Missourian Posted February 15, 2013 Author Share Posted February 15, 2013 It belongs to Calcarea or to Demospongia? Demospongiae, I believe. Context is critical. Link to comment Share on other sites More sharing options...
Missourian Posted February 19, 2013 Author Share Posted February 19, 2013 Cross sections of sponges in limestone Merriam Limestone, Pennsylvanian Johnson County, Kansas Girtyocoelia: Girtycoelia: Girtycoelia: Context is critical. Link to comment Share on other sites More sharing options...
Evgeny Kotelevsky Posted February 19, 2013 Share Posted February 19, 2013 Nice findings! You can get only imprints of Girtycoelia or complete specimen can also be found? http://evgenykotelevsky.wordpress.com Link to comment Share on other sites More sharing options...
Missourian Posted February 19, 2013 Author Share Posted February 19, 2013 Nice findings! You can get only imprints of Girtycoelia or complete specimen can also be found? Both can be found at the same site. The ones shown above are embedded in the top of the limestone. The sponges 'continue' into the shale above, where they can be picked up. Here are a few: Context is critical. Link to comment Share on other sites More sharing options...
Evgeny Kotelevsky Posted February 19, 2013 Share Posted February 19, 2013 Cross-section together with complete specimen are perfect for understanding Girtycoelia's structure and way of life )))) http://evgenykotelevsky.wordpress.com Link to comment Share on other sites More sharing options...
Wrangellian Posted February 19, 2013 Share Posted February 19, 2013 Yes, and it's hard (for me at least) to tell the difference between the two genera except by those cross-sections. Link to comment Share on other sites More sharing options...
Evgeny Kotelevsky Posted February 19, 2013 Share Posted February 19, 2013 (edited) Yes, and it's hard (for me at least) to tell the difference between the two genera except by those cross-sections. You can differ generas from each other by shape, sculpture of inner and outer surfaces and by type of dichotomy Edited February 19, 2013 by Evgeny Kotelevsky http://evgenykotelevsky.wordpress.com Link to comment Share on other sites More sharing options...
Missourian Posted February 19, 2013 Author Share Posted February 19, 2013 Also, Girtyocoelia has 'porthole' like openings at the middle of the lobes, while Girtycoelia has them near the junctures. Context is critical. Link to comment Share on other sites More sharing options...
Evgeny Kotelevsky Posted February 19, 2013 Share Posted February 19, 2013 Also, Girtyocoelia has 'porthole' like openings at the middle of the lobes, while Girtycoelia has them near the junctures. Location of osculum/osculums is also difference between generas http://evgenykotelevsky.wordpress.com Link to comment Share on other sites More sharing options...
Wrangellian Posted February 19, 2013 Share Posted February 19, 2013 Maybe I would learn to distinguish these features if I could collect them regularly myself, but not having that chance, they look very similar. Link to comment Share on other sites More sharing options...
Missourian Posted February 19, 2013 Author Share Posted February 19, 2013 I should start using Heterocoelia, the old name for Girtyocoelia. At least the names could be dissimilar. Context is critical. Link to comment Share on other sites More sharing options...
Evgeny Kotelevsky Posted February 19, 2013 Share Posted February 19, 2013 Difference is in one letter ))))))) http://evgenykotelevsky.wordpress.com Link to comment Share on other sites More sharing options...
Missourian Posted September 17, 2013 Author Share Posted September 17, 2013 (edited) 'Stings of pearls'.... Girtyocoelia sp. Bonner Springs Shale (or basal Plattsburg Formation), Pennsylvanian (Edit: It is actually the Hickory Creek Shale. The stratigraphy in this spot is quite unusual....) Wilson County, Kansas Edited September 20, 2013 by Missourian Context is critical. Link to comment Share on other sites More sharing options...
Evgeny Kotelevsky Posted September 17, 2013 Share Posted September 17, 2013 'Stings of pearls'.... Girtyocoelia sp. Bonner Springs Shale (or basal Plattsburg Formation), Pennsylvanian Wilson County, Kansas 3554-Wilson-Girtyocoelia-1.jpg 3565-Wilson-Girtyocoelia-3.jpg Wow! It's great! You're going to prep them out of matrix? http://evgenykotelevsky.wordpress.com Link to comment Share on other sites More sharing options...
