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Vaches Noires: plesiosaur tooth or fish tooth after all?


pachy-pleuro-whatnot-odon

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Hi all,

 

Last summer, while out hunting at the Vaches Noires on the Normandy coast of France, we found the below tooth in the Marnes de Dives (upper Callovian)

.1918080266_FieldphotoplesiosaurtoothVachesNoires.thumb.jpg.8b230f3bc8221435d2732cca42d66763.jpg

 

I extracted it from its matrix in order to be able to tell with confidence whether carinae are present or not and thus whether the tooth could be metriorhynchid - which I thought, at the time, to be the only other major contender. Carinae are not present. As such, I then arrived at the conclusion that the tooth is plesiosaurian, and in absence of striations - anastomosing or other - that it probably belonged to Cryptoclidus sp.. This is the state in which it has remained since then.

 

546521402_VachesNoirestoothscale.thumb.jpg.f599a8c3bb7d4e692e96424b73bc04fb.jpg1311559809_VachesNoirestoothlateral.jpg.b3bf92eeca9c0ff6e16d04243576ef21.jpg

 

1807248337_VachesNoirestoothlabial.jpg.1c4250da6bcaebdd0a6ddfbd3e885044.jpg303665721_VachesNoirestoothlingual.jpg.ebddf97a4fe8c53197d0cf0c8faaf131.jpg

 

1778605395_VachesNoirestoothbasal.thumb.jpg.6f707bb3dff28a10f2f13fadaf0c2acc.jpg1868496691_VachesNoirestoothapical.jpg.830278a259d042df04fec945ca7b6e82.jpg

 

601de60e87bca_oxfordclayplesiosaurteeth.jpg.f8aa95899493a585be843e6c31ce2ff9.jpg

From left to right: Muraenosaurus leedsi, Cryptoclidus oxoniensis and Tricleidus seeleyi (Noè, Taylor and Gómez-Pérez, 2017)

 

 

However, I keep occasionally bumping into Hypsocormus sp., a pachycormiform fish with a temporal range from the Callovian stage of the Middle Jurassic all the way through the Late Jurassic up to the Cretaceous - most recently today with the jaw below. And I must certainly say that I see some semblances...

 

1390851125_Hypsocormussp.fishjaw.jpg.15bfda0baaaa92a3a8dc374556976eaf.jpg

Specimen from the Oxford Clay at Peterborough

 

1073754422_Pachycormiformfishtooth.jpg.c7932d24ddfd695d66a08de4e4dd6351.jpg

An unidentified pachycormiform fish tooth from the Oxfordian levels of Vaches Noires (source) that I, here, suggest may, in fact, represent Hypsocormus sp..

 

990674877_HypsocormusfishtoothfromtheBolounnaisjden182.jpg.d087f5184d79c95317f7dd883a42b8ef.jpg1030042813_HypsocormusfishtoothfromtheBolounnaisjden186.jpg.1380c9bfabe1d3903f754524de300f42.jpg

 

Two specimens of Hypsocormus sp. from further up north on the French coast, in the Boulonnais, dating to the Kimmeridgian/Tithonian (source). Given sizes are 6.45mm and 13.1mm respectively.

 

302226060_HypsocormusteethfromtheLowerOxfordClay.thumb.jpg.4eefa146fab815c2dd0898fdd310c0e9.jpg

Two Hypsocormus sp. specimens from the Lower Oxford Clay, UK (specific locality unknown; source).

 

193596592_HypsocormusfishtoothfromtheTournusregionofSaneetLoire01.jpg.92d682de61ed3c750b84f787658e1d4d.jpg454869448_HypsocormusfishtoothfromtheTournusregionofSaneetLoire02.jpg.264d5b2faff03fd2443b8204637d8d79.jpg605771053_HypsocormusfishtoothfromtheTournusregionofSaneetLoire03.jpg.e30f94a616e9507224a304d7682247c2.jpg

 

Hypsocormus sp. from the Callovian of the Tournus-region of Saône et Loire in France (source).

 

One thing that stands out from all the specimens that I've been able to identify online is that most have an notable acrodin cap, which clearly marks them as fish teeth. It's based on this that I've identified the below tooth from a vendor site as Hypsocormus sp. (or a pachycormiform, at least) tooth, although the seller had listed it as plesiosaur. Thus it seems that confusion surrounding this topic is not uncommon. Unfortunately, however, my specimen is lacking its very apex (though, could this fact in itself be an indication of there once having been an acrodin tip that more easily got damaged or eroded away?)...

