Baryonyx Posted March 12, 2018 Share Posted March 12, 2018 Is the white part down there peeled of enamel or the root. It also looks like a port of the tooth was cut or worn down. Link to comment Share on other sites More sharing options...
Baryonyx Posted March 12, 2018 Author Share Posted March 12, 2018 Link to comment Share on other sites More sharing options...
Baryonyx Posted March 12, 2018 Author Share Posted March 12, 2018 Unfortunately I can't upload more pictures. Link to comment Share on other sites More sharing options...
jpc Posted March 12, 2018 Share Posted March 12, 2018 the white stripe looks like a wear facet. The white at the base is the top of the root. 1 Link to comment Share on other sites More sharing options...
Baryonyx Posted March 12, 2018 Author Share Posted March 12, 2018 10 minutes ago, jpc said: the white stripe looks like a wear facet. The white at the base is the top of the root. Where exactly does the root begin? Link to comment Share on other sites More sharing options...
Troodon Posted March 12, 2018 Share Posted March 12, 2018 I'm with jpc looks like a wear facet but that is very uncommon with Spinosaurid teeth. The root should begin around where the enamel ends. Reminder we don't know what Spinosaurid species this tooth belongs to. We don't even know if Spinosaurus aegyptiacus is valid in Morocco 1 Link to comment Share on other sites More sharing options...
Baryonyx Posted March 12, 2018 Author Share Posted March 12, 2018 But isn't most of spino material that is found Moroccan? I mean didn't Niza Ibrahim find the spino bones for his reconstruction in Morocco? Link to comment Share on other sites More sharing options...
Baryonyx Posted March 12, 2018 Author Share Posted March 12, 2018 And what exactly do you mean with feeding facet? Isn't it too smooth to be worn of by feeding. Link to comment Share on other sites More sharing options...
jerdin007 Posted March 12, 2018 Share Posted March 12, 2018 Hello all, This is my opinion on the white parts in the spinosaur tooth. The first picture shows the enamel above and the white part below is the root. The boundary between enamel and root is not a straight line in spinosaur teeth. The best way to show that the white part is the root and not peeled off enamel is by looking at the tooth under a binocular. You will notice that the enamel is thick at the tip and gets very thin gradually at the root-enamel boundary. If it would be peeled-off enamel, then the enamel will still be thick but I guess that's not the case here. On the second picture you can again recognize the root by the dull coarse white surface. The shiny smooth white surface is not a wear facet (as in created by feeding) in my opinion. A first argument is the triangular portion of enamel that is sticking out. In a wear facet, I think this should also have worn off. So what do we have if this is not a wear facet? I think that the enamel broke off, together with a thin portion of dentine. Dentine is built up in layers. These layers are separated from each other by thin lines called the von Ebner lines. I think the dentine broke just along such a surface which creates the smoothness. You can see a spinosaur teeth as cones of dentine on top of each other as in the picture of Goedert et al (2016) and I think it is along such a cone that the tooth broke. As argument, you can see that the white smooth surface extends in the root (made up of dentine) and it creates a small rim. I hope what I wrote here is clear enough to express my thoughts. Kind greetings Jeroen from Belgium 1 Link to comment Share on other sites More sharing options...
Baryonyx Posted March 12, 2018 Author Share Posted March 12, 2018 7 minutes ago, jerdin007 said: Hello all, This is my opinion on the white parts in the spinosaur tooth. The first picture shows the enamel above and the white part below is the root. The boundary between enamel and root is not a straight line in spinosaur teeth. The best way to show that the white part is the root and not peeled off enamel is by looking at the tooth under a binocular. You will notice that the enamel is thick at the tip and gets very thin gradually at the root-enamel boundary. If it would be peeled-off enamel, then the enamel will still be thick but I guess that's not the case here. On the second picture you can again recognize the root by the dull coarse white surface. The shiny smooth white surface is not a wear facet (as in created by feeding) in my opinion. A first argument is the triangular portion of enamel that is sticking out. In a wear facet, I think this should also have worn off. So what do we have if this is not a wear facet? I think that the enamel broke off, together with a thin portion of dentine. Dentine is built up in layers. These layers are separated from each other by thin lines called the von Ebner lines. I think the dentine broke just along such a surface which creates the smoothness. You can see a spinosaur teeth as cones of dentine on top of each other as in the picture of Goedert et al (2016) and I think it is along such a cone that the tooth broke. As argument, you can see that the white smooth surface extends in the root (made up of dentine) and it creates a small rim. I hope what I wrote here is clear enough to express my thoughts. Kind greetings Jeroen from Belgium Thanks do you have more information about spinosaurus teeth and how they are build. Link to comment Share on other sites More sharing options...
