Alex Eve Posted December 30, 2020 Share Posted December 30, 2020 I found this small theropod tooth (missing the tip) in the Horseshoe Canyon Formation of Alberta a few months ago. I’m not sure on the identity of the tooth, as it’s rather Troodontid or Dromaeosaurid. It has the crown and denticle shape of a troodontid, but the serration density of a dromaeosaurid (about 3 serrations per mm). The serrations are a bit worn down fyi. Any help would be greatly appreciated, thanks! 1 Link to comment Share on other sites More sharing options...
Top Trilo Posted December 31, 2020 Share Posted December 31, 2020 Not sure what it is it but it looks a lot like your avatar “If fossils are not "boggling" your mind then you are simply not doing it right” -Ken (digit) "No fossil is garbage, it´s just not completely preserved” -Franz (FranzBernhard) "With hammer in hand, the open horizon of time, and dear friends by my side, what can we not accomplish together?" -Kane (Kane) "We are in a way conquering time, reuniting members of a long lost family" -Quincy (Opabinia Blues) "I loved reading the trip reports, I loved the sharing, I loved the educational aspect, I loved the humor. It felt like home. It still does" -Mike (Pagurus) “The best deal I ever got was getting accepted as a member on The Fossil Forum. Not only got an invaluable pool of knowledge, but gained a loving family as well.” -Doren (caldigger) "it really is nice, to visit the oasis that is TFF" -Tim (fossildude19) "Life's Good! -Adam (Tidgy's Dad) Link to comment Share on other sites More sharing options...
Runner64 Posted December 31, 2020 Share Posted December 31, 2020 I think troodontid with worn distal serrations but I could also be convinced it’s Dromaeosauridae. Whats the size? Link to comment Share on other sites More sharing options...
Alex Eve Posted December 31, 2020 Author Share Posted December 31, 2020 47 minutes ago, Runner64 said: I think troodontid with worn distal serrations but I could also be convinced it’s Dromaeosauridae. Whats the size? About 9mm long, though it is missing the tip which prob would’ve made it 10mm Link to comment Share on other sites More sharing options...
JoeS Posted December 31, 2020 Share Posted December 31, 2020 Hey, this looks exciting! Can you count (and image) the mesial denticles and post an image of the base of the tooth and of the other side? Can you confirm that the distal denticles are hooked towards the tip of the tooth? With the 3 denticles per mm on the distal side (is this a definite number?) it falls into Dromaeosaur territory, you could potentially look at a Atrociraptor marshalli tooth?! Maybe I am jumping the gun, I am just excited for you =) 2 Link to comment Share on other sites More sharing options...
Praefectus Posted December 31, 2020 Share Posted December 31, 2020 Nice tooth! I'm looking forward to seeing what the identification is. 1 Link to comment Share on other sites More sharing options...
-Andy- Posted December 31, 2020 Share Posted December 31, 2020 The denticle shapes look just like dromaeosaurid to me. The ridges reminds me of Saurornitholestes teeth and it just so happens Atrociraptor comes from Horseshoe Canyon and is a Saurornitholestinae I'd say this is Atrociraptor. Congratulations 2 Looking forward to meeting my fellow Singaporean collectors! Do PM me if you are a Singaporean, or an overseas fossil-collector coming here for a holiday! Link to comment Share on other sites More sharing options...
Alex Eve Posted December 31, 2020 Author Share Posted December 31, 2020 2 hours ago, Top Trilo said: Not sure what it is it but it looks a lot like your avatar Yep, my pfp is confirmed Troodontid from the Dino Park Formation! Link to comment Share on other sites More sharing options...
Alex Eve Posted December 31, 2020 Author Share Posted December 31, 2020 59 minutes ago, JoeS said: Hey, this looks exciting! Can you count (and image) the mesial denticles and post an image of the base of the tooth and of the other side? Can you confirm that the distal denticles are hooked towards the tip of the tooth? With the 3 denticles per mm on the distal side (is this a definite number?) it falls into Dromaeosaur territory, you could potentially look at a Atrociraptor marshalli tooth?! Maybe I am jumping the gun, I am just excited for you =) Sure! I can’t confirm the serrations hook toward the tip because they are pretty worn, but the serration “stubs” do point slightly towards there. Here I have a pic of the base and other side of the tooth, and on the latter you can see the outline of the worn medial serrations, which are at about 4 per mm. And yes, I have confirmed the 3 per mm on the distal side. Finally, Atrcoiraptor marshalli is the only known dromaeosaur from the Horseshoe Canyon, and pretty rare at only 1 described specimen known! 1 Link to comment Share on other sites More sharing options...