 

1353701567_PachycormiformfishtoothidentifiedasplesiosaurFlettonPeterborough01.jpg.d512fafd8c351cf8e2514c4305dea0a6.jpg755984909_PachycormiformfishtoothidentifiedasplesiosaurFlettonPeterborough02.jpg.0b8529956508bbaba852f0ec8b549225.jpg333569359_PachycormiformfishtoothidentifiedasplesiosaurFlettonPeterborough03.jpg.2a1cf5a7f8bc57bf192153f2d8bae1d2.jpg756241147_PachycormiformfishtoothidentifiedasplesiosaurFlettonPeterborough04.jpg.1ecb9caec76da798544d38009f0f3c53.jpg

 

Pachycormiform tooth mislabelled as plesiosaur, from Fletton, Peterborough

 

 

Size cannot be used as a distinguishing feature either, as, while my tooth's total length is 1'' or 2.54cm exactly, the enamelled part is only about 1.5cm, which seems to be close to the upper limit of what Hypsocormus sp. teeth were able to grow to, from what I've been able to find out. Ornamentation/striations then? This feature can't be used either, since not all positively identified pachycormiform teeth in my sample have these. How about an in-filled hollow root? Both have these. Though it seems that the pachycormiform teeth actually often lack the enamel-free part you'd identify as the root, with them apparently having broken off close to the enamelled crown, as is the case with most fish teeth. In fact, this was my main argument to reject my specimen being fish before. However, looking at the jaw posted above, you'll notice that the largest tooth lying next to the jaw does have an enamel-free, irregularly broken-off base as well.

 

I thus find myself wondering what the exact features are that define these pachycormiform teeth, and how to distinguish them from reptile teeth. Anybody have any ideas on this or on the argued identification of my tooth?

 

I'll start by tagging @PointyKnight, @RuMert, @caterpillar, @Carl and @taj, but please don't hesitate to join the discussion!

Edited by pachy-pleuro-whatnot-odon
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@fishguy@Pagurus

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11 minutes ago, caterpillar said:

In principle fish teeth have an acrodine cap

 

I know... But let it be exactly this part of the tooth that's no longer present :shrug:

 

Makes me wonder whether there are any differences in the preservational biases between acrodin versus enamel. For, if the latter has better chances of standing the test of time or if the former is more prone to pre-depositional damage, then the absence of the tooth apex in my specimen might be taken as evidence of the tooth having belonged to a fish...

 

May be @Fossildude19 would know more about acrodin and its potential preservational biases?

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'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

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Hi Alex,

my ideas, based on what I learned here on the forum, ended at striation and translucent tip (now I know thats the acrodine cap.)

Just some more thoughts: As there is a preservational bias against all pointed ends (sometimes counterbalanced by hardened tips, which evolution might again favour), I would see a bias against acrodine as only weak evidence.

Astonishing how similar these teeth are, maybe you have to look for microscopical or chemical hints?

Not only "is there striation", but "what exactly does it look like"?

For that you would need closeup references of confirmed samples.

Thats my grain of wisdom, good luck!

Best Regards,

J

 

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Thanks, Jan!

 

1 hour ago, Mahnmut said:

Astonishing how similar these teeth are

 

Yeah, I guess similar prey, similar teeth... Convergence of evolution and all that :P

 

It wouldn't be the first time I've had to tackle this problem either, as there are quite a number of fish with teeth that converge on those of marine reptiles (although, reptiles being secondarily aquatic, in reality, this statement should probably be the other way 'round :D) - my recent acquisition of a plioplatecarpine mosasaur tooth from the Pierre Shale in Kansas being a case in point (very similar to Pachyrhizodus sp.), as would the many confusions between reptile teeth and large predatory fish species like Enchodus sp. and Xiphactinus sp. (or Severnichthys acuminatus, for that matter). The difference with these cases, however, is that there are often enough clearly described morphological differences to base yourself off of, such as acrodin cap; patterns of striations; carination; shape of the base of the tooth crown; or, at worst, delimitation by size. These characters cannot be used here, as they're either absent in the morphologies being compared or are equatable between the clades.

 

1 hour ago, Mahnmut said:

As there is a preservational bias against all pointed ends (sometimes counterbalanced by hardened tips, which evolution might again favour), I would see a bias against acrodine as only weak evidence.

 

I agree that basing an identification on the assumption that a missing tip would be due to a missing acrodin cap is extremely weak evidence to say the least. It doesn't just require the making of an assumption as to preservational characteristics between acrodin and enamel, but, above all, falls back on the ancient trope that "absence of evidence is not evidence for absence". I.e., the fact that there's no acrodin cap doesn't mean that one would've been present.

 

1 hour ago, Mahnmut said:

maybe you have to look for microscopical or chemical hints?

 

Yet while I'm not quite sure how chemical analysis would work (nor am I willing to risk the tooth over its identification, at least not as long as there's no clear evidence to dismiss it being reptile), I have used microscopic analysis in the past, the aforementioned mosasaur tooth being my latest. I haven't yet put the current tooth under the microscope, but may be I should. It's a good suggestion. Thanks (now to see when I could find some time to do that :P)!

