MacKenzie Smith

  • 2 days, 7 hours ago
    Lee Cone and MacKenzie Smith are now friends
  • 2 days, 10 hours ago
    MacKenzie Smith replied to the topic Lycopod? in the forum What Is It?

    Yes, I was agreeing with the ID. I don’t know what’s common or not in that area, just that it would fit given the age.

  • 3 days, 8 hours ago
    MacKenzie Smith posted a new activity comment

    @linda-lewis@jbauer Yes, there are solitary scleractinians. I think the easiest way to tell them apart is to look at their septal symmetry (here is an example https://ucmp.berkeley.edu/cnidaria/anthozoamm.html). Rugose are bilateral and scleractinians have hexagonal symmetry. To me, the specimen looks more bilateral but that could be because of weathering on the specimen or the angle I’m looking at. @nathan-newell from your knowledge of the area, is it possible that this specimen was transported by a creek from an older site?

    • I was trying to remember the symmetry but I think it goes deeper into the pattern of septae too. There is something very different about rugose. There is also a pattern in the exterior growth that I don’t see here, but am not sure how to verbally define. Thanks for chiming in @mackenzie-smith! Always good to get another set of eyes on these =]

    • It’s possible, but I’d say it’s unlikely. Montross is right between the Rappahannock and Potomac rivers, both of which are pretty much all Cenozoic until 40-50 miles upstream. And neither river is a straight-shot to the ocean; the Potomac in particular has lots of snakey curves that I would think would catch fossils tumbling along in the current.

  • 3 days, 8 hours ago
    RICHARD LEE and MacKenzie Smith are now friends
  • 3 days, 14 hours ago
    MacKenzie Smith replied to the topic Lycopod? in the forum What Is It?

    @richard-lee That would be my guess too.

  • 3 days, 14 hours ago
    MacKenzie Smith replied to the topic araucarioxylon? in the forum What Is It?

    @richard-lee I believe this is one of those Lepidodendrons that crossed into the Triassic. Not too many of them. The diamond shaped leaf bases are what makes me think that and rule out araucarioxylon which I don’t believe has that external texture.

  • 4 days, 13 hours ago
    MacKenzie Smith posted a new activity comment

    Looks like the link doesn’t work, sorry!

  • 4 days, 13 hours ago
    MacKenzie Smith posted a new activity comment

    @scott-flamand@jbauer, yes this is a true fern. Traditionally it belongs would be classified as the leaf genus Pecopteris. Order Marattiales, family Marattiaceae. However, I think some species got taken out and now it is probably Alloiopteris winslovii in the order Zygopteridales. https://fieldguides.fieldmuseum.org/sites/…color…/534_usa-age_fossils.pdf

  • 4 days, 13 hours ago
    MacKenzie Smith posted a new activity comment

    @kristin-hsu@jbauer Yup. And the specific epithet is occidentalis.

  • 5 days, 2 hours ago
    MacKenzie Smith posted a new specimen in the group Vacation Explorers from the myFOSSIL app

    MacKenzie Smith has contributed a new specimen to myFOSSIL!

  • 5 days, 2 hours ago
    MacKenzie Smith posted a new activity comment

    Bivalve? Were cancerid crabs a thing back then?

  • 6 days, 12 hours ago
    MacKenzie Smith posted a new activity comment

    Hi @jami-williams! @jbauer is correct, this is from the genus Metasequoia. The species is M. occidentalis. Oregon also has M. foxii which has longer leaflets. The shale is from the Big Basin Member of the John Day Formation which is early Oligocene (Rupelian), 33 Ma. Also for future reference, when imaging a fossil preserved in shale you can just image the sides that have a fossil since that has what is interesting. Of course if you want to verify if there is something or nothing on the other side you can post that as well. The three view points is used for specimens that have 3D preservation like some shells and bones.

  • 6 days, 13 hours ago
    MacKenzie Smith posted a new activity comment

    @jbauer Wood is good. It’d be hard to get any further in classification without doing sections or peels. Especially in the Carboniferous where we have club mosses, horsetails, seed ferns and conifers all producing wood. From the Jurassic forward you can at least say they are all seed plants but wood was in a bunch of different groups in the Late Paleozoic.

  • 6 days, 13 hours ago
    MacKenzie Smith posted a new activity comment

    Hi @jeff-nolder! I just want to confirm the orientation of the synangium (pollen bearing structure) in the matrix. It’s sort of on its side with the cup facing us and the attachment pointing away correct? (I am also tagging @jbauer to keep her in the loop of correspondence.)

  • 1 week ago
    MacKenzie Smith posted a new activity comment

    @jbauer@fred-anfilofieff I agree that it’s some sort of duck ulna. I don’t know if one can say mallard specifically but then again, I don’t know too much about duck osteology.

  • 1 week ago
    MacKenzie Smith posted a new activity comment

    @jbauer Nope, nothing else for me to add. Looks good! Just needs the taxonomy filled out. The lateral and medial condyles look a little more pronounced on this specimen than modern muskrats but idk how much variability is in the condyles.

  • 1 week ago
    MacKenzie Smith posted a new activity comment

    @jbauer@cathy-young Ah, sorry. I made the same mistake too.

  • 1 week ago
    MacKenzie Smith posted a new activity comment

    @cathy-young and @jbauer Very possible though I don’t recognize it immediately. Also perhaps a dermal ossicle? The rough surface on that one side reminds me of the attachment side for a dermal ossicle.

  • 1 week ago
    MacKenzie Smith posted a new activity comment

    @aubrey-miller@jbauer I think it’s coral too but I don’t think it’s Acropora. I’ve worked with modern Acropora from the Maldives and what really defines that genus are large, distinct corallites (calcified tubes where the polyp is) which I do not see evidence of in this specimen. While this genus is notorious for taking on different growth forms depending on its environment I believe the corallite part is constant.

  • 1 week ago
    MacKenzie Smith posted a new activity comment

    @jbauer Sadly, no ideas this time. I know very, very little on sponges XD

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