JeanB Posted April 9, 2014 Share Posted April 9, 2014 (edited) Hi, I posted this a year ago, but it was left with no suggestion. It may not be a fossile, or it may be impossible to place an identification on it. Please allow me to try it once more. This rock (Trenton Group, ordovician) shows some features which remind me the structure of an ant-hill. I took a photo from the top and from the side to show the 3D of this. It could look like a burrow. Any idea? Thanks! Jean Edited April 9, 2014 by JeanB JeanB Montreal, QC, Canada Ordovician, Trenton group Link to comment Share on other sites More sharing options...
rwise Posted April 9, 2014 Share Posted April 9, 2014 Pictures look similar to the "Fiddler Crab Condominiums" along Lake Grapevine in north Texas. They are the living spaces of fiddler crabs. The grainy sand like structure are the remains of what the crab eats, and then spits out. Little balls piled up. Don't know if that is appropriate for this area, but looks identical. See "Ocean Dallas" written by the Paleo Dept at SMU in Dallas for photos. Thanks for your help in advance. Link to comment Share on other sites More sharing options...
fossilized6s Posted April 9, 2014 Share Posted April 9, 2014 Huh....it does look like an anthill! I have no clue, but im interested in what some might say on this. ~Charlie~ "There are those that look at things the way they are, and ask why.....i dream of things that never were, and ask why not?" ~RFK ->Get your Mosasaur print ->How to spot a fake Trilobite ->How to identify a CONCRETION from a DINOSAUR EGG Link to comment Share on other sites More sharing options...
Herb Posted April 10, 2014 Share Posted April 10, 2014 no fiddler crabs in the Ordovician. Can you get a close up. Not enough detail to ID. "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...
JeanB Posted April 10, 2014 Author Share Posted April 10, 2014 Thanks, indeed no fiddler crab here, and certainly no ants in ordovician... But, this piece of rock may have been imported. I doubt it (and I cannot see what would be the point), but it was part of a small landscape arrangement at a ... MacDonald's along with this interesting rock (see below and if you have an idea of what it could be, it would be a bonus for me)... Herb, I will wait for the snow to melt and have a closer picture of this... while eating a BigMac... Jean JeanB Montreal, QC, Canada Ordovician, Trenton group Link to comment Share on other sites More sharing options...
Herb Posted April 10, 2014 Share Posted April 10, 2014 the only thing I see for sure is gastropods. "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...
4circle Posted April 11, 2014 Share Posted April 11, 2014 Hello Jean, You do indeed have a fossil here, and an interesting one at that. It's an agglutinous organism, and most likely a sponge. There are some organisms which - instead of going to the trouble and biological 'expense' of building a shell, test, or skeleton - secrete a sticky goo to entrap particulate debris, and use this as the basis of 'hard parts'. The most common are a group of foraminifera (the Textulariids, late Cambrian - Recent) but these are only a few mm or a cm at most in size. This is an aggultinous sponge. Whereas most sponges build a skeleton from interlocking spicules of calcite or silica, some use the 'sticky goo' tactic. The organic parts of the sponge obviously don't fossilise, but the debris does. Obviously, small debris mounds don't fossilise on their own, unless there's an underlying framework holding them together. Here, you even have the characteristic sponge morphology (which to the uninitiated can just look like blobs), but take my word for it, this was a sponge. A rare and often-overlooked find - well done indeed, especially for spotting it as a fossil! 3 Link to comment Share on other sites More sharing options...
JeanB Posted April 11, 2014 Author Share Posted April 11, 2014 (edited) Hello Jean, You do indeed have a fossil here, and an interesting one at that. It's an agglutinous organism, and most likely a sponge. There are some organisms which - instead of going to the trouble and biological 'expense' of building a shell, test, or skeleton - secrete a sticky goo to entrap particulate debris, and use this as the basis of 'hard parts'. The most common are a group of foraminifera (the Textulariids, late Cambrian - Recent) but these are only a few mm or a cm at most in size. This is an aggultinous sponge. Whereas most sponges build a skeleton from interlocking spicules of calcite or silica, some use the 'sticky goo' tactic. The organic parts of the sponge obviously don't fossilise, but the debris does. Obviously, small debris mounds don't fossilise on their own, unless there's an underlying framework holding them together. Here, you even have the characteristic sponge morphology (which to the uninitiated can just look like blobs), but take my word for it, this was a sponge. A rare and often-overlooked find - well done indeed, especially for spotting it as a fossil! Wow!!!! That's cool. Are you referring to the second pic? And if yes, do you mean the whole rock could be a sponge or part of it? I will take the total dimensions and more pictures. So I guess two gastropods got trapped in this sticky goo? The texture of that rock was a mystery to me. Is there some documents you know I could study to learn more about this interesting organism? I think I will try to buy this rock from MacDonald's... trade it with two BigMacs... Jean Edited April 12, 2014 by JeanB JeanB Montreal, QC, Canada Ordovician, Trenton group Link to comment Share on other sites More sharing options...