 

The biggest issue with doing so, however, is, as you yourself already pointed out, to get access to quality reference material so that such an analysis would make sense. Preferably I'd therefore acquire a larger specimen of Hypsocormus sp. or pachycormiform tooth with similar morphology to my tooth first, so that I'd have a reliable baseline to compare against. Moreover, ideally my comparison tooth would also come from Vaches Noires in order to rule out any preservational differences. And when all of these things are considered it actually turns into quite a list of demands for the analysis to have the potential of being fruitful... :shrug: Still, I know where I could get my hands on some smaller Kimmeridgian (I believe) teeth from the UK matching these requirements, so may be I should start with that.

Edited by pachy-pleuro-whatnot-odon

'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

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12 hours ago, pachy-pleuro-whatnot-odon said:

Hi all,

 

Last summer, while out hunting at the Vaches Noires on the Normandy coast of France, we found the below tooth in the Marnes de Dives (upper Callovian)

.1918080266_FieldphotoplesiosaurtoothVachesNoires.thumb.jpg.8b230f3bc8221435d2732cca42d66763.jpg

 

I extracted it from its matrix in order to be able to tell with confidence whether carinae are present or not and thus whether the tooth could be metriorhynchid - which I thought, at the time, to be the only other major contender. Carinae are not present. As such, I then arrived at the conclusion that the tooth is plesiosaurian, and in absence of striations - anastomosing or other - that it probably belonged to Cryptoclidus sp.. This is the state in which it has remained since then.

 

546521402_VachesNoirestoothscale.thumb.jpg.f599a8c3bb7d4e692e96424b73bc04fb.jpg1311559809_VachesNoirestoothlateral.jpg.b3bf92eeca9c0ff6e16d04243576ef21.jpg

 

1807248337_VachesNoirestoothlabial.jpg.1c4250da6bcaebdd0a6ddfbd3e885044.jpg303665721_VachesNoirestoothlingual.jpg.ebddf97a4fe8c53197d0cf0c8faaf131.jpg

 

1778605395_VachesNoirestoothbasal.thumb.jpg.6f707bb3dff28a10f2f13fadaf0c2acc.jpg1868496691_VachesNoirestoothapical.jpg.830278a259d042df04fec945ca7b6e82.jpg

 

601de60e87bca_oxfordclayplesiosaurteeth.jpg.f8aa95899493a585be843e6c31ce2ff9.jpg

From left to right: Muraenosaurus leedsi, Cryptoclidus oxoniensis and Tricleidus seeleyi (Noè, Taylor and Gómez-Pérez, 2017)

 

 

However, I keep occasionally bumping into Hypsocormus sp., a pachycormiform fish with a temporal range from the Callovian stage of the Middle Jurassic all the way through the Late Jurassic up to the Cretaceous - most recently today with the jaw below. And I must certainly say that I see some semblances...

 

1390851125_Hypsocormussp.fishjaw.jpg.15bfda0baaaa92a3a8dc374556976eaf.jpg

Specimen from the Oxford Clay at Peterborough

 

1073754422_Pachycormiformfishtooth.jpg.c7932d24ddfd695d66a08de4e4dd6351.jpg

An unidentified pachycormiform fish tooth from the Oxfordian levels of Vaches Noires (source) that I, here, suggest may, in fact, represent Hypsocormus sp..

 

990674877_HypsocormusfishtoothfromtheBolounnaisjden182.jpg.d087f5184d79c95317f7dd883a42b8ef.jpg1030042813_HypsocormusfishtoothfromtheBolounnaisjden186.jpg.1380c9bfabe1d3903f754524de300f42.jpg

 

Two specimens of Hypsocormus sp. from further up north on the French coast, in the Boulonnais, dating to the Kimmeridgian/Tithonian (source). Given sizes are 6.45mm and 13.1mm respectively.

 

302226060_HypsocormusteethfromtheLowerOxfordClay.thumb.jpg.4eefa146fab815c2dd0898fdd310c0e9.jpg

Two Hypsocormus sp. specimens from the Lower Oxford Clay, UK (specific locality unknown; source).

 

193596592_HypsocormusfishtoothfromtheTournusregionofSaneetLoire01.jpg.92d682de61ed3c750b84f787658e1d4d.jpg454869448_HypsocormusfishtoothfromtheTournusregionofSaneetLoire02.jpg.264d5b2faff03fd2443b8204637d8d79.jpg605771053_HypsocormusfishtoothfromtheTournusregionofSaneetLoire03.jpg.e30f94a616e9507224a304d7682247c2.jpg

 

Hypsocormus sp. from the Callovian of the Tournus-region of Saône et Loire in France (source).

 

One thing that stands out from all the specimens that I've been able to identify online is that most have an notable acrodin cap, which clearly marks them as fish teeth. It's based on this that I've identified the below tooth from a vendor site as Hypsocormus sp. (or a pachycormiform, at least) tooth, although the seller had listed it as plesiosaur. Thus it seems that confusion surrounding this topic is not uncommon. Unfortunately, however, my specimen is lacking its very apex (though, could this fact in itself be an indication of there once having been an acrodin tip that more easily got damaged or eroded away?)...