Missourian Posted September 17, 2013 Author Share Posted September 17, 2013 Wow! It's great! You're going to prep them out of matrix? Probably not. They are in pretty tight. Context is critical. Link to comment Share on other sites More sharing options...
Ridgehiker Posted September 17, 2013 Share Posted September 17, 2013 Enjoying this thread and learning from it. I wonder how many times I've overlooked sponges by not looking at details. Curious....what other fauna do you most usually find with sponges? Corals? Crinoids? Bryozoa? I might not be recognizing sponge specimens either in the matrix or loose. Have seen isolated sponge spicules when viewing sediment under a microscope but not enough to know anything about them. Link to comment Share on other sites More sharing options...
Missourian Posted September 17, 2013 Author Share Posted September 17, 2013 Curious....what other fauna do you most usually find with sponges? Corals? Crinoids? Bryozoa? I might not be recognizing sponge specimens either in the matrix or loose. Around here, sponges are usually sparse, but they can be quite abundant locally. They tend to be numerous around algal reef mounds. Associated fossils usually include crinoids (especially Erisocrinus, it seems), bryozoans, brachiopods and algae. The invertebrate fossils other than the sponges tend to be smaller in size. Context is critical. Link to comment Share on other sites More sharing options...
Missourian Posted September 17, 2013 Author Share Posted September 17, 2013 I wonder how many times I've overlooked sponges by not looking at details. Sponges are commonly tubular in form and have 'casual' detailing, i.e. the pores aren't quite as sharp as those seen on bryozoans. Spotting sponges can be as much an art as a science. Context is critical. Link to comment Share on other sites More sharing options...
Wrangellian Posted September 19, 2013 Share Posted September 19, 2013 Those are great, Missourian! Northstar, I could have easily overlooked my sponges if I hadn't caught sight of the netlike spicule pattern (Hexactinellid) - Didn't know what they were at first: I also see various lumps and sticks and so on up there but I don't know if they are sponges if I don't see spicules (Could be calcareous algae.. still thinking about it) Link to comment Share on other sites More sharing options...
Evgeny Kotelevsky Posted September 19, 2013 Share Posted September 19, 2013 Those are great, Missourian! Northstar, I could have easily overlooked my sponges if I hadn't caught sight of the netlike spicule pattern (Hexactinellid) - Didn't know what they were at first: Tz93pos(1) sha.jpg I also see various lumps and sticks and so on up there but I don't know if they are sponges if I don't see spicules (Could be calcareous algae.. still thinking about it) I guess, it's a print of some Bryozoa http://evgenykotelevsky.wordpress.com Link to comment Share on other sites More sharing options...
Evgeny Kotelevsky Posted September 19, 2013 Share Posted September 19, 2013 Those are great, Missourian! Northstar, I could have easily overlooked my sponges if I hadn't caught sight of the netlike spicule pattern (Hexactinellid) - Didn't know what they were at first: Tz93pos(1) sha.jpg I also see various lumps and sticks and so on up there but I don't know if they are sponges if I don't see spicules (Could be calcareous algae.. still thinking about it) Some Bryozoa like this one http://evgenykotelevsky.wordpress.com Link to comment Share on other sites More sharing options...
Wrangellian Posted September 19, 2013 Share Posted September 19, 2013 I guess, it's a print of some Bryozoa I'm pretty sure it's this: Link to comment Share on other sites More sharing options...
Evgeny Kotelevsky Posted September 19, 2013 Share Posted September 19, 2013 I'm pretty sure it's this: Hormathospongia-page-shr.jpg May be you're right http://evgenykotelevsky.wordpress.com Link to comment Share on other sites More sharing options...
Missourian Posted September 21, 2013 Author Share Posted September 21, 2013 Some chaetetid sponges from the Coal City Limestone of Johnson County, Missouri.... The sponge colonies can be seen as gray areas in the outcrop: Two large mounds: A cross section shows growth lines and radiating tubes: This is the largest intact colony: It resembles a large loaf of bread, complete with cracked crust: Smooth areas are covered with pores: Context is critical. Link to comment Share on other sites More sharing options...
Missourian Posted September 21, 2013 Author Share Posted September 21, 2013 Growth lines: Chaetetid in matrix: Fresh break: Etched break: Attached Syringopora coral: Mineral concretions formed within the colonies in places: Context is critical. Link to comment Share on other sites More sharing options...
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