Tethys Posted April 11, 2014 Share Posted April 11, 2014 The anthills are an agglutinous critter fossil? How very cool! I knew protists like Gromia do that, but I had never heard of an agglutinous sponge. Link to comment Share on other sites More sharing options...
JeanB Posted April 11, 2014 Author Share Posted April 11, 2014 (edited) ? Are we talking about the anthill or the second pic? Jean Edited April 12, 2014 by JeanB JeanB Montreal, QC, Canada Ordovician, Trenton group Link to comment Share on other sites More sharing options...
4circle Posted April 12, 2014 Share Posted April 12, 2014 Hi Jean, It's the 'anthill' structure in your second and third pics in the first post (in the same link as the photo with the two arrows). Obviously, true anthills only form on soft substrates where the ants can dig and deposit. The best reference for these is an out-of-print book - "Invertebrate Zoology" by Barnes, although they get a very brief mention in Prothero "Bringing Fossils To Life". The best reference is a book currently in press. They are pretty obscure - the kind of old-school taxonomical zoology that isn't taught any more, in favour of fancy genetics etc. Link to comment Share on other sites More sharing options...
JeanB Posted April 13, 2014 Author Share Posted April 13, 2014 (edited) Thanks 4circle!!!! An ordovician sponge! That's very exciting. I am very glad I spotted that fossil. As I wrote, I will take more pictures of that rock... since I don't think I can bring it in my garden. I am searching for scientific publications on sponges and the origin of life, a very exciting subject. It seems that that the common ancestor of Metazoa was a sponge. The most amazing side is that since my first fossil find in my garden in Montreal, I did not have to go very far to discover a piece of Ordovician history when Montreal was in the tropics... Many thanks! Boy am I glad I joined this terrific forum! Jean Edited April 13, 2014 by JeanB JeanB Montreal, QC, Canada Ordovician, Trenton group Link to comment Share on other sites More sharing options...
JeanB Posted April 16, 2014 Author Share Posted April 16, 2014 (edited) I looked for description of ordovician sponges that could match the fossils in my first post. Stromatoporoids were present in the Ordovician. Some features looks similar to the anthill: «Stromatoporoids, though once classified as ancient corals or cnidarians, are now considered to be massive, calcareous sponges (Phylum Porifera) occurring first in the Ordovician era. It is due to their calcareous nature that they are so easily preserved as fossils (Kaslev 1999). They come in many shapes, including tabular, encrusting, and arm-shaped. Common features include mamelons, or irregular lumps on the surface of the massive skeleton of the organism, presumably used for expelling water that had been filtered for food (Kentucky Geological Survey 2006).» http://facweb.furman.edu/~wworthen/bio440/evolweb/ordovician/stromato.htm and here: http://www.fallsoftheohio.org/Fossil_Sponges.html from where I took the photo below... I am still searching for agglutinous sponges somewhere in the net and in books... Jean Edited April 16, 2014 by JeanB JeanB Montreal, QC, Canada Ordovician, Trenton group Link to comment Share on other sites More sharing options...
Roz Posted April 16, 2014 Share Posted April 16, 2014 Very good followup, Jean! Welcome to the forum! Link to comment Share on other sites More sharing options...
JeanB Posted April 18, 2014 Author Share Posted April 18, 2014 (edited) Hi again! I went back to have a closer look at the sponge-like fossils. Here are some close-up pictures. The whole rock is 35 X 14 inches and many apertures (about 1/8 of an inch in diameter) are distributed irregularly on the surface. The monticules are made of a collection of grain of «sands» firmly glued together. Some monticules are isolated and other are clustered. I took the liberty of posting the pics of the whole rock here. Edited April 18, 2014 by JeanB JeanB Montreal, QC, Canada Ordovician, Trenton group Link to comment Share on other sites More sharing options...
JeanB Posted April 18, 2014 Author Share Posted April 18, 2014 (edited) Here's the rest Jean In addition I found this website with some pics of sponges, some of which have the look of what I have found. http://www.mer-littoral.org/02/galerie-poriferes.php Edited April 18, 2014 by JeanB JeanB Montreal, QC, Canada Ordovician, Trenton group Link to comment Share on other sites More sharing options...
MarqusandDad Posted April 18, 2014 Share Posted April 18, 2014 I am unsure of the biological name but sea squirts also built colonies and gave the impression of a sponge or coral as they had individual critters living in little hollows one atop another in huge masses. Link to comment Share on other sites More sharing options...
MOROPUS Posted April 18, 2014 Share Posted April 18, 2014 Seasquirts don't get fossilized, due to their soft body. Only a bunch of them are recognized as Tunicata (sea squirt) in some cretaceous Laggerstatte... As far as I can remember... Link to comment Share on other sites More sharing options...
JeanB Posted April 19, 2014 Author Share Posted April 19, 2014 Were there any seasquirts in middle odovician? Jean JeanB Montreal, QC, Canada Ordovician, Trenton group Link to comment Share on other sites More sharing options...
Auspex Posted April 19, 2014 Share Posted April 19, 2014 Were there any seasquirts in middle odovician? Jean There were, and the Cambrian, and possibly before that! Tunicates are ancient. Not that I think the mystery fossil in discussion are tunicates. "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...
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