 

1353701567_PachycormiformfishtoothidentifiedasplesiosaurFlettonPeterborough01.jpg.d512fafd8c351cf8e2514c4305dea0a6.jpg755984909_PachycormiformfishtoothidentifiedasplesiosaurFlettonPeterborough02.jpg.0b8529956508bbaba852f0ec8b549225.jpg333569359_PachycormiformfishtoothidentifiedasplesiosaurFlettonPeterborough03.jpg.2a1cf5a7f8bc57bf192153f2d8bae1d2.jpg756241147_PachycormiformfishtoothidentifiedasplesiosaurFlettonPeterborough04.jpg.1ecb9caec76da798544d38009f0f3c53.jpg

 

Pachycormiform tooth mislabelled as plesiosaur, from Fletton, Peterborough

 

 

Size cannot be used as a distinguishing feature either, as, while my tooth's total length is 1'' or 2.54cm exactly, the enamelled part is only about 1.5cm, which seems to be close to the upper limit of what Hypsocormus sp. teeth were able to grow to, from what I've been able to find out. Ornamentation/striations then? This feature can't be used either, since not all positively identified pachycormiform teeth in my sample have these. How about an in-filled hollow root? Both have these. Though it seems that the pachycormiform teeth actually often lack the enamel-free part you'd identify as the root, with them apparently having broken off close to the enamelled crown, as is the case with most fish teeth. In fact, this was my main argument to reject my specimen being fish before. However, looking at the jaw posted above, you'll notice that the largest tooth lying next to the jaw does have an enamel-free, irregularly broken-off base as well.

 

I thus find myself wondering what the exact features are that define these pachycormiform teeth, and how to distinguish them from reptile teeth. Anybody have any ideas on this or on the argued identification of my tooth?

 

I'll start by tagging @PointyKnight, @RuMert, @caterpillar, @Carl and @taj, but please don't hesitate to join the discussion!

I certainly don't know plesiosaur teeth as well as I should and pachycormids even less. And anything I do know is centered on the US. But I think your reasoning is very sound. My gut says this is way more fishy than reptilian. And even though the tip is missing, I think it's very reasonable that the acrodin tip just snapped off. Nice find wither way!

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I'd say plesiosaurian teeth are more curved and slender - besides that a-cap. Maybe there's a difference in the root and the root canal? They say fish teeth grow directly from the jaw

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3 hours ago, RuMert said:

I'd say plesiosaurian teeth are more curved and slender

 

As a general trend, you might have a point there - although visual comparison against confirmed plesiosaur teeth in my collection shows that the curvature of this tooth still falls within the acceptable range, albeit probably a bit of an outlier.

 

3 hours ago, RuMert said:

Maybe there's a difference in the root and the root canal? They say fish teeth grow directly from the jaw

 

That's also what I thought (that fish teeth grow straight from the jaw). So when I found what looked like a root-structure I took this as significant evidence for the tooth being plesiosaurian rather than fish. And, indeed, in most specimens referenced above you'll observe a root is lacking. However, when you look at this jaw I posted, then the teeth there have what does look like a root, which is horribly confusing. But the fact that fish teeth are so often found without root and are said to grow directly from the jaw is indeed what made me think there might be some difference in the roots between fish and reptile teeth. Although how to find out and establish the exact nature of these differences is going to be difficult, as this will likely require analysis of confirmed specimens on either end.

 

I've since bought some reference teeth and might actually acquire some larger ones as well, so that I'll hopefully have something to compare against.

'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

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7 hours ago, pachy-pleuro-whatnot-odon said:

That's also what I thought (that fish teeth grow straight from the jaw). So when I found what looked like a root-structure I took this as significant evidence for the tooth being plesiosaurian rather than fish.


There are some bony fish with rooted teeth. Xiphactinus and Bluefish are two that come to mind. Elasmo.com has a nice example of a rooted wahoo tooth from the Pliocene.

 

 

FE66F93E-E5D1-43FD-ABFD-61CD1FBEF973.jpeg

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I definitely support the ID as a pachycormid fish. It appears as if there is some very slight apical constriction, regardless of the lack of the very tip. Overall, the tooth seems circular in cross section, less elliptical than expected for a cryptoclidid. For Cryptoclidus with its gracile teeth specifically this would also be very robust, plus it lacks any kind of typical Cryptoclidus ornamentation.

In size, shape, coloration, and enamel structure it definitely seems exceedingly similar to the pachycormid teeth in my collection. As for maximum size, there might be some room since the largest teeth in the Oxford Clay 'Hypsocormus' are missing and specimens are so rare and incomplete. Still, the broken roots indicate some massive teeth. Speaking of, there is actually no Callovian Hypsocormus in the Oxford Clay and corresponding formations: As of Maxwell et al. 2020 "Re-evaluation of pachycormid fishes from the Late Jurassic of Southwestern Germany", it's restricted to the Kimmeridgian-Tithonian. 'Hypsocormus' tenuirostris from the OC is closest to Orthocormus and may be congeneric with it, and 'Hypsocormus' leedsi is too fragmentary to be identified at a genus level. I think the ID as a pachycormid is very likely!