Troodon Posted March 12, 2018 Share Posted March 12, 2018 46 minutes ago, Baryonyx said: But isn't most of spino material that is found Moroccan? I mean didn't Niza Ibrahim find the spino bones for his reconstruction in Morocco? No Spinosaurids are found all over the world including Niger, Algeria and Egypt. We have multiple Spinosaurid in the Kem Kem Sigilmassasaurus and Spinosaurus and we know so little there may be others. Ibrahim finding are not accepted by many paleontologists that are familiar with the region. More is unknown than known. 1 Link to comment Share on other sites More sharing options...
Troodon Posted March 12, 2018 Share Posted March 12, 2018 53 minutes ago, Baryonyx said: And what exactly do you mean with feeding facet? Isn't it too smooth to be worn of by feeding. Wear facets are normally smooth and are caused by the opposing tooth rubbing on it mostly during feeding A paper on Tyrannosaurids https://www.app.pan.pl/article/item/app50-093.html 1 Link to comment Share on other sites More sharing options...
jerdin007 Posted March 12, 2018 Share Posted March 12, 2018 Hi Baryonyx, First of all, thanks for finding my post informative. It's not that there is a paper out there on how spinosaur teeth are build. I based myself mostly on what I could see on the pictures and on what I saw on my own spinosaur teeth that I studied for my thesis. The picture comes from a study on isotopes: https://www.researchgate.net/publication/291955600_Preliminary_investigation_of_seasonal_patterns_recorded_in_the_oxygen_isotope_compositions_of_theropod_dinosaur_tooth_enamel This picture was made based on histology studies but they study only thin sections, not entire teeth so I guess that's not so interesting for you. I hope this helps. Jeroen 1 Link to comment Share on other sites More sharing options...
Baryonyx Posted March 13, 2018 Author Share Posted March 13, 2018 8 hours ago, Troodon said: Wear facets are normally smooth and are caused by the opposing tooth rubbing on it mostly during feeding A paper on Tyrannosaurids https://www.app.pan.pl/article/item/app50-093.html But the paper says that it mostly appears on the lingual side of the tooth. That's not the case with mine. Link to comment Share on other sites More sharing options...
Troodon Posted March 13, 2018 Share Posted March 13, 2018 5 hours ago, Baryonyx said: But the paper says that it mostly appears on the lingual side of the tooth. That's not the case with mine. Paper was just provided address your question on what feeding facets are and that they are smooth. Spinosaurid's have a very different jaw structure than Tyrannosaurids so it's a different dynamic but don't know if its been studied. We are just guessing on what happened to your tooth since like I said it's not a common feature you see on Spinosaurids. 1 Link to comment Share on other sites More sharing options...
Baryonyx Posted March 13, 2018 Author Share Posted March 13, 2018 3 hours ago, Troodon said: Paper was just provided address your question on what feeding facets are and that they are smooth. Spinosaurid's have a very different jaw structure than Tyrannosaurids so it's a different dynamic but don't know if its been studied. We are just guessing on what happened to your tooth since like I said it's not a common feature you see on Spinosaurids. You think someone cut it or polished it off? It goes to the root not only the enamel. And how big do spinosaur teeth get? Link to comment Share on other sites More sharing options...
Troodon Posted March 13, 2018 Share Posted March 13, 2018 Unless you were there when it happened everything is speculation. No idea how big Spino crowns get I've seen crowns over 5 inches. 1 Link to comment Share on other sites More sharing options...
Haravex Posted March 13, 2018 Share Posted March 13, 2018 can't believe there is a spinosauridae post I have missed anyway its my understanding that they do get facet wear, here is one from my own inventory. 3 Link to comment Share on other sites More sharing options...
Troodon Posted March 13, 2018 Share Posted March 13, 2018 4 minutes ago, Haravex said: can't believe there is a spinosauridae post I have missed anyway its my understanding that they do get facet wear, here is one from my own inventory. Nice to see one, not common 1 Link to comment Share on other sites More sharing options...
Baryonyx Posted March 13, 2018 Author Share Posted March 13, 2018 2 hours ago, Haravex said: can't believe there is a spinosauridae post I have missed anyway its my understanding that they do get facet wear, here is one from my own inventory. The wear off looks exactly like on mine! Thank you for your picture it helps a lot! Do you have more Spinosaurus material that I can compare to my tooth? Link to comment Share on other sites More sharing options...
Haravex Posted March 14, 2018 Share Posted March 14, 2018 I have many many spinosauridae teeth it depends what you mean to compare with troodon, made a fantastic post highlighting the differences in kem kem theropod teeth maybe have a look at that thread. 1 Link to comment Share on other sites More sharing options...
zekky Posted March 14, 2018 Share Posted March 14, 2018 Could have just had a tooth come in a bit off and grow up into the other tooth. 1 Link to comment Share on other sites More sharing options...
Baryonyx Posted March 14, 2018 Author Share Posted March 14, 2018 5 hours ago, Haravex said: I have many many spinosauridae teeth it depends what you mean to compare with troodon, made a fantastic post highlighting the differences in kem kem theropod teeth maybe have a look at that thread. Already know that post thanks. Link to comment Share on other sites More sharing options...
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