Dave Bailey Posted July 1, 2015 Share Posted July 1, 2015 Well, as I said in my first post, I probably wouldn't be around too much. But this fellow really needs identifying. Don't ask me what formation it's from, because that may not be possible. It's embedded in a rock that has been used as part of the newly installed breakwater and harbour entrance to Frenchmans Bay, in Pickering, Ontario. I took a few quick pictures this evening, but I will try to get more if necessary. This is a 3-exposure tonemapped B&W with a little fiddling to bring out detail. The visible portion is almost exactly two inches wide at the widest point, and I measured it at 6 inches from one end to the other, but now that I see the detail in the picture it may be a bit longer.There is an amazing amount of detail when seen close-up, but my lousy camera doesn't focus well at short range. Link to comment Share on other sites More sharing options...
Fossildude19 Posted July 1, 2015 Share Posted July 1, 2015 (edited) Looks like a cross section of an orthocone cephalopod. Regards, Edited July 1, 2015 by Fossildude19 4 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...
Dave Bailey Posted July 1, 2015 Author Share Posted July 1, 2015 Beauty, thanks! Link to comment Share on other sites More sharing options...
FossilDAWG Posted July 1, 2015 Share Posted July 1, 2015 To be more specific, I'm pretty confident in saying this belongs to the genus Actinoceras. The diagnostic characters are the large siphuncle with an open center towards the living chamber, tapering so the far end of the siphuncle is completely filled with deposits; the shape of the siphuncular segments; the asymmetric camerae (larger on one side of the shell than the other; and the presence of deposits thickening the septa. Actinoceras is very common in certain Ontario Ordovician formations, particularly the Gull River, and these formations are extensively quarried so blocks can be found in various settings such as breakwaters. These nautiloids inhabited the sea floor; the heavy siphuncle and mineral deposits in the camerae (which were put there when the animal was alive, they are not diagenic) served to weight the shell down and stably oriented so the animal could crawl around without floating off. Don 2 Link to comment Share on other sites More sharing options...
Herb Posted July 1, 2015 Share Posted July 1, 2015 if it is small enough to polish the surface it might look really nice. "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...
Dave Bailey Posted July 4, 2015 Author Share Posted July 4, 2015 if it is small enough to polish the surface it might look really nice. The rock is about the size of a coffee table. Link to comment Share on other sites More sharing options...
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