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Is it malleable? Any other ideas of what it could be, anyone?
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I don't think it looks like either. Looks like ceramic or plastic or something. If you hold a match up to it and it melts, its plastic
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Thanks to @ynot for providing us with this brain teaser.
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Thanks @MarcoSr if there was an extremely informative button I would click that. Is it true that symphyseal teeth are not lost or replaced like other files? This is usually a claim for rarity of symphyseal teeth.
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This clam is a common find in the Yorktown Formation bluff banks of the Tar River. It is often found in association with Echphora's. Many of these clams are "double valvers" but often break upon handling.
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The terminology used for the teeth in the symphysis area of a shark jaw has not been standardized. Different researchers use different terminology for the same tooth positions. The extant Hemipristis elongatus have both upper jaw and lower jaw symphyseal and medial teeth files in the convention that I use. The below pictures are from one of the jaws in my collection. Hemipristis elongatus (Snaggletooth Shark) Upper jaw symphysis showing two files of symphyseal teeth (blue) and one file of medial teeth (red): Hemipristis elongatus (Snaggletooth Shark) Lower jaw symphysis showing two files of symphyseal teeth (blue) and one file of medial teeth (red). Note a partial separation of the lower jaw at the symphysis moved the teeth relative to each other and made it very difficult to show them: l and medial teeth files. The tooth in this post is definitely not a symphyseal tooth. There isn't standard agreement among researchers on which shark teeth positions are laterals and which are posteriors for most shark species. Where the change occurs in a shark jaw can be quite arbitrary depending on the researcher. For many shark families that terminology doesn't even make sense because there is not enough tooth feature difference. Marco Sr.
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This is a very interesting and informative thread. Leah
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I would suggest prepping and clean these, especially the first one. It looks like it has a nice defined fossil plane that should be easy to prep away. I see fossils in both.
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As @ynot said Very unlikely. The conditions necessary for the formation of some agates (heat) may destroy more delicate fossils like insects. I know of some insect fossils that have been replaced by silicates, but I think carnelian would form in conditions with some heat and pressure. We have been discussing something along these lines here:
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Self collected from a bluff along the Tar River upstream of Tarboro N.C. This is a fairly common oyster in this deposit, but most are extremely brittle and crumble upon touching. Still looking for my first complete (double valve) specimen.
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The top image could show plant material. I'm not 100% sure that this isn't bone from this image. The orange but to the right looks like a fish scale. I would prep these more with a needle. Looks like soft mudstone? The bottom image may also be plant material. First I though bone but we would need it cleaned up a bit and a clearer close up. It is most likely carbonised plant material with some sort of mineral coating (calcite?).
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Even the second one ? Could have sworn it looks like some sort of plant
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I am not seeing anything that is identifiable as a fossil in these pictures. It looks like mineral stain and fracture marks.
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Nice. Looks like it could be a Mammites sp. ammonite.
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Here are two fossils I found today , they are from Southern California marine Miocene rocks. The one with the spike looking thing is around an inch (you can see my leg for scale reference). Absolutely no idea what the first is, the second looks like some sort of plant or arthropod. Thanks in advance
