sjbaird Posted December 17, 2016 Share Posted December 17, 2016 Hi. I'm new to the Forum, but would like some opinions about this object I found here in Alaska. It was found in a tidal creek in an estuary in southcentral Alaska. The estuary surface is a mix of gravel, mud, and glacial silt. I've shown this to various local experts, and most think it is some kind of broken fossil, but a few think it isn't a fossil at all. Any thoughts would be appreciated. Link to comment Share on other sites More sharing options...
sjbaird Posted December 17, 2016 Author Share Posted December 17, 2016 A few more photos. Link to comment Share on other sites More sharing options...
LordTrilobite Posted December 17, 2016 Share Posted December 17, 2016 Sure looks like a type of bone. Olof Moleman AKA Lord Trilobite Link to comment Share on other sites More sharing options...
ynot Posted December 17, 2016 Share Posted December 17, 2016 Welcome to ! It does look like a bone, but I think it is a concretion. There is no evidence of bone structure in the areas that should show the coarse marrow structures. These areas look more like a sandstone. (Could be a cast of a bone or something else(?)) Tony Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
sjbaird Posted December 17, 2016 Author Share Posted December 17, 2016 To me it has always looked like a broken part of a zygomatic arch from a mammal skull. The color is very similar to some mammal fossils I've seen also. It looks too organic to be a concretion to me. However, that interior structure that should look like bone is what has led some to conclude that it is not a fossil. Others, however, are just as sure that it is fossil. Anyone else want to weigh in? Link to comment Share on other sites More sharing options...
JohnJ Posted December 18, 2016 Share Posted December 18, 2016 Sharper images of the broken surfaces will go a long way in assisting an ID. The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
fifbrindacier Posted December 18, 2016 Share Posted December 18, 2016 Less blurry ones of each end of it also. "On ne voit bien que par le coeur, l'essentiel est invisible pour les yeux." (Antoine de Saint-Exupéry) "We only well see with the heart, the essential is invisible for the eyes." In memory of Doren Link to comment Share on other sites More sharing options...
sjbaird Posted December 18, 2016 Author Share Posted December 18, 2016 Here are some attempts at sharper photos of the broken edges. I'm having trouble getting decent depth of field. Link to comment Share on other sites More sharing options...
westcoast Posted December 18, 2016 Share Posted December 18, 2016 Initially i thought ironstone but looks like bone, particularly the second image in the latest close up images. Not a clue what kind however Link to comment Share on other sites More sharing options...
ynot Posted December 18, 2016 Share Posted December 18, 2016 I still see a concretion. The internal structure is made of spherical objects of varying size and desperation, A bone would have a consistent pattern of irregular shapes. Also the "wall" is way to thin for a bone structure. Tony Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
sjbaird Posted December 18, 2016 Author Share Posted December 18, 2016 To me it has always looked like a broken part of a zygomatic arch from a mammal skull. The color is very similar to some mammal fossils I've seen also. It looks too organic to be a concretion to me. However, that interior structure that should look like bone is what has led some to conclude that it is not a fossil. Others, however, are just as sure that it is fossil. Anyone else want to weigh in? Is there anyone I could send this to for some definitive ID? Are there paleontologists who are willing to do such things? We are slowly accumulating evidence that there were Pleistocene mammals on the Kenai Peninsula, mostly from scattered mammoth teeth and some steppe bison remains. It would be interesting to see if this could add to that understanding. Link to comment Share on other sites More sharing options...
Fossildude19 Posted December 18, 2016 Share Posted December 18, 2016 I took the liberty of brightening/contrasting your pictures. It looks like an oolitic ironstone concretion, to me. Regards, Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
Darktooth Posted December 18, 2016 Share Posted December 18, 2016 I have found many of these in the streambed of Big Brook New Jersey. When I was much less knowledgeable in fossils I fell for the suggestive shape and appearance of these concretions. But like Tony has already pointed out, the internal structure is made up of coarse grains. It is not a bone. The proof is in the structure. I like Trilo-butts and I cannot lie. Link to comment Share on other sites More sharing options...
Darktooth Posted December 18, 2016 Share Posted December 18, 2016 By the way, I still fall for faux-fossils now and then. I like Trilo-butts and I cannot lie. Link to comment Share on other sites More sharing options...
westcoast Posted December 19, 2016 Share Posted December 19, 2016 Yeah. Those latest pictures cleared things up. I'm back in the 'mineral that looks like bone' camp. I've had a few. Particularly with ironstone. Link to comment Share on other sites More sharing options...
sjbaird Posted December 19, 2016 Author Share Posted December 19, 2016 Thanks, all. Glad to have this cleared up. Link to comment Share on other sites More sharing options...
snail Posted December 19, 2016 Share Posted December 19, 2016 Hello everyone; I am enjoying reading this forum and seeing what people find. Thank you all. Here is an interesting link obliquely related to this thread, some have probably already seen it: http://www.thecanadianencyclopedia.ca/en/article/quaternary-vertebrate-fossils/ Link to comment Share on other sites More sharing options...
sjbaird Posted December 19, 2016 Author Share Posted December 19, 2016 One last question for those of you who have a good understanding of geology: how does the thin rich brown layer on the outer surface form, what is it composed of, and why does the object have such a deceptively organic shape? I guess that was actually three last questions. Link to comment Share on other sites More sharing options...
ynot Posted December 19, 2016 Share Posted December 19, 2016 It forms from iron in the surrounding rock/soil oxidizing around a nucleus, often of some biologic material. Iron oxides. Concreations like to take a variety of shapes some that resemble things that We recognize, and Our brains try to fit a shape to an unknown object. (Ever see shapes in the clouds). Tony Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
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