New Members rayb2229 Posted June 30, 2022 New Members Share Posted June 30, 2022 Found this tooth in Jacksonville Florida, wondering if it's a Dino tooth. Any help would be appreciated. The tooth is about one inch long and 3/4 wide. Thank you Link to comment Share on other sites More sharing options...
Troodon Posted June 30, 2022 Share Posted June 30, 2022 Its a mosasaur tooth looks like its from Morocco 4 Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted June 30, 2022 Share Posted June 30, 2022 +1 for Moroccan mosasaur - how on earth did it get there!? The tooth seems to be Mosasaurus beaugei, from the Late Cretaceous (~70mya) of the Oulad Abdoun Basin phosphate deposits in Morocco. ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
Praefectus Posted June 30, 2022 Share Posted June 30, 2022 It is a Moroccan mosasaurid tooth. Robust base and thick enamel near the tip identifies it as Prognathodon. 6 minutes ago, IsaacTheFossilMan said: The tooth seems to be Mosasaurus beaugei, from the Late Cretaceous (~70mya) of the Oulad Abdoun Basin phosphate deposits in Morocco. The Cretaceous component of the Moroccan Phosphates is 67-66 Ma. 1 Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted June 30, 2022 Share Posted June 30, 2022 5 hours ago, Praefectus said: The Cretaceous component of the Moroccan Phosphates is 67-66 Ma. Sounds about right, I couldn't recall the exact year, and felt a bit lazy! 5 hours ago, Praefectus said: Robust base and thick enamel near the tip identifies it as Prognathodon. There appears to be longitudinal faceting on the crown, leading to my suspicion as M. beaugei - which can have a robust base, too. From Identifying North African (Moroccan) mosasaur teeth – Deposits Mag @rayb2229's tooth also appears to be very triangular in cross-sectional nature, which is a tell-tale for M. b., as well. Ray, would you be able to send a photo of the root of the tooth? Prognathodon has sub-circular lateral shape. Prognathodon giganteus also bears no visible faceting. The only other Prognathodon described from the Ouled Abdoun Basin is P. currii, which is most definitely not this tooth! 1 ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted June 30, 2022 Share Posted June 30, 2022 I'm trying to learn the palaeontologist's compass, so, let me have a crack at asking for the bottom of the tooth... Please bear with me, and definitely give me feedback on how well I did! I believe this is the posterior view? Let's have a go... @rayb2229, can you attach a photo of the tooth posteriorly shown? @Troodon Help! ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
Troodon Posted June 30, 2022 Share Posted June 30, 2022 13 hours ago, IsaacTheFossilMan said: I'm trying to learn the palaeontologist's compass, so, let me have a crack at asking for the bottom of the tooth... Please bear with me, and definitely give me feedback on how well I did! I believe this is the posterior view? Let's have a go... @rayb2229, can you attach a photo of the tooth posteriorly shown? @Troodon Help! Although the photos are dino they are similar with all species L Applicable everywhere 1 1 Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted June 30, 2022 Share Posted June 30, 2022 28 minutes ago, IsaacTheFossilMan said: There appears to be longitudinal faceting on the crown, leading to my suspicion as M. beaugei - which can have a robust base, too. From Identifying North African (Moroccan) mosasaur teeth – Deposits Mag Having handled mosasaur teeth from Morocco, Jordan, the US (multiple locations), France and the Low Countries, as well as having seen examples from the UK, Germany, Sweden and a bunch of other places across the world myself, and meaning no disrespect to George, I'd really recommend you read Serge's excellent thread on Moroccan mosasaurs. Working from Morocco, he's probably one of the most knowledgable people on mosasaurs from the region, and that thread has become the de-facto guide to identification of Moroccan mosasaur teeth. I've used it myself when I started out collecting Moroccan teeth and have made various contributions to that thread, which you may find useful as well. 5 hours ago, IsaacTheFossilMan said: The tooth seems to be Mosasaurus beaugei With that information source in hand, your identification of the tooth as Mosasaurus beaugei is problematic as teeth in the genus Mosasaurus have a couple of features in common, namely their U-/D-shaped cross-section and their mediodistal curvature. That is to say, when compared to other mosasaur teeth, those of the genus Mosasaurus have a rather flat labial surface and convex lingual one, with the tooth curving backwards and inwards towards the tongue. And while the surface texture of these teeth may have a lightly roughened texture, the enamel overall is smooth. Teeth are slightly (M. hoffmannii) to notably (M. beaugei) prismatic, with M. beaugei having flat-bottomed to concave facets lingually, them being much fewer in number and much less notable in M. hoffmannii. Here's an example of a nice and crisp Mosasaurus beaugei: Ray's tooth has (sub)equal buccal and lingual sides, with the darkened tip being an indication of the presence of thickened enamel and thus durophageous adaptations - something shared by prognathodontids. This identification is confirmed by the mesiodistal curve of the tooth (i.e., running in the line of the jaw). In other words, it's the shape of the tooth and the characteristics of the enamel that give it away (other genera have other morphological features to look out for, such as enamel folds or striae along the base or crown, compression, or restricted curvature towards the tooth apex). Now the problem with Moroccan prognathodontids is that a lot of confusion exists around their exact identification, as Trevor has beautifully summarised here. As such, some authors do observe the mild faceting seen on Ray's tooth in Prognathodon anceps. However, there are indications that P. anceps and P. giganteus may be conspecific - typically having unfaceted teeth - while also eliciting presence of another, as yet unrecognized prognathontid, namely P. solvayi. This species has faceted teeth, however is problematic as it's currently only known from what appears to be a juvenile individual from Belgium. The Moroccan teeth are significantly bigger and mosasaur researchers also traditionally consider Morocco and Belgium to consist of two distinct palaeogeographic regions, each with their own palaeobiota. However, this is likely a paucity in study of material from the northern regions as compared to Morocco, which has presented us with an incomparable wealth of information. In Europe, however, mosasaur teeth are rare finds, and thus less well studied, with plenty of space for new discoveries breaking down this established view. Trevor and I recently did this for Mosasaurus hoffmannii, previously only known from the boreal regions of the Low Countries. But conversely, Carinodens belgicus, formerly only known from the north, has since also been recognized in Morocco, which equally goes for prognathodontid species and even the tylosaurine Hainosaurus. All in all, these regions were not as distinct as once believed, and there's no reason to reject the hypothesis that P. solvayi may have been present in Morocco. Whether Ray's tooth can be attributed to P. solvayi, however, is a different matter, as this depends on resolution of the question of whether regular Moroccan prognathodontid species could bear facets as well. For there are certainly teeth out there, in Morocco, that are prognathodontid but have much clearer faceting. I hope this helps explains things a bit. 4 'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted July 1, 2022 Share Posted July 1, 2022 (edited) 12 hours ago, pachy-pleuro-whatnot-odon said: Having handled mosasaur teeth from Morocco, Jordan, the US (multiple locations), France and the Low Countries, as well as having seen examples from the UK, Germany, Sweden and a bunch of other places across the world myself, and meaning no disrespect to George, I'd really recommend you read Serge's excellent thread on Moroccan mosasaurs. Working from Morocco, he's probably one of the most knowledgable people on mosasaurs from the region, and that thread has become the de-facto guide to identification of Moroccan mosasaur teeth. I've used it myself when I started out collecting Moroccan teeth and have made various contributions to that thread, which you may find useful as well. With that information source in hand, your identification of the tooth as Mosasaurus beaugei is problematic as teeth in the genus Mosasaurus have a couple of features in common, namely their U-/D-shaped cross-section and their mediodistal curvature. That is to say, when compared to other mosasaur teeth, those of the genus Mosasaurus have a rather flat labial surface and convex lingual one, with the tooth curving backwards and inwards towards the tongue. And while the surface texture of these teeth may have a lightly roughened texture, the enamel overall is smooth. Teeth are slightly (M. hoffmannii) to notably (M. beaugei) prismatic, with M. beaugei having flat-bottomed to concave facets lingually, them being much fewer in number and much less notable in M. hoffmannii. Here's an example of a nice and crisp Mosasaurus beaugei: Ray's tooth has (sub)equal buccal and lingual sides, with the darkened tip being an indication of the presence of thickened enamel and thus durophageous adaptations - something shared by prognathodontids. This identification is confirmed by the mesiodistal curve of the tooth (i.e., running in the line of the jaw). In other words, it's the shape of the tooth and the characteristics of the enamel that give it away (other genera have other morphological features to look out for, such as enamel folds or striae along the base or crown, compression, or restricted curvature towards the tooth apex). Now the problem with Moroccan prognathodontids is that a lot of confusion exists around their exact identification, as Trevor has beautifully summarised here. As such, some authors do observe the mild faceting seen on Ray's tooth in Prognathodon anceps. However, there are indications that P. anceps and P. giganteus may be conspecific - typically having unfaceted teeth - while also eliciting presence of another, as yet unrecognized prognathontid, namely P. solvayi. This species has faceted teeth, however is problematic as it's currently only known from what appears to be a juvenile individual from Belgium. The Moroccan teeth are significantly bigger and mosasaur researchers also traditionally consider Morocco and Belgium to consist of two distinct palaeogeographic regions, each with their own palaeobiota. However, this is likely a paucity in study of material from the northern regions as compared to Morocco, which has presented us with an incomparable wealth of information. In Europe, however, mosasaur teeth are rare finds, and thus less well studied, with plenty of space for new discoveries breaking down this established view. Trevor and I recently did this for Mosasaurus hoffmannii, previously only known from the boreal regions of the Low Countries. But conversely, Carinodens belgicus, formerly only known from the north, has since also been recognized in Morocco, which equally goes for prognathodontid species and even the tylosaurine Hainosaurus. All in all, these regions were not as distinct as once believed, and there's no reason to reject the hypothesis that P. solvayi may have been present in Morocco. Whether Ray's tooth can be attributed to P. solvayi, however, is a different matter, as this depends on resolution of the question of whether regular Moroccan prognathodontid species could bear facets as well. For there are certainly teeth out there, in Morocco, that are prognathodontid but have much clearer faceting. I hope this helps explains things a bit. Thank you for your reply, it was very interesting! However, I'm still not fully sold. M. beaugei is known to have pretty thick enamel on the tip, and also to have a robust base. I have several M. b. in my collection, and, while there is diversity within the species, they do have thicker enamel and robust bases. I wasn't aware of Moroccan prognathodontid having faceting, do you have a link to a study on this? Edited July 1, 2022 by IsaacTheFossilMan ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted July 1, 2022 Share Posted July 1, 2022 17 minutes ago, IsaacTheFossilMan said: Thank you for your reply, it was very interesting! However, I'm still not fully sold. M. beaugei is known to have pretty thick enamel on the tip, and also to have a robust base. Do you have a source for this, as this information is incorrect. Even George's article - while incorrectly illustrating a faceted prognathodontid as M. beaugei - states that (emphasis mine): Quote In Mosasaurus beaugei (Arambourg 1952), the tooth crowns are described as robust with both carinae (cutting edges) having fine visible serrations, the most noticeable feature is the very distinctive and pronounced longitudinal prism-shaped facets on the tooth crown. The teeth are almost triangular in cross section and the facets can also be even more pronounced. Why I'm pointing this out is because most Moroccan teeth that are described as "robust" actually have round/subcircular cross-sections at the base. Again, M. beaugi belongs to the genus Mosasaurus and therefore, while certain teeth may be more heavy-set than others and certain ones may also exhibit more anastomosing ridges than others, their teeth generally have 1) a triangular-like cross-section in the horizontal plane, with a notable twist and backwards curvature of the tooth leading up to the apex and 2) relatively smooth enamel. Compare with the specimen from the below overview, for example (Bardet, Houssaye, Vincent, Suberbiola, Amaghzaz, Jourani, & Meslouh, 2014): Have a look at the below threads for further examples of M. beaugei teeth: 17 minutes ago, IsaacTheFossilMan said: I have several M. b. in my collection, and, while there is diversity within the species, they do have thicker enamel and robust bases. I'd be very interested in seeing some of your specimens, if only because I wonder whether these are indeed M. beaugei. When I first started collecting Moroccan mosasaur teeth, I got a lot of my pieces from a Dutch student who identified various teeth as M. beaugei, whereas they were actually P. giganteus, for example. Now I doubt this particular confusion will occur too much these days, but M. beaugei is one of those species that often gets confused and, at the same time, ends up being a waste-bucket taxon for a lot of other species, including M. hoffmannii and tylosaurine teeth. For, the difference in robustness between Moroccan prognathodontids and M. beaugei is quite notable, with the thickened enamel being an obvious feature of prognathodontids but being almost always absent in Mosasaurus. Complicating this distinction, however, is Eremiasaurus heterodontus, which teeth generally look like recurved conical prognathodontid teeth, including the thickened enamel and darker colouring towards the tip of the tooth, though their anterior teeth have only an anterior carina. These teeth, too, can sometimes be faceted or prismatic. So I'm thinking that if you describe robust M. beaugei teeth with vastly different morphologies, you might actually be talking about prismatic prognathodontid teeth on the one hand and E. heterodontus ones on the other... 17 minutes ago, IsaacTheFossilMan said: I wasn't aware of Moroccan prognathodontid having faceting, do you have a link to a study on this? Unfortunately not, as this is based on the personal observations of people who have handled a lot of specimens of Moroccan mosasaur teeth. The thing is that the prognathodontids of Morocco, right now, are a bit of a taxonomic mess, with mosasaur researchers not able to decide whether Prognathodon anceps is the same species as Prognathodon giganteus, nor whether P. solvayi occurs in Morocco. At the same time, only very few academics are looking into the issue, leaving collectors like us to draw our own conclusions. However, looking beyond just the confines of Morocco, you might find Machalski et al. (2003) and Lingham-Soliar and Nolf (1989, esp. pp. 158-160) of interest. 2 'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett Link to comment Share on other sites More sharing options...
Praefectus Posted July 1, 2022 Share Posted July 1, 2022 15 hours ago, IsaacTheFossilMan said: There appears to be longitudinal faceting on the crown, leading to my suspicion as M. beaugei - which can have a robust base, too. From Identifying North African (Moroccan) mosasaur teeth – Deposits Mag Hi @IsaacTheFossilMan. This tooth is from George Corneille's old article on Moroccan mosasaur teeth. I have spoken with him a bit since then and we have come to the conclusion that it was misidentified and is actually Prognathodon. Which species it belongs to is an issue that is still being determined (either P. solvayi or P. "anceps" based on the surface fluting) and hopefully new discoveries will help provide more insight into its identification. For a more recent review of Moroccan mosasaurs, I recommend giving Bardet 2015 a read. There have been a few more species discovered in the phosphate since, but this paper does a good basic overview of the most common tooth shapes. Below are a few pictures of actual Mosasaurus beaugei teeth for comparison. Note the generally taller crown, sharper apex, prominent cutting edges, and increased degree of recurvature. Unfortunately, there are not many good pictures of Mosasaurus beaugei fossil material in the academic literature. Hopefully, this will be corrected soon. 1 2 Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted July 1, 2022 Share Posted July 1, 2022 3 hours ago, pachy-pleuro-whatnot-odon said: I'd be very interested in seeing some of your specimens, if only because I wonder whether these are indeed M. beaugei. Our very own @Praefectus ID'd this one, and the others all look the same! www.thefossilforum.com/uploads/monthly_2021_11/IMG_20211127_213725353.jpg.6daa6fc3d495d3ccd57211072551a682.jpg Well, thank you both for the papers to read, this is very interesting! 1 hour ago, Praefectus said: Some of these do appear to have rather thick enamel, and the base of @rayb2229's tooth does appear to be consistent with this tooth in particular: I believe I see prominent cutting edges on Ray's tooth, too. I guess we will have to wait for pictures from all around! Ray, can you attach photos of the tooth attached to some card or paper (perhaps with temporary sticky-tack), so we can see both sides of the tooth, and the edges, too? And perhaps even a nice picture of the bottom of the tooth would be useful, too. Thanks! Isaac ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted July 1, 2022 Share Posted July 1, 2022 Reading Bardet (2015), in fig. 4, item C appears to be like Ray's tooth, and is IDd as M. b. ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted July 1, 2022 Share Posted July 1, 2022 2 hours ago, Praefectus said: Hi @IsaacTheFossilMan. This tooth is from George Corneille's old article on Moroccan mosasaur teeth. I have spoken with him a bit since then and we have come to the conclusion that it was misidentified and is actually Prognathodon. Which species it belongs to is an issue that is still being determined (either P. solvayi or P. "anceps" based on the surface fluting) and hopefully new discoveries will help provide more insight into its identification. That does make sense, it does look pretty dang prognathodontid - maybe it would make sense to update the website, though? Cheers for the insight, will definitely use the resources you sent me instead! Man, learning is fun! Thank you so so much for your patience and wisdom, @Praefectus and @pachy-pleuro-whatnot-odon, you guys have been ever so helpful! Now, all we have to do is wait for some more photos 2 ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted July 1, 2022 Share Posted July 1, 2022 17 hours ago, Troodon said: Although the photos are dino they are similar with all species L Applicable everywhere Ah, also, thanks! Really appreciate it ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
Praefectus Posted July 1, 2022 Share Posted July 1, 2022 1 hour ago, IsaacTheFossilMan said: Our very own @Praefectus ID'd this one, and the others all look the same! www.thefossilforum.com/uploads/monthly_2021_11/IMG_20211127_213725353.jpg.6daa6fc3d495d3ccd57211072551a682.jpg eeeeeeeee! I get nervous when people quote my own identifications back to me. I have made a lot of misidentifications in the past. (I think I got that one right, though). 1 hour ago, IsaacTheFossilMan said: Reading Bardet (2015), in fig. 4, item C appears to be like Ray's tooth, and is IDd as M. b. This one is M. beaugei. It is a terrible example because it doesn't show the facets on the lingual surface and has a worn apex that makes it look less sharp. Note that it is still taller than Ray's tooth. It is really unfortunate that the tooth is only shown in labial view. Differentiating Prognathodon and Mosasaurus teeth is a lot easier when you have labial, lingual, anterior, posterior, and basal views. You will notice that Prognathodon is a lot stouter and mostly circular around the base while Mosasaurus is more hook-like and D-shaped at the base. I wish I could send you some side-by-side photos of the different views, but I'm away from my collection right now. I have this picture on my phone showing two particularly large examples of Prognathodon and Mosasaurus beaugei teeth where the differences are exaggerated. 1 hour ago, IsaacTheFossilMan said: Some of these do appear to have rather thick enamel, and the base of @rayb2229's tooth does appear to be consistent with this tooth in particular: Do you see how the color of Ray's tooth gets darker near the tip? This is caused by the enamel thickening near the apex of Prognathodon teeth so that they can be used for biting/crushing. Mosasaurus teeth are generally uniform in enamel thickness, though do exhibit a little bit of thickening near the apex in some teeth. It is always to a lesser degree in Mosasaurus, though. 1 Link to comment Share on other sites More sharing options...
New Members rayb2229 Posted July 1, 2022 Author New Members Share Posted July 1, 2022 I just want to thank everyone that took the time to help me ID this tooth. I appreciate the links as well, good reads and lots of information! 2 Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted July 1, 2022 Share Posted July 1, 2022 1 hour ago, Praefectus said: Differentiating Prognathodon and Mosasaurus teeth is a lot easier when you have labial, lingual, anterior, posterior, and basal views. Don't forget apical, which can be very informative as to curvature 1 hour ago, Praefectus said: I wish I could send you some side-by-side photos of the different views, but I'm away from my collection right now. Same here... Though I do have nice faceted prognathodontid and clear M. beaugei teeth in my collection that would make for a good side-by-side comparison, I'm really pressed on time due to my move right now (a condition that'll last for weeks!), so can unfortunately not take any photographs. But then I'll be away from that part of my collection as of tomorrow, so that also precludes me taking them until much later... 1 hour ago, Praefectus said: Do you see how the color of Ray's tooth gets darker near the tip? This is caused by the enamel thickening near the apex of Prognathodon teeth so that they can be used for biting/crushing. Mosasaurus teeth are generally uniform in enamel thickness, though do exhibit a little bit of thickening near the apex in some teeth. It is always to a lesser degree in Mosasaurus, though. Yup, I think that's one of the things I keep forgetting to mention: the thickening of the enamel in prognathodontids and their overall different shape in general is indicative of different feeding habits. As such, it makes sense to see certain adaptations in prognathodontids and not in Mosasaurus and the other way around. That is, prognathodontids likely ate much harder prey items, a condition taken to the extreme by P. currii and the globidensini, whereas Mosasaurus used its teeth much more for cutting. See the below image, figure 7 from the same Bardet et al. (2014) referenced above. Observe the globidensini and P. currii towards the left along the bottom axis, the halisaurini and plioplatecarpines along the right diagonal, Mosasaurus at the bottom right, and prognathodontids immediately left of that on the bottom axis. 1 'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted July 1, 2022 Share Posted July 1, 2022 4 hours ago, Praefectus said: Mosasaurus teeth are generally uniform in enamel thickness, though do exhibit a little bit of thickening near the apex in some teeth. It is always to a lesser degree in Mosasaurus, though. I have seen M. b. teeth with considerable thickening towards the apex, as you say, it is possible, but atypical. 4 hours ago, Praefectus said: eeeeeeeee! I get nervous when people quote my own identifications back to me. I have made a lot of misidentifications in the past. (I think I got that one right, though). I feel you... 4 hours ago, Praefectus said: It is really unfortunate that the tooth is only shown in labial view. Differentiating Prognathodon and Mosasaurus teeth is a lot easier when you have labial, lingual, anterior, posterior, and basal views. Yeah, 100%, as with lots of other fossils. I'm really waiting for Ray to send a basal shot of the tooth, then I'll count myself a believer! @rayb2229 4 hours ago, Praefectus said: You will notice that Prognathodon is a lot stouter and mostly circular around the base while Mosasaurus is more hook-like and D-shaped at the base. Exactly what I'm looking for, yeah. As Mosasaurus occupied differing ecological niches to Prognathodon, the latter occupying more crushing for shelled creatures such as ammonites, and the former occupying serration for slicing and cutting through softer bodied prey, you expect to note pronounced edges on M., similar to that of a kitchen knife, whereas P. expects a rounded, blunt tip, such as a pestle (pestle and mortar). Right now I'm really playing picture analysis games with the shadows from Ray's pictures: Note that the apex is almost touching the paper, which wouldn't be expected for a circular conical tooth, whereas both sides of it appear to taper off to a complete curve, looking like that D shape: @rayb2229, please throw us a bone, here! ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted July 1, 2022 Share Posted July 1, 2022 6 minutes ago, IsaacTheFossilMan said: Note that the apex is almost touching the paper, which wouldn't be expected for a circular conical tooth, whereas both sides of it appear to taper off to a complete curve, looking like that D shape: Actually, you would. As with any cone put down onto a flat surface the tip won't just keep floating into the air, but will also lie down on the surface, thereby increasing the incline that runs from tip to base. Give it a try and you'll see for yourself 'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted July 1, 2022 Share Posted July 1, 2022 1 minute ago, pachy-pleuro-whatnot-odon said: Actually, you would. As with any cone put down onto a flat surface the tip won't just keep floating into the air, but will also lie down on the surface, thereby increasing the incline that runs from tip to base. Give it a try and you'll see for yourself Hence my third clause, that each side seem to taper off to a semicircle - the base is also touching the ground, but has a slice! ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted July 1, 2022 Share Posted July 1, 2022 @pachy-pleuro-whatnot-odon Both lines are of similar height, indicating an flat(ter) side. ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
IsaacTheFossilMan Posted July 1, 2022 Share Posted July 1, 2022 @rayb2229, from our wonderful @Fossildude19 Tim: ~ Isaac; www.isaactfm.com "Don't move! He can't see us if we don't move!" - Alan Grant Come to the spring that is The Fossil Forum, where the stream of warmth and knowledge never runs dry. Link to comment Share on other sites More sharing options...
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