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I had posted this piece in General Fossil Discussion area since it had my first trilobite on it. Someone message me saying that they thought it may be an echinoderm. The person said “that looks like an echinoderm ("calcichordate")fragment. Possibly the M1-M4 of a stylophoran(marginale elements)” I thought it was a form of bryozoan. However, I do not know the Mississippian or any Carboniferous fossils very well. So I’m willing to admit complete ignorance. Can anyone ID it and educate me as what it is? I found it in Siloam Springs, Arkansas in an area which Mancos identified as the Pitkin Limestone, which is Mississippian. ROCKD ID’d the area as St. Joe’s limestone. This is the item in question. I can’t say that I have seen segmented Bryozoa. The segments aren’t uniform in size. Although, I’m not sure if the segments are endemic or an artifact of being broken. I believe they are breaks. It is about 1.25 inches long and 7 mm wide. Just a slightly zoomed in pic of the same thing. A pic of the end. This is is a pic of the back side of the other side of the plate and other end of it, where there is a cross section honeycomb looking view. Your thoughts and comments would would be greatly appreciated. Kim
Well, I found my very first trilobite!!! I just had to share my excitement with people who can appreciate hunting for something elusive and then finally finding it. With the family I get a polite “Oh, that’s nice.” I can actually tell it’s a trilobite. I’m pretty sure I’ve found pieces of others in the past, but they were so mangled it’s hard for me to be certain what I have. Anyway, I’m not sure if it is whole or not. I am still cleaning it up. Funny thing is I found it in my own home town of Siloam Springs, Arkansas of all places where I lived while in high school. My family still lives there. It was only about 1/2 mile from my parent’s house. Crazy. I found it on a micro hash plate of sorts next to Bryozoa that I had picked up from a new home construction site. I don’t know about anyone else, but hunting in the middle of a nice quiet little neighborhood feels a bit like dumpster diving. People watch and give you odd looks. I was looking at the Bryozoa with 10x magnification when I found the little trilobite. I absolutely was not expecting that. It’s so tiny I can barely see it with the 10x. LOL But hey a first trilobite is a first trilobite even if I can’t take pics of it and show it to anyone. It seems like the counter equivalent of a tall fish tale only it’s a microscopic trilobite tale. “It was this big/tiny . . .” I think there may be 2 others on the plate as well, but not quite as small. Not that you can see it, but it is a little white speck inside the red circle below. The Bryozoa thing is maybe 1.25 inches long and 7 mm wide. The little trilobite isn’t even 1 mm long. All I can see is the tale end. There are crinoid segments all over this piece too that are also microscopic. Some less than 1 mm. I found it in NW Arkansas in the Pitkin Limestone, St. Joe member possibly, which is Mississippian. The Bryozoan piece is actually much prettier than the pics portrays it to be. It’s all sparkly. It’s crystalized.
RTR227 posted a topic in Fossil IDThis is my first post in Fossil Forum...names PD, in the next couple of days I will do an introductory post in the "Introduction" section but I wanted to get started with one of my specimens that has brought me to a wall. Late Devonian - Early Carboniferous, loose find in a fossil contaminated area so identifying the exact formation it came from has been a bit difficult. Possibilities within a stones throw of find are Boone Formation, Penters Chert, Clifty Limestone, Chattanooga Shale and Pitkin Limestone. I have been calling this little guy Tholuslensia collisspongia ONLY until I can identify the actual genus and species. From my current research, I have an initial taxonomy as follows: Porifera | Demospongiae | Chaetetid | Poecilosclerida | AND THAT IS WHERE MY GIANT WALL BEGINS... As you might already be aware, Arkansas does not have a good public fossil record database (something that I am currently working on changing) and trying to identify this sponge down through family, genus and species has been like trying to find the pin cushion that the needle in the haystack came out of. The University of Arkansas focuses more on fossil fuels than actual fossils, they were quite friendly but unable to provide me with any assistance. Their Museum Collection is off limits to me because I am not a paleontologist, accredited institution or research facility. Even though I am not a paleontologist, I do believe myself capable of figuring this puzzle out. It is just one of many paleontology puzzles I am currently working on. I am not afraid of rabbit holes, big words or old paleontology text books so if you have any information or leads that can help me get past this "wall" then by all means, SHARE ;-). There is a possibility that it could have come out of the Ordovician period. The majority of exposure, sediment and specimens from this location are Devonian/Mississippian. There is one new exposure of Ordovician that has surfaced due to creek erosion. It rests below all other primary material and my collisspongia could have eroded out of that exposure based on sheer proximity to the specimens resting location. I have my doubts though because of the iron staining that has permeated the calcified sandstone.Based on the amount of orange tinting the outer surface displays, I would think that the specimen had to have eroded out and been sitting for some time now. New fractures from the Ordovician peek-a-boo seem to be lighter in color ranging from white to camel tan. This orange tint makes me believe that the Ordovician formation is not the host rock that produced my fossil. That being said, I am perfectly comfortable with the idea and most likely, the actuality of being completely and totally WRONG about everything. So long as I can get close to the truth, I am good with as many missteps as it will take. Thanks again for anything you have to offer and thank you for helping create this great resource and forum. Specifications: Length (Middle Lens Curve): 110 mm Width (Across Lens Curve): 100 mm Height (Stem to Top of Dome): 70mm Circumference (Lens Perimeter): 340 mm Substance: White chert, calcified sandstone, limestone present within folds and around bottom stem/base