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Way above my head here , but I enjoy the conversation ! :popcorn:

I will have to take a look at my VN teeth once I have unpacked the boxes ....

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23 hours ago, PointyKnight said:

I definitely support the ID as a pachycormid fish. It appears as if there is some very slight apical constriction, regardless of the lack of the very tip. Overall, the tooth seems circular in cross section, less elliptical than expected for a cryptoclidid. For Cryptoclidus with its gracile teeth specifically this would also be very robust, plus it lacks any kind of typical Cryptoclidus ornamentation.

In size, shape, coloration, and enamel structure it definitely seems exceedingly similar to the pachycormid teeth in my collection. As for maximum size, there might be some room since the largest teeth in the Oxford Clay 'Hypsocormus' are missing and specimens are so rare and incomplete. Still, the broken roots indicate some massive teeth. [...] I think the ID as a pachycormid is very likely!

 

Thanks, Mien! Yeah, I agree that it seems increasingly likely that this is actually a pachycormiform tooth, rather than a plesiosaurian one. As you said, from what I've seen, it matches up quite nicely in terms of shape, colour, enamel structure and even size. With respect to the latter, I just bought a pachycormiform tooth earlier today that, while not having a root, still has an acrodin tip and measures close to the crown-height of my tooth. Interestingly, it's a Callovian tooth, whereas the rest of the pachycormiform teeth I expect to arrive over the next few weeks are indeed Kimmeridgian in age (most of them very small, albeit one is larger and with a root, like mine). It'll be interesting to compare these teeth to mine, once they've come in... However, between my own investigation and your experience of Oxford Clay teeth, I suspect you'll prove right. Especially your observation of the slight apical constriction is a convincing argument.

 

What made this a difficult question for me to answer, though, was that I don't actually have that many Callovian teeth in my collection, let alone plesiosaurian ones, and that in terms of robustness and curvature the tooth still fits within the morphologies seen in both younger (Upper Jurassic and above) and older (Triassic and Lower Jurassic) plesiosaurian teeth in my collection, so that one would expect such a morphology to not be out of place in the Callovian either. And, in fact, while Muraenosaurus leedsi does have rather compressed teeth, specimens of Tricleidus seeleyi I've seen have less so - which matches the diagram provided by Noè, Taylor and Gómez-Pérez (2017), included above. As such, in absence of any real cryptoclidid teeth either in my personal collection or in the museums I've visited around me (while those in the Senckenberg Museum in Frankfurt are at least at a studiable height, they are reproductions, yet appear unornamented and uncompressed), aforesaid diagram has been the best I could do in terms of determining how a cryptoclidid tooth is supposed to look (those of the Seeleyosaurus guilelmiimperatoris in the Museum am Löwentor could, by extension, be considered another reference, though not a cryptoclidid and hard make out details from). Therefore, the way I read the diagram, these teeth have negligible compression, with little to no ornamentation (depending on how you interpret the hatchings at the start of the tooth crown in this drawing) - something that matches both the cryptoclidid specimens I've seen and that of Seeleyosaurus. So when you say my tooth lacks the typical Cryptoclidus-ornamentation, I'm a bit confused, as it was my impression they didn't have any...

 

826958254_ReproducedCryptoclidusoxoniensisskullanddentition01.thumb.jpg.3fb64a1f062ea590895c93c90c66a513.jpg746115189_ReproducedCryptoclidusoxoniensisskullanddentition02.thumb.jpg.df55b83bd5a666785000bffc6de96bf6.jpg47682128_ReproducedCryptoclidusoxoniensisskullanddentition03.thumb.jpg.8f5961025ad8cdac63d3e073c6635b8e.jpg

 

Cryptoclidus oxoniensis reproduced skull and dentition at the Senckenberg Museum in Frankfurt

 

 

853847756_HeadanddentitionofSeeleyosaurus.thumb.jpg.8999665b387380c2fa9973acf43db7a5.jpg

Seeleyosaurus guilelmiimperatoris at the Museum am Löwentor in Stuttgart

 

23 hours ago, PointyKnight said:

Speaking of, there is actually no Callovian Hypsocormus in the Oxford Clay and corresponding formations: As of Maxwell et al. 2020 "Re-evaluation of pachycormid fishes from the Late Jurassic of Southwestern Germany", it's restricted to the Kimmeridgian-Tithonian. 'Hypsocormus' tenuirostris from the OC is closest to Orthocormus and may be congeneric with it, and 'Hypsocormus' leedsi is too fragmentary to be identified at a genus level.

 

In any case it's good to know Hypsocormus is not actually recognized from the Callovian of the Oxford Clay, which probably explains why the one single tooth from the Vaches Noires I was able to find as a reference is probably referred to as "pachycormiformes indet.".

'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

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  • 3 weeks later...

