MooseRiver81 Posted June 28, 2016 Author Share Posted June 28, 2016 This is what Paul Copper replied, Interesting photos you sent of this mysterious 'fossil'. Without seeing it firsthand, image 3 seems to suggest it is a favositid tabulate coral base, with the core of the fossil having grown around a soft tubular organism in the centre.. The only way to make sure is to cut it in half vertically using a diamond saw...I presume the structure is calcitic? A bit of acetic (strong vinegar) or hydrochloric acid would make it fizz. If there is no internal structure to be seen in the cut section, this could be a concretion of sorts: it is remarkably circular at the base.... a concretion like that would probably be made of pyrite.. Around Kettle Point, Lake Huron, the Famennian (Late Devonian) Kettle Point shale has bulbous concretions of pyrite, or iron carbonate but many of those are huge, a meter or so in diameter.. Best wishes Paul Link to comment Share on other sites More sharing options...
MooseRiver81 Posted June 28, 2016 Author Share Posted June 28, 2016 Here's what another Paul said from Kansas, Dear Thomas My considered judgement about this is that it is an algal encrustation around the base of a plant stem (small tree trunk). I have seen similar in the Mesozoic of Europe. What happens is that plants (trees, reeds, etc.) are growing in a swamp rich in calcium carbonate. Algae grow around the base and precipitate calcium carbonate. As they grow, so they get larger and lay down layers of calcite. Eventually, the plant dies and the trunk rots, leaving a hole in the middle. So, the dome is the top, the flat base shows the concentric layers of radial calcite, and the hole is where the trunk was. A fossil alga, also know as a stromatolite. Hope this helps, Paul Paul Selden Director of the Paleontological Institute Gulf-Hedberg Distinguished Professor of Invertebrate Paleontology, Department of Geology University of Kansas, Lindley Hal Link to comment Share on other sites More sharing options...
CraigHyatt Posted June 28, 2016 Share Posted June 28, 2016 Base of a plant stem.... Wow! Pretty cool. Info: Craig Hyatt, retired software/electrical engineer Experience: Beginner, fossil hunting less than a year Location: Eagle Pass, TX USA on the border with Mexico, hot dry desert Formation: Escondido, Marine, Upper Cretaceous Materials: Sandstone, Mudstone, Shale, Chert, Chalk Typical: Thalassinoides, Sphenodiscus, Exogyra, Inoceramus Reference: http://txfossils.com/Txfossils.html Link to comment Share on other sites More sharing options...
doushantuo Posted June 28, 2016 Share Posted June 28, 2016 (edited) If it's a good example of bio-immuration,the inside might show the morphology of the stem it was epiphytic on Hundreds of epiphytic algae preserved like that? Edited June 28, 2016 by doushantuo Link to comment Share on other sites More sharing options...
CraigHyatt Posted June 28, 2016 Share Posted June 28, 2016 If it's a good example of bio-immuration,the inside might show the morphology of the stem it was epiphytic on Hundreds of epiphytic algae preserved like that? What's the usual size of this specimen as described by Prof. Selden? I could not find any images online. Info: Craig Hyatt, retired software/electrical engineer Experience: Beginner, fossil hunting less than a year Location: Eagle Pass, TX USA on the border with Mexico, hot dry desert Formation: Escondido, Marine, Upper Cretaceous Materials: Sandstone, Mudstone, Shale, Chert, Chalk Typical: Thalassinoides, Sphenodiscus, Exogyra, Inoceramus Reference: http://txfossils.com/Txfossils.html Link to comment Share on other sites More sharing options...
doushantuo Posted June 28, 2016 Share Posted June 28, 2016 As algal thalli go,that thing is huge 1 Link to comment Share on other sites More sharing options...
CraigHyatt Posted June 28, 2016 Share Posted June 28, 2016 (edited) As algal thalli go,that thing is hugeYeah. I was tactfully questioning the diagnosis. ;-)Edit: Thinking about how slowly the algal layers are added, it seems to me that for the center hole to remain open on a specimen that large, it would have to form around a piece of rebar. ;-) Also, it seems like a paleobotanist or paleontologist ought to be able to distinguish a sponge, coral, or stromatolite pretty definitively. Edited June 28, 2016 by CraigHyatt Info: Craig Hyatt, retired software/electrical engineer Experience: Beginner, fossil hunting less than a year Location: Eagle Pass, TX USA on the border with Mexico, hot dry desert Formation: Escondido, Marine, Upper Cretaceous Materials: Sandstone, Mudstone, Shale, Chert, Chalk Typical: Thalassinoides, Sphenodiscus, Exogyra, Inoceramus Reference: http://txfossils.com/Txfossils.html Link to comment Share on other sites More sharing options...