-Andy- Posted December 31, 2020 Share Posted December 31, 2020 1 minute ago, Alex Eve said: Sure! I can’t confirm the serrations hook toward the tip because they are pretty worn, but the serration “stubs” do point slightly towards there. Here I have a pic of the base and other side of the tooth, and on the latter you can see the outline of the worn medial serrations, which are at about 4 per mm. And yes, I have confirmed the 3 per mm on the distal side. Finally, Atrcoiraptor marshalli is the only known dromaeosaur from the Horseshoe Canyon, and pretty rare at only 1 described specimen known! Seeing this picture has made me reconsider a little. Are there faint ridges down on the side of the tooth, or is the side completely smooth? Looking forward to meeting my fellow Singaporean collectors! Do PM me if you are a Singaporean, or an overseas fossil-collector coming here for a holiday! Link to comment Share on other sites More sharing options...
Alex Eve Posted December 31, 2020 Author Share Posted December 31, 2020 5 minutes ago, -Andy- said: Seeing this picture has made me reconsider a little. Are there faint ridges down on the side of the tooth, or is the side completely smooth? The sides are completely smooth, with the exception of this very slight depression on the distal end (can be seen in the light better, but sort of shows up in this pic) Link to comment Share on other sites More sharing options...
JoeS Posted December 31, 2020 Share Posted December 31, 2020 (edited) 3 denticles distal and 4 mesial per mm does fall into what is described for Atrociraptor. What throws me off is the cross-section... maybe because it shows a section anterior to the base, which is not really preserved on the tooth, still... I only have one reference image of a Atrociraptor base posted by a TFF member with a shape I would expect: Let's hear some more opinions @Troodon @hxmendoza Edited December 31, 2020 by JoeS 1 Link to comment Share on other sites More sharing options...
Alex Eve Posted December 31, 2020 Author Share Posted December 31, 2020 3 minutes ago, JoeS said: 3 denticles distal and 4 mesial per mm does fall into what is described for Atrociraptor. What throws me off is the cross-section... maybe because it shows a section anterior to the base, which is not really preserved on the tooth, still... I only have one reference image posted by a TFF member with a shape I would expect: Let's hear some more opinions @Troodon @hxmendoza Yea this is the exact problem I’ve ran into! Shape of a Troodontid but serration density of Dromaeosaurid Link to comment Share on other sites More sharing options...
JoeS Posted December 31, 2020 Share Posted December 31, 2020 Sorry, I am sure the pros will figure this one out, maybe @Runner64's Troodontid hunch is the proper answer looking at this base. I will watch and learn 1 Link to comment Share on other sites More sharing options...
PaleoNoel Posted December 31, 2020 Share Posted December 31, 2020 Interesting tooth, compare to these troodontid and dromaeosaur teeth I found in the Judith River fm. Slightly older but similar fauna. Personally I think yours is Dromaeosaur, but I could easily be wrong. Troodontid Dromaeosaurid (cf. Saurornitholestinae) 1 Link to comment Share on other sites More sharing options...
hxmendoza Posted January 9, 2021 Share Posted January 9, 2021 This is a Saurornitholestine tooth. Since it’s from the Horseshoe Canyon Formation it is likely Atrociraptor marshalli. 4 Link to comment Share on other sites More sharing options...
TyBoy Posted January 9, 2021 Share Posted January 9, 2021 Agree Atrociraptor Link to comment Share on other sites More sharing options...
Alex Eve Posted January 10, 2021 Author Share Posted January 10, 2021 4 hours ago, hxmendoza said: This is a Saurornitholestine tooth. Since it’s from the Horseshoe Canyon Formation it is likely Atrociraptor marshalli. What would make it Saurornitholestine? Can dromaeosaurs have the Troodont shaped cross section as well? Link to comment Share on other sites More sharing options...
JoeS Posted January 10, 2021 Share Posted January 10, 2021 16 minutes ago, Alex Eve said: Can dromaeosaurs have the Troodont shaped cross section as well? Hey, I have looked into this a little. As stated previously, I do think that the posterior end of the tooth is missing as well, that's why the cross section looks not that compressed. Here an image of a cross section from a broken Saurornitholestes tooth I found on the web. Looks similarly oval. 1 Link to comment Share on other sites More sharing options...
Alex Eve Posted January 10, 2021 Author Share Posted January 10, 2021 2 hours ago, JoeS said: Hey, I have looked into this a little. As stated previously, I do think that the posterior end of the tooth is missing as well, that's why the cross section looks not that compressed. Here an image of a cross section from a broken Saurornitholestes tooth I found on the web. Looks similarly oval. Oh alright, that answers all my questions then! I thought that cross section shape was strictly Troodontid, but I guess not. Thanks for the help! Glad I can now confirm this is an Atrociraptor marshalli tooth! Link to comment Share on other sites More sharing options...
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