So, got my final batch of fish teeth in last week, and finally found some time to put the biggest and best of these under the microscope for comparison with my tooth. The first thing to note is the huge size difference. While the tooth shown for comparison - a pachycormid cf. Hypsocormus tooth from the Callovian Lower Oxford Clay of Peterborough - is the largest tooth of this type I could get my hands on, and stands out above the rest, it pales in size compared to my tooth from the Vaches Noires, which crown is not only nearly twice as big, but certainly as many times as massive as well.

 

1535907586_Pachycormidfishteeth.thumb.jpg.e8d6e917493f133bc4b3411546421c21.jpg

 

As Mien pointed out above, however, size need not necessarily be diagnostic, as large pachycormiform teeth have been reported. What's more, one of my British contacts who does a lot of collecting from the Oxford Clay told me he has personally found fangs as tall as 22mm and has heard of them reaching up to 35mm (although it's unclear as to whether these include the root-part or not), which approximates the size of my tooth, if not goes beyond it.

 

Morphologically, the pachycormiform teeth identified as Hypsocormus (whether actually from the Kimmeridgian or earlier 'Hypsocormus' variants) seem a decent match too, since they are all pointy and conical with varying degrees of curvature, into which the curvature of my find comfortably fits. Interestingly, however, the Kimmeridgian specimens I have available for study show some mild degree of unidirectional compression, which my tooth doesn't have. Nor does the Callovian tooth illustrated above. However, that one, in contrast, has one flattened side (presumably the labial face) and an imperfect circular cross-section. Again my tooth doesn't have this.

 

Another point of comparison is the presence or absence of an acrodin cap: my Callovian reference specimen has one, but the Kimmeridgian ones seemingly don't (although this could be an artefact of their much smaller size). When trying to detect whether my own find had an acrodin tip by looking for a constriction towards the tooth apex, I fail to find any clear indication. Instead, it appears that the missing enamel at the tip has exposed the underlying dentine, which causes the apex to look like it has a small bump on top, with constriction being suggested where enamel is missing around the edge of it.

 

1279304791_Small-pachycormid-cf.-Hypsocormus-sp.-tooth-acrodin-tip-01.jpg.c854d0440e10e6a9892ea1212f01d209.jpg2146278265_Small-pachycormid-cf.-Hypsocormus-sp.-tooth-acrodin-tip-02.jpg.d1d2ac03788253745d4f538b65988479.jpg

 

Acrodin cap on the pachycormid/'Hypsocormus' fish tooth from the Callovian of Peterborough

 

 

2018323741_VN-pachycormid-cf.-Hypsocurmus-sp.-fang-tip-detail-01.jpg.fe1f6c6a815c1a25b5dbdfa193c06814.jpg

Apex of the tooth found at Vaches Noires

 

 

 

Next, looking at the enamel there is a certain similarity between the confirmed pachycormid fish teeth and my find: both have fine vertical striations that seem at points to vermiculate. Moreover, colour, refraction and the gradual transition between root and crown are similar in both.

 

1002493482_Small-pachycormid-cf.-Hypsocormus-sp.-tooth-enamel--root-detail.jpg.269491917528db54fcaeaf631f06af4b.jpg

Details of root and enamel on the pachycormid/'Hypsocormus' fish tooth from the Callovian of Peterborough

 

 

4027889_VN-pachycormid-cf.-Hypsocurmus-sp.-fang-enamel-detail-01.jpg.fa67994fabf2b7e5ecd2ae39e1146858.jpg1047706174_VN-pachycormid-cf.-Hypsocurmus-sp.-fang-enamel-detail-02.jpg.60b90ff27d3148b4c1312dc8adfb150f.jpg

 

Details of the enamel of the tooth found at Vaches Noires

 

 

The last line of evidence that I looked into is some strange rib-like structures I found on the root of the tooth I found. And while none of my reference Hypsocormus-teeth preserve a root structure to compare to, their presence seems odd for a plesiosaur root (nor is it prominent enough to be ichthyosaurian, before anybody asks). Have a look below:

 

543969064_VN-pachycormid-cf.-Hypsocurmus-sp.-fang-crown-root-transition-detail.jpg.88fc50b48cd88ea5c10c62d7b61ec210.jpg232658022_VN-pachycormid-cf.-Hypsocurmus-sp.-fang-root-detail-01.jpg.bc2ae3fc21fa91ce45ff635de6b965ee.jpg

 

825566405_VN-pachycormid-cf.-Hypsocurmus-sp.-fang-root-detail-02.jpg.3fd2c1978cc3fbdf157612ccb40edf73.jpg

 

 

Considering all the above-mentioned morphological similarities between pachycormid (esp. cf. Hypsocormus, whether with or without quotation-marks) teeth and the one I found, and in particular the correspondence in features of the enamel, I believe the case can be closed with the tooth being identified as "pachycormidae indet. cf. Hypsocormus". What's more, I recently received a partial Cryptoclidus sp. tooth, which allowed me to compare levels of compression as well as ornamentation and also establish significant differences with the tooth I found. Yet, even though a fish tooth, at this size it's certainly an uncommon if not rare find, so I'm still happy with it (plus it provided me an educational nice little study project)! :)

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'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

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  • 3 weeks later...

