Mosasaur tooth with bitemark?

[Sofyar]

Hey guys,

I just bought a relatively large Mosasaur tooth and I found what I believe to be another Mosasaur tooth mark near the base of the tooth, but I wasn't sure. Tell me what you think! Second picture I circled what I believe is the tooth damage. 

[Praefectus]

That's an interesting looking tooth. I don't think the spot you pointed out is a bite mark. More likely the damage occurred during the fossilization process or when the tooth was found and extracted from the phosphate quarries.

 

 

@pachy-pleuro-whatnot-odon Here is an interesting mosasaur topic you might be interested in. 

[Sofyar]

36 minutes ago, Praefectus said:

That's an interesting looking tooth. I don't think the spot you pointed out is a bite mark. More likely the damage occurred during the fossilization process or when the tooth was found and extracted from the phosphate quarries.

 

 

@pachy-pleuro-whatnot-odon Here is an interesting mosasaur topic you might be interested in. 

I see. I thought it looks too old to be recent damage and the surface on the damaged part looks like it was fossilized itself. I will follow the topic you sent!

[Praefectus]

Curiously, could you send a more centered photo of the tooth? It looks like its one of the rare species from Morocco.

 

19 minutes ago, Sofyar said:

I will follow the topic you sent!

??? I didn't send a topic.  I was just tagging Alexander incase he was interested in taking a look. 

[Sofyar]

1 hour ago, Praefectus said:

Curiously, could you send a more centered photo of the tooth? It looks like its one of the rare species from Morocco.

 

??? I didn't send a topic.  I was just tagging Alexander incase he was interested in taking a look. 

I will.Oh and I thought it was a topic for me to follow haha. This is a nicer photo of the tooth

[abyssunder]

Nice tooth!

Can you post a picture more focused on the area in question?

Thank you!

[pachy-pleuro-whatnot-odon]

In general, there can be many reasons for cuts, gouges, gashes and scratches on bone and teeth, though it can be difficult to unambiguously define them as signs of predation. Sets of parallel grooves and rows of aligned circular depressions are commonly considered the clearest evidence, although the latter marks may, in fact, be attributable to limpets. When it comes to that, some of the most undeniable evidence for predation in marine reptiles I've seen comes in the form not of circular, but of triangular marks, such as the one on the distal end of a pliosaur podial below, as this could only have been made by the (sub)trihedral teeth of another pliosaur.

 

 

Trihedral tooth of Pliosaurus sp. from the Lower Cretaceous of Crimea (figure 2 from Zverkov 2015)

 

In addition to this kind of predation damage, teeth can have worn-down tips considered feeding damage; smoothed sides or missing enamel near the apex from occlusional damage (teeth rubbing past each other); or even enamel peeling (bits of enamel missing), presumed to again be caused by feeding (in essence a form of pressure-flaking). But unless these areas are smoothed down on an otherwise crisp tooth, it's hard to conclusively tie this in with feeding, since, as far as I'm aware, enamel peeling can also occur post-mortem in the tooth's depositional context by pressures within the tooth building up as sedimentary layers build up on top of it. This is the case with a plesiosaur tooth I found last summer and that I carefully extracted from the matrix it was found it: when I got it out, the very tip appeared to be missing and worn down (and not present in the matrix), whereas lower down the lingual side of the tooth a bit of enamel had peeled off that I also did not notice in the matrix, even though I had extracted the tooth with great care and it otherwise came out cleanly. My interpretation is thus that this tooth shows evidence of both feeding damage at the tip and geological pressure at its inside curve.

 

 

All this to say, though, that it's hard to say whether the spot on your tooth is a predation mark or not. However, I agree with Trevor that it's not very likely, seeing as the damage on your tooth is rather common on certain types of mosasaur teeth (particularly the larger ones with less ornamentation, it seems). Some of it is certain to be the result of the fossilization process (as with my plesiosaur tooth above, where pressure on the tooth caused a chip to pop off), while other damage may have been caused either at discovery or during preparation (it wouldn't be the first time a fossil or artefact was found by hitting it with an excavation tool, leaving a lasting mark). In any case, the below thread may be of interest:

 

 

5 hours ago, Praefectus said:

Curiously, could you send a more centered photo of the tooth? It looks like its one of the rare species from Morocco.

