Texas Fossil Hound Posted October 22, 2014 Share Posted October 22, 2014 I found this cylindrical fossil while hunting at the Jacksboro, TX Pennsylvanian site with the DPS a few weeks ago. Not sure what it is, but leaning toward an orthoconic cephalopod (Thanks BobWill!). Anyone else have some insight? It is definitely not plant. It has a 1mm thick shell all the way around except where it has flaked off. The center is sediment and may have some extremely thin chambers, but it is hard to tell. I added some photos from the microscope. The fossil is round and does not appear to taper. It has a calcite-like buildup at one end. The break points in the shell do not appear to be original sections because there is some irregularity in them going around the diameter. Post what you have and lets see if we can figure this out. Go! "Silence is Golden, but duct tape is Silver." Link to comment Share on other sites More sharing options...
Texas Fossil Hound Posted October 22, 2014 Author Share Posted October 22, 2014 Here are a few more pics from the Microscope. Note the pic that shows some possible thin chambers - only 4mm apart, but appear at fairly regular intervals. Cephalopod? "Silence is Golden, but duct tape is Silver." Link to comment Share on other sites More sharing options...
Texas Fossil Hound Posted October 22, 2014 Author Share Posted October 22, 2014 A couple more... "Silence is Golden, but duct tape is Silver." Link to comment Share on other sites More sharing options...
BobWill Posted October 22, 2014 Share Posted October 22, 2014 Here's the best picture I can take until daylight. Link to comment Share on other sites More sharing options...
Roz Posted October 22, 2014 Share Posted October 22, 2014 Here is mine Welcome to the forum! Link to comment Share on other sites More sharing options...
Ptychodus04 Posted October 22, 2014 Share Posted October 22, 2014 Looks like a straight nautiloid to me. I don't have the reference in front of me but it looks very similar to one I collected in Bridgeport years ago. Regards, Kris Global Paleo Services, LLC https://globalpaleoservices.com http://instagram.com/globalpaleoservices http://instagram.com/kris.howe Link to comment Share on other sites More sharing options...
LanceH Posted October 22, 2014 Share Posted October 22, 2014 I went through the Invert Treatise and still haven't found anything that matches. Link to comment Share on other sites More sharing options...
Texas Fossil Hound Posted October 29, 2014 Author Share Posted October 29, 2014 I am leaning toward orthocone myself, but need better evidence of chambering. jon "Silence is Golden, but duct tape is Silver." Link to comment Share on other sites More sharing options...
Auspex Posted October 29, 2014 Share Posted October 29, 2014 Phragmocone, maybe? "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Highlander Posted October 29, 2014 Share Posted October 29, 2014 (edited) I dont thing that it is nautiloid. If you fossil have a cleavage, make please a photo. Many thinks can get esier, when we understand internal structure of the fossil. That transverse lines on your photo looks like similar of crinoide stem. Need a photo ftom another angle. Or may be it is a fragmocon fith part of a "residential chamber" of heteromorphous ammonoidea. But the distance between walls of chambers is too small. Edited October 29, 2014 by Highlander Link to comment Share on other sites More sharing options...
Roz Posted October 29, 2014 Share Posted October 29, 2014 Since Jon's example is nicer, I decided to open mine to see if it would be helpful to see inside. I also had 2 others from the past that I think are the same as Jon's and Bob's. If anyone thinks they are not the same material, I can delete the below images as I do not want to cause confusion. If you think they are the same, I will go ahead and open the others. The cracks look like fractures to me and not diagnostic. Welcome to the forum! Link to comment Share on other sites More sharing options...
howard_l Posted October 29, 2014 Share Posted October 29, 2014 Some of the pictures do resemble nautiloids but some are burrows. Keep looking for any sign of a siphuncle, you may have to break them open. If you can find that you know they are cephalopods. Howard_L http://triloman.wix.com/kentucky-fossils Link to comment Share on other sites More sharing options...
Rockwood Posted October 29, 2014 Share Posted October 29, 2014 It almost looks like the sediment filled it very slowly in layers. Could it be a worm tube that was buried slowly while still upright ? Link to comment Share on other sites More sharing options...
Roz Posted October 29, 2014 Share Posted October 29, 2014 I just don't know. I thought the one I opened looked like Jon's but if it isn't the same then my experiment wasn't much help. Welcome to the forum! Link to comment Share on other sites More sharing options...
rwise Posted October 29, 2014 Share Posted October 29, 2014 (edited) here are some from Jacksboro as well. Many have segmentation lines and the one below split along one of the lines to reveal the inside. The one with the ruler is a straight cephalopod. Don't know about the other, but they are numerous in the Jacksboro area..... Edited October 29, 2014 by rwise Thanks for your help in advance. Link to comment Share on other sites More sharing options...
howard_l Posted October 29, 2014 Share Posted October 29, 2014 I find burrows all the time that resemble a straight nautiloid shell. segmentation is not enough to identify one, unless it was just a living chamber a siphuncle is the best way to determine if it is truly a cephalopod. Howard_L http://triloman.wix.com/kentucky-fossils Link to comment Share on other sites More sharing options...
tmaier Posted October 29, 2014 Share Posted October 29, 2014 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 29, 2014 Share Posted October 29, 2014 (edited) Did scaphopods get that big there/then? If it's not a ceph or burrow, that would be my next guess, except that the first one seems to narrow then widen again, which would argue against any sort of orthocone/tusk shaped shell. I just can't tell for sure whether we're looking at shell material or 'slickensides' on some of those. Edited October 29, 2014 by Wrangellian Link to comment Share on other sites More sharing options...
Missourian Posted October 29, 2014 Share Posted October 29, 2014 Something akin to Artisia comes to mind, except for the thin shelly material. Context is critical. Link to comment Share on other sites More sharing options...
Herb Posted October 30, 2014 Share Posted October 30, 2014 my guess is cephalopod "Absence of evidence is not evidence of absence"_ Carl Sagen No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go. " I think, therefore I collect fossils." _ Me "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes "can't we all just get along?" Jack Nicholson from Mars Attacks Link to comment Share on other sites More sharing options...
BobWill Posted October 30, 2014 Share Posted October 30, 2014 All the scaphopods I've found there are much smaller. Also I wouldn't think a burrow or Artisia either one would have those ridges you see going down the length of these. Link to comment Share on other sites More sharing options...
BobWill Posted October 30, 2014 Share Posted October 30, 2014 I tried to saw one lengthwise like Roz and it broke. It looks like concentric layers on the end view at the break, like on a concretion. I'm drifting back to plant, maybe seed fern. Link to comment Share on other sites More sharing options...
tmaier Posted October 30, 2014 Share Posted October 30, 2014 This is a good one. So far, even the kingdom hasn't been nailed. :popcorn: :popcorn: :popcorn: Link to comment Share on other sites More sharing options...
Missourian Posted October 30, 2014 Share Posted October 30, 2014 Do any of the specimens shown here have any encrusting fossils on their surfaces? Context is critical. Link to comment Share on other sites More sharing options...
LanceH Posted October 30, 2014 Share Posted October 30, 2014 The "shell" is always disjointed, deformed or otherwise irregular. I'm not even sure if it's a "shell". Maybe it's some sort of calcium burrow lining secreted by giant worms or molluscs. Link to comment Share on other sites More sharing options...
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