doushantuo Posted June 28, 2016 Share Posted June 28, 2016 (edited) I can understand somebody's reluctance to do so,but you have to damage a fossil like that,get some thin sections .i think a photosynthesizer in the photic zone needs a different shape to maximally photosynthesize Chaetetid? Edited June 28, 2016 by doushantuo 1 Link to comment Share on other sites More sharing options...
Rockwood Posted June 29, 2016 Share Posted June 29, 2016 Someone on here once (probably several people often) said 'go with the local'. When presented with an imperfect image there is a strong tendency to assign it to the mental image that is the most familiar to begin with. 1 Link to comment Share on other sites More sharing options...
MooseRiver81 Posted June 29, 2016 Author Share Posted June 29, 2016 There are hundreds on these around. All uniform in characteristics such as the hole, shape and dimensions. They vary from 18-28cm in diameter. I would like to get a positive ID but I think it needs to be analyzed. Even if it needs to be destroyed by slicing it up. Like I said, there are hundreds in the area. I don't think the professional diagnosis is right. But that's just my opinion and I'm not a professional. Link to comment Share on other sites More sharing options...
CraigHyatt Posted June 29, 2016 Share Posted June 29, 2016 Man, in that case, grab one and smash it with a hammer. Let's see what the innards look like. :-) 1 Info: Craig Hyatt, retired software/electrical engineer Experience: Beginner, fossil hunting less than a year Location: Eagle Pass, TX USA on the border with Mexico, hot dry desert Formation: Escondido, Marine, Upper Cretaceous Materials: Sandstone, Mudstone, Shale, Chert, Chalk Typical: Thalassinoides, Sphenodiscus, Exogyra, Inoceramus Reference: http://txfossils.com/Txfossils.html Link to comment Share on other sites More sharing options...
Al Dente Posted June 29, 2016 Share Posted June 29, 2016 Close up photos of the bottom and sides would really help in the identification of these. Much easier than slicing them up. 1 Link to comment Share on other sites More sharing options...
CraigHyatt Posted June 29, 2016 Share Posted June 29, 2016 Close up photos of the bottom and sides would really help in the identification of these. Much easier than slicing them up. Where's the fun in that? :-D Info: Craig Hyatt, retired software/electrical engineer Experience: Beginner, fossil hunting less than a year Location: Eagle Pass, TX USA on the border with Mexico, hot dry desert Formation: Escondido, Marine, Upper Cretaceous Materials: Sandstone, Mudstone, Shale, Chert, Chalk Typical: Thalassinoides, Sphenodiscus, Exogyra, Inoceramus Reference: http://txfossils.com/Txfossils.html Link to comment Share on other sites More sharing options...
tmaier Posted June 30, 2016 Share Posted June 30, 2016 I don't see a problem with dissecting a few, given that there are so many. I would microscopically look at the surface inside and out, and also look at the cross section of the wall to look for structures. 1 Link to comment Share on other sites More sharing options...
CraigHyatt Posted June 30, 2016 Share Posted June 30, 2016 (edited) There are hundreds on these around. All uniform in characteristics such as the hole, shape and dimensions. They vary from 18-28cm in diameter. I would like to get a positive ID but I think it needs to be analyzed. Even if it needs to be destroyed by slicing it up. Like I said, there are hundreds in the area. I don't think the professional diagnosis is right. But that's just my opinion and I'm not a professional.How are they distributed? Sort of randomly here and there, in groups, or in one large exclusive group? What else is around them? I mean, are they in the water, on a flat, level chalk bed, etc.?Personally, I'd like to see a couple of photos of the specimens in situ. That might be a good clue. Edit: Thinking outside the box, I wonder if these could be man made? Anchor? Fish net weight? Ballast? Beach umbrella base? Edited June 30, 2016 by CraigHyatt Info: Craig Hyatt, retired software/electrical engineer Experience: Beginner, fossil hunting less than a year Location: Eagle Pass, TX USA on the border with Mexico, hot dry desert Formation: Escondido, Marine, Upper Cretaceous Materials: Sandstone, Mudstone, Shale, Chert, Chalk Typical: Thalassinoides, Sphenodiscus, Exogyra, Inoceramus Reference: http://txfossils.com/Txfossils.html Link to comment Share on other sites More sharing options...