Hey Pachy , you want to get back there , better hurry up ! The last ( and final ) draft of the proposed protection plan for the Normandy coast has been released . And surprise , surprise , it's a total ( and unexpected ) reversal of the former drafts . Total ban on collecting on the proposed protected areas ( whatever , whenever , wherever) .So better hurry up before law is enacted ( 2023) ....You've got to love french administration .

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20 hours ago, taj said:

Hey Pachy , you want to get back there , better hurry up ! The last ( and final ) draft of the proposed protection plan for the Normandy coast has been released . And surprise , surprise , it's a total ( and unexpected ) reversal of the former drafts . Total ban on collecting on the proposed protected areas ( whatever , whenever , wherever) .So better hurry up before law is enacted ( 2023) ....You've got to love french administration .

 

Oh no! Seriously? :( I mean, with quarries in the Low Countries having become inaccessible (with some minor exceptions), the quarries in and around the Posidonia Shale in Southern Germany getting depleted, the NSR being flooded and things like this seemingly happening all over the world, it really feels like the age of avocational palaeontology is fading fast - in any case here in Europe, where the age of quarrying generally seems to (mostly) be a thing of the past - or, at the very least, tolerance of collectors and palaeontologists in quarries.

 

But I thought that at least coastal sites would be safe insofar as they wouldn't be blocked from eroding by the construction of coastal defences... Now you're telling me that one of the most important ones this side of The Channel is going to be made off limits to collection? But, I mean, what's the big deal with simply picking up an already loose fossil that's going to be eroded away otherwise anyway? The British seem to understand this very well with their fossil collectors' Code of Conduct. To me a law prohibiting any fossil collection at Vaches Noires just sounds like law-makers have no understanding of the situation, nor local law-enforcement the desire to differentiate and monitor between tolerated fossil collection and illegal excavation. It's like "we tried to be tolerant, but things occasionally go wrong, so lets just put an end to all of this lest we need to start putting any regulatory effort". Now plenty of people visit the Normandy coast and Vaches Noires for other reasons as well, but I wonder whether they've given any thought to how this will impact local tourism, much of which, at least in part, focusses on fossil collection...

 

I really need to give this some thought. This is absolutely the worst year for me to find time to still go on a fossil hunt. And even if I would, for how long could and would I go? How big are the chances of my finding marine reptile bones there that would be the main aim of collection trip? Especially with all the shells I've already gotten from Vaches Noires and the bags of material I still need to prep... This is such disappointing news! But thanks for letting me know in any case! At least this gives me a chance to still visit the site before it's too late! :(

 

Do you know when the law comes into force? Is it just a law local to the department, or does it affect all French coastal sites, such as those in the Boulonnais as well? And if just Normandy, does it affect all stretches of coast? Are parts of it still available to collecting? How would you know where you can collect and where it's prohibited? So many questions, all such a pity... :(

'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

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All the good seaside sites between Honfleur and Caen . How is it called cote d'opale, cote fleurie ?  Here is the link for the detailed areas that are in the scope of this project https://www.normandie.developpement-durable.gouv.fr/projet-de-creation-d-une-reserve-naturelle-a4158.html?fbclid=IwAR2XEDCRKkCe9pWTjyEKYcEY-BxyF5QgtkyuRCeHAhM-gwoAl6cjafc7wuY.

 

The guys behind this last twist are from University of Caen, so they don't (care) about whatever consequences. In fact they have set their aim higher and plan to expand the same scheme to the whole region of Normandie .So more fun to come . Due date is something into 2023 , not much details now .

Vive la France !image.thumb.png.ff40d7e2870f6ceb9252d67b4f326e3f.png

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hum , I had a last look on the project and I have to make a correction : it does not stop at Caen but goes far beyond toward Cherbourg....

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Thanks for the link. I'll have a look at it and check out the details :Smiling:

 

So it's the University of Caen that's behind this? No doubt that'll still be allowed to collect from those protected beaches? Competition get a bit much for them? I've said it before, but they should've just taken an example in the Charmouth Heritage Center, where you're obliged to report significant finds, but are otherwise just allowed to collect just like that. A much better system, I think as most people are perfectly willing to work along with such a scheme, whereas the Normandy-proposal will likely only trigger illegal collecting :(

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'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

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This is France for you Pachy , why start thinking things over when you can just ban everything ? Officially it 's the french administration , under the guise of the DREAL , sanctioned by the prefect of Normandy ( who will be responsible for publishing the final decrees ) who are the acting parties involved . But of course they rely on a body of " experts" to prepare the draft . It looks like these expert think the best way to protect is to ban . Of course the concept of " protecting " anything that sits on the foreshore is completely ludicrous , but hey , why not try something new ? BTW the former legislators had a bit more sense ,and they understood that anything on the foreshore is doomed to quick destruction by the tides . That's why they come with the legal concept of the foreshore ( Domaine Public Maritime ) ,which ,as the name says , is one of the very few exception in the french law in terms of ownership : it cannot belong to a private party , not does it belong to the state .So you are free to roam it and collect anything that you might find here . But that was before . 

