Kurufossils Posted November 25, 2020 Share Posted November 25, 2020 Found this piece on a walk near a Triassic outcrop in Pennsylvania, has a pretty exact visual similiarity to the wing rib of a Triassic reptile but is likely just some form of sedimentary trace. It would be great to get some more opinions on this piece to see if its worth holding onto or I would label it to be definitely sedimentary and rid of it, which I feel is the case. Link to comment Share on other sites More sharing options...
Kurufossils Posted November 26, 2020 Author Share Posted November 26, 2020 Here is some additional pictures with a comparison to an icarosaurus wing rib partial. Link to comment Share on other sites More sharing options...
Petalodus12 Posted November 26, 2020 Share Posted November 26, 2020 I’m no expert in Newark Supergroup material, but I’d hazard to guess that Icarosaurus material is quite rare (is the type specimen the only specimen known?). Simply due to the extreme rarity of the material I personally would assume it to be trace fossils. This isn’t based heavily on morphology and I have no field experience working with material from those deposits so I’d say wait for replies from other, more experienced members. Link to comment Share on other sites More sharing options...
hemipristis Posted November 26, 2020 Share Posted November 26, 2020 hello, I believe the specimen that you have represents an ichnofossil, either repichnia (locomotion trail) or pachichnia (feeding trace). The piece resembles the mudstones/shales common in the strata rather than the bone that you present in a later photo. Note the the trails consist of a paralleled pair lines, some of which overlap one another. The graphic that you included represents an illustration of the rib configuration of an Icarosaurus rather than the crenelations (wrinkles) on an individual rib, which is your last photo. 1 'Those who cannot remember the past are condemned to repeat it.' George Santayana Link to comment Share on other sites More sharing options...
Rockwood Posted November 26, 2020 Share Posted November 26, 2020 This looks more like an impression to me. For once, in the literal sense. I can't speculate further though. Link to comment Share on other sites More sharing options...
Pemphix Posted November 26, 2020 Share Posted November 26, 2020 Probably Swim Marks: http://www.palaeodiversity.org/pdf/08Suppl/12Palaeodiversity_SB_Hagdorn.pdf -> Pic. 12.9, p.274 or Scratch marks from small reptiles. 1 Link to comment Share on other sites More sharing options...
Rockwood Posted November 26, 2020 Share Posted November 26, 2020 Wouldn't the creature(s) have needed to swim by the same spot in multiple directions ? In the interval that was preserved, it would be busy little spot. Link to comment Share on other sites More sharing options...
Pemphix Posted November 26, 2020 Share Posted November 26, 2020 2 hours ago, Rockwood said: Wouldn't the creature(s) have needed to swim by the same spot in multiple directions ? In the interval that was preserved, it would be busy little spot. Fish has bilateral symetric means fins on both side, every move of a fin will cause a mark in the sediment. And yes, some of the fishes staying for some time on one spot. The attached picture in my last post shows a coelacanth swimming along short above the sediment, causing fin marks from the pectoral fins and the tail fin. Consider furthermore that it is not clarified, if all the marks are really on one sediment layer (milimeters can be million of years between..). And at least it could be a claw mark of a small reptile, too as i wrote. 2 Link to comment Share on other sites More sharing options...
Kurufossils Posted November 26, 2020 Author Share Posted November 26, 2020 Thanks for the insight I didn't even consider that fish would also be able to leave a trace with thier fins, I had a feeling this was a trace layer but I've never come across swimming traces like this yet so had to be sure, upon closer examination with this new info they remind me most of the fish traces from the swim marks publications than most lizard ones. Very cool and great to learn about these for the future. Having two gliding reptile wing rib bones wouldve been something but I'm happy to have my first trace like this one, thank you! Link to comment Share on other sites More sharing options...
Rockwood Posted November 26, 2020 Share Posted November 26, 2020 I'm coming around to the idea now. I think. It would be an inverted view with the darker layer likely representing the underwater surface at the time, or times ? Link to comment Share on other sites More sharing options...
Pemphix Posted November 28, 2020 Share Posted November 28, 2020 On 26.11.2020 at 2:40 PM, Rockwood said: I'm coming around to the idea now. I think. It would be an inverted view with the darker layer likely representing the underwater surface at the time, or times ? Yes, would be an "undertrack". Link to comment Share on other sites More sharing options...
Pemphix Posted November 28, 2020 Share Posted November 28, 2020 P.S.: Tracks are a possibility assuming that there's no bone material under the structure.. 1 Link to comment Share on other sites More sharing options...
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