doushantuo Posted June 30, 2016 Share Posted June 30, 2016 (edited) sounds reasonable,reasonably sound reasoning. the bottom of the object is pretty flat,i noticed. If anthropogenic ,there might be clues(tool marks). Call me an idiot**,but i still think i see pores on the object.Just look closely. **of course I'm provoking all of you Someone should post a photograph of the objects in situ. Perhaps even use GIS to analyse spatial ditribution. We demand to know.Our curiosity has been piqued to the utmost ,and my nerves are taut as piano wires. This will discourage everybody from posting pictures of incertae sedis for years to come Edited June 30, 2016 by doushantuo 1 Link to comment Share on other sites More sharing options...
doushantuo Posted June 30, 2016 Share Posted June 30, 2016 (edited) If it's poriferan, desma's/scleres might be visible with the naked eye Edited June 30, 2016 by doushantuo Link to comment Share on other sites More sharing options...
CraigHyatt Posted June 30, 2016 Share Posted June 30, 2016 The bottom shot interests me the most. It has those uniform rings and radial lines. Almost like a tree trunk. Info: Craig Hyatt, retired software/electrical engineer Experience: Beginner, fossil hunting less than a year Location: Eagle Pass, TX USA on the border with Mexico, hot dry desert Formation: Escondido, Marine, Upper Cretaceous Materials: Sandstone, Mudstone, Shale, Chert, Chalk Typical: Thalassinoides, Sphenodiscus, Exogyra, Inoceramus Reference: http://txfossils.com/Txfossils.html Link to comment Share on other sites More sharing options...
doushantuo Posted June 30, 2016 Share Posted June 30, 2016 (edited) those radial lines probably led someone to go for rugosan coral.However,I also seem to see some form of concentric lines and the central opening LOOKS to go al the way through Edited June 30, 2016 by doushantuo 1 Link to comment Share on other sites More sharing options...
doushantuo Posted June 30, 2016 Share Posted June 30, 2016 (edited) I wonder if an anthaspidellid sponge could grow to this size... eg Aulocopium,or Brevaspidella. Which would make these Paleozoic,BTW Edited June 30, 2016 by doushantuo Link to comment Share on other sites More sharing options...
CraigHyatt Posted June 30, 2016 Share Posted June 30, 2016 Here's one example with both radial lines and concentric rings. http://www.kgg.org.uk/dibunophylumh.html Info: Craig Hyatt, retired software/electrical engineer Experience: Beginner, fossil hunting less than a year Location: Eagle Pass, TX USA on the border with Mexico, hot dry desert Formation: Escondido, Marine, Upper Cretaceous Materials: Sandstone, Mudstone, Shale, Chert, Chalk Typical: Thalassinoides, Sphenodiscus, Exogyra, Inoceramus Reference: http://txfossils.com/Txfossils.html Link to comment Share on other sites More sharing options...
doushantuo Posted June 30, 2016 Share Posted June 30, 2016 (edited) that bulbous shape STILL doesn't shout "coral" to me. Edited June 30, 2016 by doushantuo Link to comment Share on other sites More sharing options...
MarcusFossils Posted June 30, 2016 Share Posted June 30, 2016 Here's a far-out idea...puffbal-like fungi fossil? The question is...why not puffbal-like fungi fossil A whole fossil pufball community! It does actually make some sense...the size, number, shape, rings at the bottom... Website: https://www.instagram.com/paleo_archives/ --------------------------------------------------------------------------- “It is by no means an irrational fancy that, in a future existence, we shall look upon what we think our present existence, as a dream.” ― Edgar Allan Poe Link to comment Share on other sites More sharing options...
doushantuo Posted June 30, 2016 Share Posted June 30, 2016 what have you been smoking? Link to comment Share on other sites More sharing options...
MarcusFossils Posted June 30, 2016 Share Posted June 30, 2016 (edited) what have you been smoking? Shhhh Fungi Edited June 30, 2016 by MarcusFossils Website: https://www.instagram.com/paleo_archives/ --------------------------------------------------------------------------- “It is by no means an irrational fancy that, in a future existence, we shall look upon what we think our present existence, as a dream.” ― Edgar Allan Poe Link to comment Share on other sites More sharing options...
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