey, I don't wanna be that guy, but don't bivalves have equal symmetry on the ends, and brachiopods have one edge hanging over the other like the one in the picture? 

    inoceramus-clam-a1.jpg.d9c22329991f4027a8233f603d693692.jpg

    The photo is the hing line for this type of clam and is also the line of symmetry between both halves. While symmetry is not perfect it is there.

    Brachiopods have a different symmetry see this link below. Symmetry for brachiopods cuts both shells in half with more or less mirrored right and left sides.

     

    Here is a PDF link that gives details  about  Inoceramus  clams and a bit about their morphology. I am using this paper because of the detialed information

     

    https://www.researchgate.net/publication/286250061

    Palaeontology and biostratigraphy of the Middle-Upper Coniacian and
    Santonian inoceramids of the US Western Interior

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    DPS Ammonite

    Posted · Report

    On 2/6/2019 at 11:04 AM, Zenmaster6 said:

    Hey, I don't wanna be that guy, but don't bivalves have equal symmetry on the ends, and brachiopods have one edge hanging over the other like the one in the picture? 

    inoceramus-clam-a1.jpg.d9c22329991f4027a8233f603d693692.jpg

    The two valves have shifted relative to each other so that the beaks no longer meet. See another photo to see the shift:

    174F51FD-765C-4443-A7A8-2F6407F451ED.jpeg

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    Zenmaster6

    Posted · Report

    Hey, So I have this shelled creature I found in a mountain which used to be an Eocene shallow ocean. The end is very non-symmetrical with the other side in the last photo. People keep telling me this is a bivalve but online it looks like a brachiopod. 

    51508107_724003917996716_822729852023996416_n.jpg

    51745026_852718038232071_8795855759624634368_n.jpg

    51759851_373929866723315_2106938787358572544_n.jpg

    brachiopods_versus_bivalves_illustrated1_t-14562D91547566A19CC.jpg

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    Zenmaster6

    Posted · Report

    I also agree it is a bivalve because the lines go around the shell rather than vertical to the back but it looks like a brachiopod.
     

    I just realized he got his bivalve from cedar creek Montana.
    I found the one above at cedar creek Washington.

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    davidcpowers

    Posted · Report

    Zenmaster6 yours are brachiopods. Dorsa valvel and ventral valve do not mirror each other. Line of symmetry is down through center of both shells. As seen in example 2 c+d

    While the two valves of my clam were not completely in line  they have the symmetry as seen in example 1 A B of your diagram.

     

    You can not go by the over hang of the beak or pedicle alone. It is best to look at the entire fossil or as much of the fossil as you have. 

     

    Your question is a good one.

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