Gramps Posted December 17, 2020 Share Posted December 17, 2020 I know very little about shark teeth. I found this one a while back in Pennsylvanian (Desmoinesian) shale in northeastern Oklahoma. I am speculating this may be deltodus only because I see a nearly identical tooth labeled as deltodus on another website. The fossil is very thin (too thin to photograph the edges). Besides confirming the taxonomy, can anyone tell me which surface of the tooth is shown in Side A? Finally, would you say Side B is mainly matrix (other than the edges)? I think matrix is showing through the cracks on Side A, and that may be the only thing holding the fossil together. My wife recently got me a camera, so I am working on a gallery album in the forum. I would like to make sure I have the IDs correct before I post photos in the album, so you may be seeing several ID requests from me over the next weeks. Best wishes 2 Link to comment Share on other sites More sharing options...
Jackson g Posted December 17, 2020 Share Posted December 17, 2020 Cross section of plate looks good for a deltodus. Not familiar with the fauna there, but the look and age both fit. Could be (not convinced) psammodus sp. I am not the best with these teethplates as I've only looked into the holocephali for a few months. I would say psammodus would be generally flatter, and lack the crescent shape your plate has. Side A would have been the crusher side. The condition is pretty good, was this eroded out of limestone and found in the scraps? 1 Link to comment Share on other sites More sharing options...
Misha Posted December 17, 2020 Share Posted December 17, 2020 I agree with your ID. but these aren't sharks, they are holocephalians That is a very nice find! 1 Link to comment Share on other sites More sharing options...
Gramps Posted December 17, 2020 Author Share Posted December 17, 2020 Wow, I learn so much every time I log in. Thanks to Jackson g and Misha for sharing your knowledge. Am I understanding correctly that this type of tooth is thin, and thus may be nearly complete? This specimen is about 4 mm thick at the bulge or ridge in the middle, thinning out considerably toward the edges. Misha, than you for correcting me on the taxonomy. Holocephalian is my new term of the day. I'll be reading up on holocephalians as soon as I post this. To answer Jackson g's question, the tooth was found pretty much as you see it here. I did use a needle to pick matrix out of the groove on Side A, as the groove was full of a sand and silt cemented together by lime. This was found at a boundary where overlying shale was in contact with limestone. I had assumed the fossil came from the shale, but you may be right about it's origins in the limestone. 3 Link to comment Share on other sites More sharing options...
connorp Posted December 17, 2020 Share Posted December 17, 2020 Very nice tooth plate! Link to comment Share on other sites More sharing options...
minnbuckeye Posted December 18, 2020 Share Posted December 18, 2020 I agree with Deltodus as the likely identification. But how does one tell Sandalodus from Deltodus??? Mike 1 Link to comment Share on other sites More sharing options...
Jackson g Posted December 18, 2020 Share Posted December 18, 2020 22 hours ago, minnbuckeye said: I agree with Deltodus as the likely identification. But how does one tell Sandalodus from Deltodus??? Mike They do look alike but I think Sandalodus have more of a mound shaping. I know, not much help! 1 Link to comment Share on other sites More sharing options...
minnbuckeye Posted December 19, 2020 Share Posted December 19, 2020 Thanks @Jackson g. Is there a size difference or is one more common in the Burlington? Sorry @Gramps for taking up space on your post!! I promise no more questions. Mike Link to comment Share on other sites More sharing options...
Gramps Posted December 19, 2020 Author Share Posted December 19, 2020 12 minutes ago, minnbuckeye said: Thanks @Jackson g. Is there a size difference or is one more common in the Burlington? Sorry @Gramps for taking up space on your post!! I promise no more questions. Mike Please don't apologize. I'm also learning from the discussion. 1 Link to comment Share on other sites More sharing options...
Jackson g Posted December 21, 2020 Share Posted December 21, 2020 On 12/18/2020 at 7:37 PM, minnbuckeye said: Thanks @Jackson g. Is there a size difference or is one more common in the Burlington? Sorry @Gramps for taking up space on your post!! I promise no more questions. Mike I would think depending on where you're hunting would determine the rarity, I'm not sure on the size part though. I've found 1 sandalodus, 8 deltodus, and two or three unknown (need to do more research) plates in the past year. Deltodus sure seems to be the most common in my Henry County area at least. Link to comment Share on other sites More sharing options...
Earendil Posted December 23, 2020 Share Posted December 23, 2020 What a cool tooth! It's specifically built for crushing, that's why this group of sharks is called 'the crusher tooth sharks'! "Its webs of living gauze no more unfurl; Wrecked is the ship of pearl! And every chambered cell, Where its dim dreaming life was wont to dwell" -From The Chambered Nautilus by Oliver Wendell Holmes Link to comment Share on other sites More sharing options...
deutscheben Posted December 24, 2020 Share Posted December 24, 2020 Identification of holocephalan crusher teeth is also made more difficult because most species actually had a battery of multiple distinctively shaped tooth plates- that means there are also other Deltodus teeth that look quite different than the one you have here. Link to comment Share on other sites More sharing options...
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