 

As to the species: with the new photographs I'm thinking tylosaurine, although possibly you were thinking of something else, Trevor?

[LordTrilobite]

As can be seen in my old thread that @pachy-pleuro-whatnot-odon linked, these types of wear patterns are all near identical. Very common on bigger Prognathodon teeth. They are always on the front on the lower half like this. Since these patterns are all nearly the same I think it's where the teeth occlude and abrade to create these types of wear patterns.

So yes, you could say it is a bite mark. But a bite mark from the animal itself.

[Sofyar]

1 hour ago, abyssunder said:

Nice tooth!

Can you post a picture more focused on the area in question?

Thank you!

This is the closest my phone camera allows and stays in focus haha. I'll try to take a better picture with a better phone.

[Sofyar]

7 minutes ago, LordTrilobite said:

As can be seen in my old thread that @pachy-pleuro-whatnot-odon linked, these types of wear patterns are all near identical. Very common on bigger Prognathodon teeth. They are always on the front on the lower half like this. Since these patterns are all nearly the same I think it's where the teeth occlude and abrade to create these types of wear patterns.

I see. Thanks for your answer!

[Sofyar]

20 minutes ago, pachy-pleuro-whatnot-odon said:

In general, there can be many reasons for cuts, gouges, gashes and scratches on bone and teeth, though it can be difficult to unambiguously define them as signs of predation. Sets of parallel grooves and rows of aligned circular depressions are commonly considered the clearest evidence, although the latter marks may, in fact, be attributable to limpets. When it comes to that, some of the most undeniable evidence for predation in marine reptiles I've seen comes in the form not of circular, but of triangular marks, such as the one on the distal end of a pliosaur podial below, as this could only have been made by the (sub)trihedral teeth of another pliosaur.

 

 

Trihedral tooth of Pliosaurus sp. from the Lower Cretaceous of Crimea (figure 2 from Zverkov 2015)

 

In addition to this kind of predation damage, teeth can have worn-down tips considered feeding damage; smoothed sides or missing enamel near the apex from occlusional damage (teeth rubbing past each other); or even enamel peeling (bits of enamel missing), presumed to again be caused by feeding (in essence a form of pressure-flaking). But unless these areas are smoothed down on an otherwise crisp tooth, it's hard to conclusively tie this in with feeding, since, as far as I'm aware, enamel peeling can also occur post-mortem in the tooth's depositional context by pressures within the tooth building up as sedimentary layers build up on top of it. This is the case with a plesiosaur tooth I found last summer and that I carefully extracted from the matrix it was found it: when I got it out, the very tip appeared to be missing and worn down (and not present in the matrix), whereas lower down the lingual side of the tooth a bit of enamel had peeled off that I also did not notice in the matrix, even though I had extracted the tooth with great care and it otherwise came out cleanly. My interpretation is thus that this tooth shows evidence of both feeding damage at the tip and geological pressure at its inside curve.

 

 

All this to say, though, that it's hard to say whether the spot on your tooth is a predation mark or not. However, I agree with Trevor that it's not very likely, seeing as the damage on your tooth is rather common on certain types of mosasaur teeth (particularly the larger ones with less ornamentation, it seems). Some of it is certain to be the result of the fossilization process (as with my plesiosaur tooth above, where pressure on the tooth caused a chip to pop off), while other damage may have been caused either at discovery or during preparation (it wouldn't be the first time a fossil or artefact was found by hitting it with an excavation tool, leaving a lasting mark). In any case, the below thread may be of interest:

 

 

 

As to the species: with the new photographs I'm thinking tylosaurine, although possibly you were thinking of something else, Trevor?

