Harry Pristis Posted November 8, 2012 Share Posted November 8, 2012 (edited) Here's another interesting fossil that turned up in my storage . . . a Tilly bone that has been sawed in half. I took some close-ups with my camera (unhappily, my microscope camera software is not compatible with my new Intel Core i5 processor). But, I think you can see the gross structure and identify the bone, a pterygiophora ("ter-RIJ-ee-AH-for-ah", I think). Tilly bones are bone overgrowths of unknown etiology. This one is from a fish axial skeleton with bilateral symmetry. A pterygiophora is the basal spine (within the fish body) which supports and articulates with the dorsal fin spine on the body exterior. Show us some more Tilly bones. Edited November 9, 2012 by Harry Pristis 2 http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
Harry Pristis Posted November 8, 2012 Author Share Posted November 8, 2012 I cranked up my older computer to make this microscope image: The white dots within the trefoil section represent voids in the original bone -- cancellate bone. The overgrowth seems to be without those voids. http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
Bullsnake Posted November 8, 2012 Share Posted November 8, 2012 Interesting, Harry! I've learned something new from this. Thank you! Steve Link to comment Share on other sites More sharing options...
Starling Posted November 14, 2012 Share Posted November 14, 2012 Tilly bones are nornal growths in bony fish, they act like ballast Link to comment Share on other sites More sharing options...
Al Dente Posted November 14, 2012 Share Posted November 14, 2012 Tilly bones are nornal growths in bony fish, they act like ballast That they act as ballast is a common misconception. Hyperostic bones (Tilly bones) frequently occurs in the head and dorsal region. These are not regions you would want ballast. In modern fish the density of hyperostotic bones is about the same as muscle tissue.* Smith-Vaniz, Kaufman and Glowacki discuss this in "Species-specific patterns of hyperostosis in marine teleost fishes" Marine Biology 1995 vol 121. Link to comment Share on other sites More sharing options...
darrow Posted November 15, 2012 Share Posted November 15, 2012 tilly bones... Link to comment Share on other sites More sharing options...
DeloiVarden Posted June 19, 2015 Share Posted June 19, 2015 Here are some of the fossil tilly bones I have found so far. Link to comment Share on other sites More sharing options...
DeloiVarden Posted June 19, 2015 Share Posted June 19, 2015 Here is the pic Link to comment Share on other sites More sharing options...
Harry Pristis Posted June 20, 2015 Author Share Posted June 20, 2015 Here is the pic That specimen on the bottom-right of your image is strange. Can you provide a couple of different views? http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
DeloiVarden Posted June 20, 2015 Share Posted June 20, 2015 That specimen on the bottom-right of your image is strange. Can you provide a couple of different views? Here you go Harry. The piece does seem different in that it looks to be composed of sandy material (maybe cast). Link to comment Share on other sites More sharing options...
Plantguy Posted June 20, 2015 Share Posted June 20, 2015 Sorry Harry I missed this original post of yours...hmm, I never thought about cutting one in half-----interesting to see one in section. That last example is rather odd isnt it...not only in composition but also in the unique shape--not sure I have any like that...I'll have to go look in the pile...thanks for the photos. Regards, Chris Link to comment Share on other sites More sharing options...
Harry Pristis Posted June 20, 2015 Author Share Posted June 20, 2015 (edited) Here you go Harry. The piece does seem different in that it looks to be composed of sandy material (maybe cast). Wow! That is different. I don't think it's a Tilly bone, though. At least, it's not like any Tilly bone I've ever seen. I think your "cast" suggestion is a likely identification. A cast of a burrow by some invert, I'd say. Not all Tilly bones are bilaterally symmetrical. But, we can say that a very sizeable proportion of those that come to our attention (a collecting bias?) are from the axial skeleton and thus tend toward bilateral symmetry. Witness the assortment of finds you've presented, DeV. What did you find, Chris? Does anyone here have fossil Tilly bones that don't tend toward bilateral symmetry? Please show us. Edited June 20, 2015 by Harry Pristis http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
Harry Pristis Posted June 20, 2015 Author Share Posted June 20, 2015 Earlier today, I stumbled (literally) across a flat containing some phosphate mine miscellany. Among the odds and ends were these Tilly bones. Most, perhaps all, of these are vertebrae. I don't know if any of them are associated with the others. None is anything close to perfectly symmetrical, but you may be able to see the tendency toward bilateral symmetry. 1 http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
Plantguy Posted June 21, 2015 Share Posted June 21, 2015 Well, this is going to be more difficult than I thought...I've got a bunch of things that are possible tillys that I'll have to photograph later but as I was looking at a number of specimens I was certain of I'm now intrigued by the different textures and wondering if I've got something else So here's one I found at the Bowling Green Mosaic mine, Hardee County, FL which has some good symmetry but not perfect. 1 Link to comment Share on other sites More sharing options...
Plantguy Posted June 21, 2015 Share Posted June 21, 2015 Here's a couple with some very interesting textures from Sarasota County, FL. 1 Link to comment Share on other sites More sharing options...
Plantguy Posted June 21, 2015 Share Posted June 21, 2015 Here's one of the brain like shapes. 1 Link to comment Share on other sites More sharing options...
Plantguy Posted June 21, 2015 Share Posted June 21, 2015 Lastly here are two additional ones with more interesting textures. The one on the right has some really intriuging raised bumps/areas along its base. More as I get to them. Regards, Chris Link to comment Share on other sites More sharing options...
Harry Pristis Posted June 21, 2015 Author Share Posted June 21, 2015 Those are cool, Chris! I have never before seen those textures; but, I don't doubt that they are Tilly bones. http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
RichW9090 Posted June 21, 2015 Share Posted June 21, 2015 Harry, can you show the other side of the bone in the lower right of your flat of phosphate mine material? The plural of "anecdote" is not "evidence". Link to comment Share on other sites More sharing options...
Mike Price Posted March 21, 2017 Share Posted March 21, 2017 Very informative thread. I found a big and small tilly bones and fin spines on the Brazos River, Texas. I will try to post several pics as this format allows. 1 Link to comment Share on other sites More sharing options...
Mike Price Posted March 22, 2017 Share Posted March 22, 2017 Link to comment Share on other sites More sharing options...
Mike Price Posted March 22, 2017 Share Posted March 22, 2017 Link to comment Share on other sites More sharing options...
Mike Price Posted March 22, 2017 Share Posted March 22, 2017 Link to comment Share on other sites More sharing options...
Mike Price Posted March 22, 2017 Share Posted March 22, 2017 Link to comment Share on other sites More sharing options...
Shellseeker Posted March 22, 2017 Share Posted March 22, 2017 Mike, Great Pictures!! I am intensely interested in identifying specific tilly bones to specific fish: Do you have such knowledge? A couple of mine, The last one I JUST found and my hunting friend said he thought it was shark. The White Queen ".... in her youth she could believe "six impossible things before breakfast" Link to comment Share on other sites More sharing options...
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