joeride95 Posted December 22, 2021 Share Posted December 22, 2021 This Mosasaurus tooth measures 8.3 inches from Morocco. Can you tell me what species it is? 1 Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted December 29, 2021 Share Posted December 29, 2021 Oh, that's a nice sizeable specimen! Mosasaur teeth generally curve either along the mesiodistal plane or the labiolingual one, with the latter being an indication of the tooth belonging to a species from the genus Mosasaurus. This condition seems to be the case here. With prism faces on the labial side of the tooth and facets on the lingual, this tooth can further be narrowed down to M. beaugei. 1 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...
R0b Posted December 29, 2021 Share Posted December 29, 2021 (edited) Doesn’t look like 8.3 inches though I guess cm Edited December 29, 2021 by R0b 1 Link to comment Share on other sites More sharing options...
Paleorunner Posted December 29, 2021 Share Posted December 29, 2021 30 minutes ago, R0b said: Doesn’t look like 8.3 inches though I guess cm They are centimeters, otherwise, the tooth and the hand would be of a huge size. By the way, good piece. Link to comment Share on other sites More sharing options...
joeride95 Posted January 2, 2022 Author Share Posted January 2, 2022 Yes, it's centimeters, I was wrong . Thank you all Link to comment Share on other sites More sharing options...
abyssunder Posted January 2, 2022 Share Posted January 2, 2022 Nice tooth! 1 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Praefectus Posted January 3, 2022 Share Posted January 3, 2022 Nice tooth. It is a real whopper! The identification is Prognathodon sp. aff. Prognathodon solvayi. Mosasaurus beaugei and Mosasaurus hoffmannii both have a U-shaped cross-section formed from the labial surface being flattened and the lingual surface being rounded. The fluted Moroccan Prognathodon has a more rounded labial surface and concave flutes on both surfaces. I'm not 100% certain the Moroccan fluted Prognathodon is Prognathodon solvayi. OP's tooth has a posterior carinae that swings laterally while the holotype of Prognathodon solvayi has carinae that are all antero-posteriorly oriented. Here is a picture of the tooth next to gigantic examples of Mosasaurus beaugei (middle) and Mosasaurus hoffmannii (right). 1 1 Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted January 4, 2022 Share Posted January 4, 2022 3 hours ago, Praefectus said: OP's tooth has a posterior carinae that swings laterally while the holotype of Prognathodon solvayi has carinae that are all antero-posteriorly oriented. Hence my position that the sub-equal cross-section this creates is actually more in line with Mosasaurus (thus, M. beaugei for it's ornamentation), rather than Prognathodon. In my opinion, there's too much labiolingual curvature (in Prognathodon spp. curvature is really more mesiodistally, much like the positioning of the carinae). But I guess that from the photographs it really depends on what features you emphasise, since I do agree that it's not entirely clear what exact shape the cross-section has. May be some proper apical (seen from the top) and basal (seen from the bottom) photographs could help clarify this. And there does seem to be some durophagous adaptation, which would also point more towards P. sp. aff. P. solvayi, rather than M. beaugei. However, from specimens ascribed to M. hoffmannii that I've seen in the Low Countries, it appears to me that teeth of Mosasaurus can also have a more convex labial surface, thus giving them a more rounded appearance in cross-section (e.g. the below specimen or the M. hoffmannii referred specimen from the Museum voor Natuurwetenschappen in Brussels below it). If this, however, were to be P. sp. aff. solvayi, then the curvature in the tooth would need to be explained as something positional, indicative of a position towards the front of the jaw, such as the area around the premaxilla. However, the P. solvayi holotype (photograph below again from the Museum voor Natuurwetenschappen in Brussels) has conical teeth in this area, which have been recovered from Moroccan phosphate deposits as well. As such, I'm currently undecided about whether to classify the tooth as M. beaugei or P. sp. aff. solvayi. 3 hours ago, Praefectus said: Here is a picture of the tooth next to gigantic examples of Mosasaurus beaugei (middle) and Mosasaurus hoffmannii (right). Nice teeth! 1 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...
Praefectus Posted January 4, 2022 Share Posted January 4, 2022 I wonder what role gigantism plays in tooth shape. @joeride95's tooth is over triple the size of the holotype material of Prognathodon solvayi. Perhaps ontogenetic changes could explain the differences???An alternative explanation is that there may be another new species of unnamed Prognathodon in the Moroccan Phosphates. I don't see the big tooth fitting into the Mosasaurus beaugei dentition. 14 hours ago, pachy-pleuro-whatnot-odon said: Nice teeth! I know. If only I could afford them... Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted January 4, 2022 Share Posted January 4, 2022 3 hours ago, Praefectus said: I wonder what role gigantism plays in tooth shape. @joeride95's tooth is over triple the size of the holotype material of Prognathodon solvayi. Perhaps ontogenetic changes could explain the differences??? Well, ontogenesis does seem to account for differences in the ornamentation of some reptile teeth, including those of mosasaurs, and it is known from various animal species that young have different feeding patterns from adults. It also seems likely to me, considering the degree of bone separation observed in the P. solvayi holotype skull, that the holotype specimen represents a juvenile, thus allowing for Moroccan teeth of the same species to potentially be larger. However, I don't think reorientation of the dental curvature has been reported or observed for any mosasaur species yet. I'd also be very much surprised if this were at any point established, as all currently recognized prognathodontids have mesiodistal curvature of the teeth (i.e., including adults and potential juveniles)... Then again, there are very few ontogenetic growth series to base such conclusions on, most of which - much like the hypothesis of Mosasaurus lemonieri being the juvenile variant of M. hoffmannii or the American Tylosaurus growth series proposed by Zietlow (2020) - remain contested. So it is certainly a possibility, although I'm not quite convinced... 3 hours ago, Praefectus said: An alternative explanation is that there may be another new species of unnamed Prognathodon in the Moroccan Phosphates. I don't see the big tooth fitting into the Mosasaurus beaugei dentition. Always possible something new will still be found, since, in fact, P. sp. aff. solvayi has also not officially been described from Morocco yet. However, then there's this (taken from Instagram): Although OP's tooth doesn't quite look the same as this, I'd say there's less ambiguity of this being a M. beaugei. This tooth is reported as being 8.2cm tall, so about the size of OP's, showing, at least in my mind, that teeth from M. beaugei could attain such size. The only thing that throws me off somewhat is the fact that there seem to be some anastomosing enamel ridglets on OP's specimen not typically seen on teeth assigned to the genus Mosasaurus. However, this doesn't mean they aren't there, as the morphological definition of M. hoffmannii does include anastomosing ridglets, just not this prominent... 3 hours ago, Praefectus said: I know. If only I could afford them... I was so sure these were part of your collection already! But I guess there's always room for more! '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 January 4, 2022 Share Posted January 4, 2022 53 minutes ago, pachy-pleuro-whatnot-odon said: However, I don't think reorientation of the dental curvature has been reported or observed for any mosasaur species yet. I was afraid you would say that. It makes the identification of these teeth much more uncertain. 54 minutes ago, pachy-pleuro-whatnot-odon said: the American Tylosaurus growth series proposed by Zietlow (2020) The potential synonymy and growth series made by combining Tylosaurus kansasensis and Tylosaurus nepaeolicus has been disproven. Stewart and Mallon 2018 responded to Jimenez-Huidobro et al., 2016's initial hypothesis. I personally asked Zeitlow about about T. kansasensis and she admitted that increasing her sample size pointed towards the two species being separate. 1 hour ago, pachy-pleuro-whatnot-odon said: Although OP's tooth doesn't quite look the same as this, I'd say there's less ambiguity of this being a M. beaugei. This tooth is reported as being 8.2cm tall, so about the size of OP's, showing, at least in my mind, that teeth from M. beaugei could attain such size. The only thing that throws me off somewhat is the fact that there seem to be some anastomosing enamel ridglets on OP's specimen not typically seen on teeth assigned to the genus Mosasaurus. However, this doesn't mean they aren't there, as the morphological definition of M. hoffmannii does include anastomosing ridglets, just not this prominent... Yeah, M. beaugei gets big. Here is my whopper. Crown height is just under 7.5 cm. I think the anastomosing enamel is evidence pointing towards OP's tooth being prognathodontid, but I guess future discoveries will tell. 1 hour ago, pachy-pleuro-whatnot-odon said: I was so sure these were part of your collection already! But I guess there's always room for more! I wish! haha. I am sure there will be more big teeth found in the future. Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted January 4, 2022 Share Posted January 4, 2022 15 minutes ago, Praefectus said: I was afraid you would say that. It makes the identification of these teeth much more uncertain. Long live mosasaur heterodonty! 15 minutes ago, Praefectus said: The potential synonymy and growth series made by combining Tylosaurus kansasensis and Tylosaurus nepaeolicus has been disproven. Stewart and Mallon 2018 responded to Jimenez-Huidobro et al., 2016's initial hypothesis. I personally asked Zeitlow about about T. kansasensis and she admitted that increasing her sample size pointed towards the two species being separate. Good to know, as I hadn't heard about that before! At the time I originally read the article the argument sounded convincing and I didn't have the tools to critically evaluate its finding, so it's good to have that pointed out 15 minutes ago, Praefectus said: Yeah, M. beaugei gets big. Here is my whopper. Crown height is just under 7.5 cm. I think the anastomosing enamel is evidence pointing towards OP's tooth being prognathodontid, but I guess future discoveries will tell. That's a really nice specimen! And while I agree that the anastomosing enamel is unexpected for M. beaugei, one of the main reasons I'm still clinging to that identification is that I've got a tooth here that measures just under 7.5cm like yours, has labiolingual curvature with clearly sub-equal labial and lingual sides for an U-shaped cross-section, but has coarse enamel texture all over the tooth, but especially nearer the apex: But as you said, who knows what's still out there and what future discoveries will teach us 15 minutes ago, Praefectus said: I wish! haha. I am sure there will be more big teeth found in the future. Yeah, they seem to be popping up quite a bit right now. Would love to add a tooth above the 8cm mark to my collection if I could afford it - but unfortunately that's not now '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 January 5, 2022 Share Posted January 5, 2022 6 minutes ago, pachy-pleuro-whatnot-odon said: And while I agree that the anastomosing enamel is unexpected for M. beaugei, one of the main reasons I'm still clinging to that identification is that I've got a tooth here that measures just under 7.5cm like yours, has labiolingual curvature with clearly sub-equal labial and lingual sides for an U-shaped cross-section, but has coarse enamel texture all over the tooth, but especially nearer the apex: Oh wow! The enamel does get thicker towards the apex of that tooth. Nice one... Well, this complicates things. I think the high degree of labiolingual curvature can be explained by it being one of the anteriormost tooth positions. Unfortunately, jaw position hand-wavery doesn't explain the thicker enamel towards the apex. I am not sure how I feel about using the word anastomosing to describe the enamel on your big tooth. Usually, that is reserved for Prognathodon and other durophages where the enamel is even thicker and the surface pattern is more pronounced. 16 minutes ago, pachy-pleuro-whatnot-odon said: Yeah, they seem to be popping up quite a bit right now. Would love to add a tooth above the 8cm mark to my collection if I could afford it - but unfortunately that's not now Is it too much to ask for 8 cm teeth still attached to a piece of jawbone? Perhaps I am being too greedy. 1 1 Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted January 5, 2022 Share Posted January 5, 2022 9 hours ago, Praefectus said: I am not sure how I feel about using the word anastomosing to describe the enamel on your big tooth. Usually, that is reserved for Prognathodon and other durophages where the enamel is even thicker and the surface pattern is more pronounced. You are, of course, right in that the term anastomosing in marine reptile dentition is typically (and therefore conceptually) associated with durophagous adaptations, such as those seen in the globidensini, P. currii or machimosauridae. Similar structures have, however, been observed in species and clades considered non-durophagous, such as British (Cretaceous) brachauchenine pliosaurs. Madzia (2016), however, refers to this kind of enamel ornamentation as "vermicular striae", although, as can be seen from below photograph (figure 7, ibid.), the ridglets are structurally very similar to the anastomosing ridglets seen in durophagous marine reptiles. I've just taken another close look at the roughening enamel of my tooth, and these are indeed caused by intertwining ridglets similar to those observed on the pliosaur tooth above, as well as on durophagous mosasaurs like P. currii (although these striae are somewhat more pronounced on those teeth). You'll also observe them on certain M. hoffmannii teeth, although again in their weaker form. While an argument could be made to call these weaker striations vermiculations, the term anastomosis, strictly speaking, still applies to them, as the term simply refers to intertwining biological structures (including blood and plant veins) - even if I agree that it feels a bit odd to apply the term to my tooth. In any case, as these structures can be observed in globidensini, prognathodontidae and mosasaurini - albeit their prominence of expression differs - I speculate that this morphological feature is ancestral to all of these clades and therefore probably a synapomorphy of mosasaurinae that in many of its genera, as in Mosasaurus, has become vestigial, yet sometimes still gets expressed. 10 hours ago, Praefectus said: Is it too much to ask for 8 cm teeth still attached to a piece of jawbone? Perhaps I am being too greedy. Well, there's still plenty of material coming out of Morocco and they say it's good to aim high, right? So, who knows! 2 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...
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