I will check out the thread! Thank you very much for the informative answer! I also recently got a Mosasaur rib with markings that have been identified as a shark teeth mark. I can send a picture if you want. 

[pachy-pleuro-whatnot-odon]

9 minutes ago, Sofyar said:

I will check out the thread! Thank you very much for the informative answer! I also recently got a Mosasaur rib with markings that have been identified as a shark teeth mark. I can send a picture if you want. 

 

Was that specimen from Gove County, Kansas? If so, I think I've seen that up for sale, and now know who beat me to it

 

But, yeah, if you've got additional photographs, I'd certainly be interested

Edited November 11, 2021 by pachy-pleuro-whatnot-odon

[Praefectus]

1 hour ago, pachy-pleuro-whatnot-odon said:

As to the species: with the new photographs I'm thinking tylosaurine, although possibly you were thinking of something else, Trevor?

Yes, I was thinking tylosaurine too. A nice one too. 

[pachy-pleuro-whatnot-odon]

15 hours ago, LordTrilobite said:

So yes, you could say it is a bite mark. But a bite mark from the animal itself.

 

In hopes of providing a balancing alternative opinion, I'm more reserved when it comes to the interpretation of the gauge as occlusional damage. Much like in archaeology and forensic science the cuts and bumps on bone may be differently interpreted based on shape, size, edge morphology, position, etc., I find this mark to be positioned rather far down near the base of the crown (you'd expect occlusion to be more frequent towards the tip), oddly slanted (imagine the angle at which the opposing tooth would have had to stand to create a gash like that), and very deep (the opposing tooth would've had to stand very close to this one). I also find that the edges of the cut look a bit too sharp, more like the result of an incidental event rather than the repeated wear of occlusion. If occlusional damage, I'd rather expect a smoothed, rubbed down spot, as in the brachauchenine pliosaur tooth from Stary Oskol below:

 

 

Then again, different species, different dental characteristics. Striations help strengthen a tooth, especially against the stresses of underwater feeding. So it's possible that occlusional wear on pair teeth would on different than in mosasaurs. Then again, with damage being so common in prognathodontids - which teeth exhibit some durophagous adaptations - one wonders whether these exact durophagous adaptations would not have protected the teeth against such wear?

 

In case of the tooth under consideration here, though, I think the position, angle, depth and roughness of the edges point towards incidental damage. And while it could very well be the gauge was caused by the opposing tooth being pushed out of the jaw as the replacement tooth grew, it also seems possible time that the cut was made by something the mosasaur bit on, such as a piece of bone pushed into the tooth with a chunk of meat while the mosasaur was eating, or a hard shell... Just a thought.

Edited November 12, 2021 by pachy-pleuro-whatnot-odon

[Sofyar]

On 11/12/2021 at 4:14 PM, pachy-pleuro-whatnot-odon said:

 

In hopes of providing a balancing alternative opinion, I'm more reserved when it comes to the interpretation of the gauge as occlusional damage. Much like in archaeology and forensic science the cuts and bumps on bone may be differently interpreted based on shape, size, edge morphology, position, etc., I find this mark to be positioned rather far down near the base of the crown (you'd expect occlusion to be more frequent towards the tip), oddly slanted (imagine the angle at which the opposing tooth would have had to stand to create a gash like that), and very deep (the opposing tooth would've had to stand very close to this one). I also find that the edges of the cut look a bit too sharp, more like the result of an incidental event rather than the repeated wear of occlusion. If occlusional damage, I'd rather expect a smoothed, rubbed down spot, as in the brachauchenine pliosaur tooth from Stary Oskol below:

 

 

Then again, different species, different dental characteristics. Striations help strengthen a tooth, especially against the stresses of underwater feeding. So it's possible that occlusional wear on pair teeth would on different than in mosasaurs. Then again, with damage being so common in prognathodontids - which teeth exhibit some durophagous adaptations - one wonders whether these exact durophagous adaptations would not have protected the teeth against such wear?

