Sharks of SC Posted December 14, 2009 Share Posted December 14, 2009 Hello everyone, I found this tooth several months back and assumed it was an Alopias grandis, but now I'm not so sure. The general shape just seems...off. The tooth is 100 percent and the little protrusion off of the left lobe of the root on the display side is not a break. The root also peaks in the middle of the tooth - something Ive never seen in Alopias. Any ideas? Thanks! CBK Link to comment Share on other sites More sharing options...
Northern Sharks Posted December 14, 2009 Share Posted December 14, 2009 Where was it found, and what age if you know. I'm thinking Isurus retroflexus, but it does look similar to a Cretoxyrhina I have. Could you please post a better lit picture of the display side. I think you can safely rule out giant thresher There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Sharks of SC Posted December 15, 2009 Author Share Posted December 15, 2009 (edited) The tooth was found around on a beach fringing Charleston Harbor and the mouth of the Cooper River. Because everything I find is reworked, I am unsure of the original formation, but probably Chandler Bridge or Ashley Marl. Here is a better picture of the display side: I have examples of retroflexus in my collection - none that look quite like this, but Cretoxyrhina is something I've never heard of. Im gonna look it up now. Thanks, Cade Edited December 15, 2009 by Sharks of SC Link to comment Share on other sites More sharing options...
Sharks of SC Posted December 15, 2009 Author Share Posted December 15, 2009 From what I've seen, Cretoxyrhina was Cretaceous and probably not to be found anywhere near coastal Carolinas. The tooth did look surprisingly similar, though. My fault for not specifying location/formation collected. Link to comment Share on other sites More sharing options...
THobern Posted December 15, 2009 Share Posted December 15, 2009 Looks like a thresher to me. Link to comment Share on other sites More sharing options...
Sharks of SC Posted December 15, 2009 Author Share Posted December 15, 2009 (edited) THobern, Im tempted to just agree with you. It seems like it might be a thresher by default. It doesn't really fit anywhere as a mako or parotodus, or anything else Ive ever found around here. Its just so different from every other thresher tooth Ive ever found. I contemplated the possibility of it being a lower anterior tooth, but I have what I am fairly confident is a specimen from that position that doesnt match this tooth at all. Im going to hold off on definitively calling it a thresher to see if I can find a picture of an odd position retroflexus or something that might fit the bill or someone poses another possibility. Edited December 15, 2009 by Sharks of SC Link to comment Share on other sites More sharing options...
Northern Sharks Posted December 15, 2009 Share Posted December 15, 2009 Something about the root shape has me leaning away from A.grandis, plus the minimal curve to the blade. It could be that I'm wrong, and it's just the tooth position. Your shot of the back side does look like my grandis teeth, except for the odd shape. The root looks very much like Parotodus from the front/back, but from the end view, it seems too thin. There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
THobern Posted December 15, 2009 Share Posted December 15, 2009 (edited) I've seen thresher teeth with roots like that, but what makes me fairly certain that it's A. grandis is that thinner enamel on the back of the tooth. Edited December 15, 2009 by THobern Link to comment Share on other sites More sharing options...
Sharks of SC Posted December 15, 2009 Author Share Posted December 15, 2009 (edited) I really wish you could see this tooth in person. It looks like the root and the enamel were "pinched" into a little dome right in the middle of the root where it meets the crown - its something I cant capture in the pics. Im also thrown off by the bourlette-like band of enamel between root and crown. Here are a few more angles: CBK Edited December 15, 2009 by Sharks of SC Link to comment Share on other sites More sharing options...
siteseer Posted December 16, 2009 Share Posted December 16, 2009 I really wish you could see this tooth in person. It looks like the root and the enamel were "pinched" into a little dome right in the middle of the root where it meets the crown - its something I cant capture in the pics. Im also thrown off by the bourlette-like band of enamel between root and crown. Here are a few more angles: CBK CBK, Yeah, I was looking at your tooth for some time last night. I noticed what appeared to be an embossed area of the root where it meets the crown - a classic indicator of retroflexus. In river teeth, this character can be irregularly eroded or completely eroded. However, I'm prevented from providing a confident ID by the fact that the crown appears not as flat as it should be for retroflexus. I'm leaning away from grandis. If pressed for an opinion, I would say it's an odd retroflexus lower lateral. One of the Dutch or Belgian collectors would have more experience with retroflexus (Lee Creek collectors too - I've seen a few from Virginia sites too) and be able to give you a more definite opinion. Link to comment Share on other sites More sharing options...
Sharks of SC Posted December 16, 2009 Author Share Posted December 16, 2009 On the elasmo site I found a picture of the dentition of the modern I. paucus that has a similar-looking upper lateral tooth, but still not too conclusive. Im going to take the tooth, along with some other curiousities to the Cypress Garden Fossil Show in Feb. and Ill see if I can learn anything else. I know a few guys who I would consider "experts" will be attending, so I think Ill clear it up there if not sooner. thanks for your responses, CBK Link to comment Share on other sites More sharing options...
siteseer Posted December 16, 2009 Share Posted December 16, 2009 On the elasmo site I found a picture of the dentition of the modern I. paucus that has a similar-looking upper lateral tooth, but still not too conclusive. Im going to take the tooth, along with some other curiousities to the Cypress Garden Fossil Show in Feb. and Ill see if I can learn anything else. I know a few guys who I would consider "experts" will be attending, so I think Ill clear it up there if not sooner. thanks for your responses, CBK CBK, Upper mako teeth don't have U-shaped basal root margins. Let us know what you hear at the show. Link to comment Share on other sites More sharing options...
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