BobC Posted June 15, 2009 Share Posted June 15, 2009 Can you guys help me ID this guy? He came from a quarry that is loaded with ammonites and at first, because of the ridges, I thought it was part of an ammonite. Below are pics of the front, side, top and bottom. He is about five inches long Link to comment Share on other sites More sharing options...
BobC Posted June 15, 2009 Author Share Posted June 15, 2009 Front view Link to comment Share on other sites More sharing options...
BobC Posted June 15, 2009 Author Share Posted June 15, 2009 Side view Link to comment Share on other sites More sharing options...
BobC Posted June 15, 2009 Author Share Posted June 15, 2009 top Link to comment Share on other sites More sharing options...
Auspex Posted June 15, 2009 Share Posted June 15, 2009 The septa are not ornate; that should narrow it down. "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...
LanceH Posted June 15, 2009 Share Posted June 15, 2009 I think one chamber of a nautilus, internal mold of course. You can see the impression of the siphuncle on the smooth concave side. The opposite side is convex where it fit into another concave section. There's very strong external ribbing which I've never seen on nautilus (Cymatoceras from late Albian-early Cenomanian age) fossils I've found in North Texas. What formation or age is yours from? Link to comment Share on other sites More sharing options...
BobC Posted June 15, 2009 Author Share Posted June 15, 2009 Not sure what a septa is Link to comment Share on other sites More sharing options...
ashcraft Posted June 15, 2009 Share Posted June 15, 2009 My thought would have been oyster- exogyra or similar. Brent Ashcraft ashcraft, brent allen Link to comment Share on other sites More sharing options...
barefootgirl Posted June 15, 2009 Share Posted June 15, 2009 That first pict looks just like some of the nautiloids I find. I think you have a piece of a nautiloid. I could be wrong though. In formal logic, a contradiction is the signal of defeat: but in the evolution of real knowledge, it marks the first step in progress toward victory. Alfred North Whithead 'Don't worry about the world coming to an end today. It's already tomorrow in Australia!' Link to comment Share on other sites More sharing options...
BobC Posted June 15, 2009 Author Share Posted June 15, 2009 Definitely not an oyster. Lance you are probably right. I have found several ammonites with extremely visible ridges like this, but not many. Like this one Link to comment Share on other sites More sharing options...
LanceH Posted June 15, 2009 Share Posted June 15, 2009 Given that the siphuncle is near the center of the chamber that makes it a nautilus and not an ammonite which has it's siphuncle near the edge. Also the basic outline of the chamber and simplicity is a giveaway. Link to comment Share on other sites More sharing options...
jpbowden Posted June 15, 2009 Share Posted June 15, 2009 Lance is quite right, it's not an oyster, it's missing a much needed scar. Link to comment Share on other sites More sharing options...
BobC Posted June 15, 2009 Author Share Posted June 15, 2009 You guys are talking way over my head. I thought an ammonite was the shell of a nautilus? Link to comment Share on other sites More sharing options...
Traviscounty Posted June 16, 2009 Share Posted June 16, 2009 You guys are talking way over my head. I thought an ammonite was the shell of a nautilus? I had to look up siphuncle (I thought it was an uncle that sucks). Link to comment Share on other sites More sharing options...
tracer Posted June 16, 2009 Share Posted June 16, 2009 You guys are talking way over my head. I thought an ammonite was the shell of a nautilus? no, an ammonite and a nautilus would both be cephalopods, but they are not part of each other. ammonites are pretty much not amongst the living any more (may their siphuncles rest in peace), whereas nautiluses(?)(actually probably nautiloidisms or nautilischians), still live and are kinda like the only semi-cousinesque relatives from whom the ammonites could try to borrow money if they were still alive to try. Link to comment Share on other sites More sharing options...
Auspex Posted June 16, 2009 Share Posted June 16, 2009 You guys are talking way over my head. I thought an ammonite was the shell of a nautilus? Try Googling "ammonite and nautilus anatomy" three times fast... "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...
Ammonoid Posted June 16, 2009 Share Posted June 16, 2009 Or Cephalopod Shell Morphology (a shameless plug) Kevin Link to comment Share on other sites More sharing options...
BobC Posted June 16, 2009 Author Share Posted June 16, 2009 Uhhh gotcha. So it's officially a ridgeback whackaddoodle. Link to comment Share on other sites More sharing options...
BobC Posted June 16, 2009 Author Share Posted June 16, 2009 My Canadian friends who went fossil hunting with me this weekend just bought me a book on ammonites--and the book has a diagram of the various interior features of ammonites. It's very interesting. I am conquering my idiocy one book at a time! Link to comment Share on other sites More sharing options...
Guest Inyo Posted June 16, 2009 Share Posted June 16, 2009 My thought would have been oyster- exogyra or similar.Brent Ashcraft I agree. It's a poorly preserved oyster of some kind. Photos #1 and #4 confirm the identification. Photo #1 shows one of the two distinctive oyster shells that comprise the invertebrate critter; #4 reveals the "plications", or folds of an oyster. Fossils From Pleistocene Lake Manix, California http://inyo2.110mb.com/manix/manixlakebeds.html Link to comment Share on other sites More sharing options...
LanceH Posted June 16, 2009 Share Posted June 16, 2009 Here's a link to a PDF of "Lower Cretaceous Nautiloids of Texas". There are two picture plates at the end of the PDF. http://www.scribd.com/doc/13839175/lower-c...oids-from-texas Link to comment Share on other sites More sharing options...
BobC Posted June 16, 2009 Author Share Posted June 16, 2009 Thanks! Link to comment Share on other sites More sharing options...
jpbowden Posted June 17, 2009 Share Posted June 17, 2009 I agree. It's a poorly preserved oyster of some kind. Photos #1 and #4 confirm the identification. Photo #1 shows one of the two distinctive oyster shells that comprise the invertebrate critter; #4 reveals the "plications", or folds of an oyster.Fossils From Pleistocene Lake Manix, California http://inyo2.110mb.com/manix/manixlakebeds.html No it is not and oyster, it is not from the Pleistocene, though it is of the mollusk family it chose to swim about and not just lay there. Link to comment Share on other sites More sharing options...
BobC Posted June 17, 2009 Author Share Posted June 17, 2009 Pat is the Oyster King of Central Texas--and although I agree certain views of this guy suggest an oyster or a clam, I can say that if there is any central Texas fossil type I can ID, it's oysters, clams, snails and (mostly) echinoids. After researching the inner workings of ammonites and such, I agree that this guy is part of one. I showed this fossil to my two Canadian ammonite-lover-friends, and they didn't know what it was, so I thought I'd ask the experts here on the FF. No offense intended--but central Texas is over-run with fossil oysters and this ain't one of them/ Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted June 17, 2009 Share Posted June 17, 2009 Your ammonite is Oxytropidoceras and your nautiloid is Paracymatoceras. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
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