Quite a bit of venting ,I'm afraid ,but I 'm pretty ##### off by that project : on top of being a gorgeous and plentiful spot , it was also one of the very few spots where you could bring in your kids and share a good time . Whether they would look for fossils with you or tire out and start chasing crabs and shrimps in the nearby pools . 

 

PS : and oh yes it will be the usual stuff with permits delivered to scientific institutions so probably they will still get a free pass which they won't use because 

1/ the will probably prefer sitting in for of their computers or chase the existing fossils in the keeps of museums 

2/ the heydays of the VN are long past .This is a very old site ( cf Flaubert in Bouvard et Pecuchet) and the civils works on the coast in the 60 s have caused the better layers to be more or less completely covered by sand now . So much for the possibility of finding exceptional stuff " museum worthy "

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17 hours ago, taj said:

This is France for you Pachy , why start thinking things over when you can just ban everything ? Officially it 's the french administration , under the guise of the DREAL , sanctioned by the prefect of Normandy ( who will be responsible for publishing the final decrees ) who are the acting parties involved . But of course they rely on a body of " experts" to prepare the draft . It looks like these expert think the best way to protect is to ban . Of course the concept of " protecting " anything that sits on the foreshore is completely ludicrous , but hey , why not try something new ? BTW the former legislators had a bit more sense ,and they understood that anything on the foreshore is doomed to quick destruction by the tides . That's why they come with the legal concept of the foreshore ( Domaine Public Maritime ) ,which ,as the name says , is one of the very few exception in the french law in terms of ownership : it cannot belong to a private party , not does it belong to the state .So you are free to roam it and collect anything that you might find here . But that was before . 

Quite a bit of venting ,I'm afraid ,but I 'm pretty ##### off by that project : on top of being a gorgeous and plentiful spot , it was also one of the very few spots where you could bring in your kids and share a good time . Whether they would look for fossils with you or tire out and start chasing crabs and shrimps in the nearby pools.

 

Yeah, our five year old son really enjoyed our week there last summer. So much so, in fact, that he's decided that what he'd like to be come when he grows up is "someone who looks for fossils and sells them in a store", as he himself puts it. It'll be hard to tell him that soon the great time he had there will be a thing of the past :(

 

17 hours ago, taj said:

PS : and oh yes it will be the usual stuff with permits delivered to scientific institutions so probably they will still get a free pass which they won't use because 

1/ the will probably prefer sitting in for of their computers or chase the existing fossils in the keeps of museums 

2/ the heydays of the VN are long past .This is a very old site ( cf Flaubert in Bouvard et Pecuchet) and the civils works on the coast in the 60 s have caused the better layers to be more or less completely covered by sand now . So much for the possibility of finding exceptional stuff " museum worthy "

 

And, by the sound of it, due to a bunch of "experts" who'd rather see things destroyed rather than work together with amateur collectors. Such a pity! I absolutely hope this idea doesn't spread to other departments and that they'll moreover come to their senses before too long, may be reverse their new policies. I guess one can only hope (though, I must admit, policies like this are way less likely to reverse as are those that are the inverse of it - i.e., the ones explicitly allowing collection) :fingerscrossed:

'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

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From discussions on Steinkern , with knowledgeable German members fond of the VN , the programmed date for the new rules is december 2023 . so you still have 2 summers to go there , Pachy !

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3 hours ago, taj said:

From discussions on Steinkern , with knowledgeable German members fond of the VN , the programmed date for the new rules is december 2023 . so you still have 2 summer to go there , Pachy !

 

Thanks for having looked into that! That at least gives some breathing space! :notworthy:

'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

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Drives me mad to see backwards regulations like that, I feel for you guys over at the other side of the pond.

Anyone on this forum probably has had this thought already, but to rant to the wind, laws that outright ban collecting for the sake of "conserving fossils" are doing exactly the opposite of fossil conservation. Nature's grindstone is merciless, and any surface fossil not picked up by a collector or academic is doomed to erode away into nothingness. Erosion is not a hard concept to grasp, this shouldn't be a shock to any common person, let alone a "panel of experts". I wonder what would be the efficacy of petitioning... would a popular petition have much of an effect in France? What else could one do?

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“Not only is the universe stranger than we think, it is stranger than we can think” -Werner Heisenberg 

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France is becoming a nightmare for us, amateurs in paleontology.

I have another example of an outcrop of vertebrate fossils ban in south of france.

They prefer to have the fossils destroyed by erosion rather than saved by non professionals. Moreover, they already have hundreds of these fossils but they are in a delirium to forbid eveything. And these few professional paleontologists are very agressive, they wont hesitate to sue you.

In a word : sad for everyone.

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