 

In case of the tooth under consideration here, though, I think the position, angle, depth and roughness of the edges point towards incidental damage. And while it could very well be the gauge was caused by the opposing tooth being pushed out of the jaw as the replacement tooth grew, it also seems possible time that the cut was made by something the mosasaur bit on, such as a piece of bone pushed into the tooth with a chunk of meat while the mosasaur was eating, or a hard shell... Just a thought.

 

On 11/12/2021 at 2:23 AM, Praefectus said:

Yes, I was thinking tylosaurine too. A nice one too. 

Interesting. Could be the new tooth pushing the old, but considering the fact the tooth has like no feeding wear I think it unlikely the tooth stayed in the mouth long enough to be pushed out of it by a new one so I think that is something to consider. The idea it was maybe feeding on a shelled animal that damaged the tooth seems more likely actually, a big Ammonite or maybe even an Archelon, I mean the tooth is big almost 6.5 Centimeters long (about 2.5 inches) that means the specimen must have been around 10 meters long maybe even bigger so more than capable of attacking the huge sea turtle.

Edited December 3, 2021 by Sofyar

[Sofyar]

Also if we are in the midst of discussing teeth damage I recently got hold of a Mosasaur rib with Shark teeth damage. Here it is. 

[pachy-pleuro-whatnot-odon]

26 minutes ago, Sofyar said:

Also if we are in the midst of discussing teeth damage I recently got hold of a Mosasaur rib with Shark teeth damage. Here it is. 

 

Yeah that's the one I saw and I missed out on buying...!  Beautiful specimen! 

[Troodon]

I'm not in the camp thats says its a bite mark.  Looks to irregular.  Always a difficult call.

[Sofyar]

14 minutes ago, pachy-pleuro-whatnot-odon said:

 

Yeah that's the one I saw and I missed out on buying...!  Beautiful specimen! 

I'm sorry haha. thanks though! 

[Sofyar]

2 minutes ago, Troodon said:

I'm not in the camp thats says its a bite mark.  Looks to irregular.  Always a difficult call.

tooth or rib? or both?

[pachy-pleuro-whatnot-odon]

20 minutes ago, Troodon said:

I'm not in the camp thats says its a bite mark.  Looks to irregular.  Always a difficult call.

 

17 minutes ago, Sofyar said:

tooth or rib? or both?

 

I think this refers to the rib, and I agree. There could be any number of reasons for such a depression, although it does look like an ancient mark. Still, the rib itself is very nice example, and it would've been very interesting to study the mark in person...

[Troodon]

Rib .and yes its very nice.   Predation marks are extremely difficult to definitively call.  I would expect a tooth mark to be straight and not zigzag

[Sofyar]

On 12/3/2021 at 7:02 PM, pachy-pleuro-whatnot-odon said:

 

 

I think this refers to the rib, and I agree. There could be any number of reasons for such a depression, although it does look like an ancient mark. Still, the rib itself is very nice example, and it would've been very interesting to study the mark in person...

Sorry for the very late response haha. 

I did take a closer examination and compare it to other fossils with bite marks and I will say it's very hard to determine but the mark itself was not made recently that is for certain. But considering other parameters like the size of the rib, we can determine the specimen in question was still a "teen" and probably susceptible to shark attacks. Now the shape of the mark is not "straight" but I would not go as far as to call it zigzagi, but would love to know what you make out if it.

[pachy-pleuro-whatnot-odon]

I also had another look at the bite mark on your fossil just now. And while there seems to be bit of a wobble and an apparent bifurcation, searching Google for "shark bite mark" immediately resulted in the below image (figure 3 from Cortés et al., 2019), showing grooves very similar to the ones seen on your bone - including aforementioned wobble (see sub 1) and bifurcation (see subs 1 & 2).

 

 

So in retrospect I think it's a quite open and shut case for these being shark bite marks. I've tried to map the ones I could see in the image below, with those gashes, in my opinion, being too deep to be explained away as surface bone texture: