Is this a Mosasaur? Teeth and Jaw Fragment...

[JamieC7696]

Bought in East Anglia, UK, are these teeth and attached fragmentary jaw parts of a mosasaur? Or - something just a little bit different?

 

The whole piece hails (apparently) from Khouribga, Morocco...

[Nanotyrannus35]

Looks to me like the teeth might be composites.

[Praefectus]

Real Prognathodon teeth. It is not an original piece. The teeth have been composited together. 

[JamieC7696]

If indeed it is a composite (looking increasingly likely - if not certain...), please do attempt to tell me what animal the bone fragment comes from?

 

In an artistic sense, its newly found out chimeric quality certainly appeals to me... But I'd like to know the above - for even greater appreciation!

[Praefectus]

It is a random piece of bone from the Moroccan Phosphates. I don't think it is identifiable, but based on what is common, it is likely mosasaurid. Not necessarily jaw bone, though. 

[JamieC7696]

2 hours ago, Praefectus said:

It is a random piece of bone from the Moroccan Phosphates. I don't think it is identifiable, but based on what is common, it is likely mosasaurid. Not necessarily jaw bone, though. 

Altogether, I think you have given a very good overview; thank you so very much!

 

To the educated eye, what, then, makes it conclusively a composite (if that's for certain)? To my own, untrained eye - I personally thought the bone looks younger (on which subject I'm probably wrong...) and something about the teeth... But, then, I have no idea what a matching pair indeed should look like!

 

Last of all, rate it visually - on a scale of one through to ten (one = the fossil equivalent of the Pokemon Dracovish; and ten = of museum display quality, and difficult - if decisively - determinable as a composite). No feelings will be hurt here: I was certainly not the maker of this composite!

Edited March 12, 2022 by JamieC7696

[Nanotyrannus35]

1 hour ago, JamieC7696 said:

To the educated eye, what, then, makes it conclusively a composite (if that's for certain)?

The different colors of the teeth, and sometimes the joint between the two looks oddly uniform in color. @pachy-pleuro-whatnot-odon would know more

[JamieC7696]

I'm just adding a few additional photos - focused upon the overhead view... I'm still very interested in how these may confirm your theories, and - especially - in how this suspected composite may've been put together!

Edited March 13, 2022 by JamieC7696

[pachy-pleuro-whatnot-odon]

On 3/12/2022 at 9:15 PM, JamieC7696 said:

Last of all, rate it visually - on a scale of one through to ten (one = the fossil equivalent of the Pokemon Dracovish; and ten = of museum display quality, and difficult - if decisively - determinable as a composite). No feelings will be hurt here: I was certainly not the maker of this composite!

 

Lets start with the easiest question to answer, as unless a specimen was bought for scientific purposes (in which case, you'd need it to be as authentic and unaltered as possible) or specifically as an investment (in which case resalability is a serious concern), this question doesn't really hold any relevance. For, as when dealing with most objects that are purchased for their artistic merit, their value is ultimately in the eye of the beholder, and thus their price dependent upon that. This is also known as "an object is worth whatever someone is willing to pay for it". And this even goes for museums, as not all of them serve the same basic function, target the same audience or have the same expertise...

 

On 3/12/2022 at 9:15 PM, JamieC7696 said:

To the educated eye, what, then, makes it conclusively a composite (if that's for certain)? To my own, untrained eye - I personally thought the bone looks younger (on which subject I'm probably wrong...) and something about the teeth... But, then, I have no idea what a matching pair indeed should look like!

 

On 3/13/2022 at 12:36 PM, JamieC7696 said:

I'm still very interested in how these may confirm your theories, and - especially - in how this suspected composite may've been put together!

 

As to your second question: this is a lot more difficult to answer, as there are not only a lot of factors at play that need to be taken into consideration, but, above all, the state of the object is actually rather hard to determine since it's so covered up with matrix. However, a first red flag with this piece is that the teeth, located so closely together, have significantly different morphologies: the "ribbing" (faceting) on the one tooth is much more prominent on the one tooth versus the other, for example, as is the dark colour that derives from thickened enamel used to crush tough/hard food items (that is, durophagous adaptions). Sizes and curvatures also don't match up. Thus, while both teeth are certainly prognathodontid and it appears possible that they'd have come from the same species (the situation concerning the genus Prognathodon in Morocco is currently a bit unclear, unfortunately), the differences between the teeth are greater (as a cumulative effect of the features I mentioned before) than what you'd naturally see in mosasaur dentition, even taking their heterodontous nature into account.

 

Another good indication of this piece having been altered is that the vascularization of the bone onto which the teeth have been attached runs in the wrong direction for a piece of jaw-bone. In your specimen you can see the main orientation of the honey-comb structure typical of bone running in a rather top-to-bottom direction, instead of being horizontally aligned. Moreover, the cells are way too big for a mosasaur jaw, in which the vascular canals are both much smaller and more compact (osteosclerotic). Compare to the photograph of a mosasaur jaw below.

 

On 3/12/2022 at 4:51 PM, JamieC7696 said:

 

 

And while a lot of random pieces of mosasaur bone are indeed found in the older layers of the phosphate beds, it's also true that in the younger layers, deriving from a time when mosasaurs had gone extinct, such random bone material would rather be attributable to crocodilians. Yet, at the same time, there were plenty of large-bodied fish around during both intervals, which would be a third candidate for the bone that composes the so-called jaw. While it's hard to identify bone from a section so fragmentary and obscured, I do believe the latter - i.e., fish - is the most likely culprit here, based, on the one hand on the large vascular canals present (which, coming from the phosphates, I've mostly seen in fish) and the fact that the only marine reptile bones from the phosphates I've seen in cross-section are much denser/more osteosclerotic, if you can even make out vascularization at all.
 

Which brings me to the preservational aspect of the bone, for it's my understanding that a lot of the bone material - certainly the larger piece of more uniform consistency - is preserved through replacement by gypsum (but see here for potential alternative mineral compounds). This generally leads to a rather uniform consistency of the fossils preserved, which moreover attain the white colour we all know from childhood. Let this colour, consistency and strength, however, be a perfect match for plaster (and wall-filler, by the way), and you can imagine how easy it'd be to fabricate parts of a fossil without much being possible by way of detection or differentiation. Local fossil preparators and dealers in Morocco know this, and thus often embellish the fossils they sell to fetch a higher price. As it'd take too much time to carefully finish most products they sell, though, careful inspection can often point out where changes have been made.

 

In this case, you can tell that at least the lighter-coloured tooth was added (if not the both) due to the shape and colour of the root of this tooth. Whereas a real root would have a neck that gently widens out to a point where it root bends back in on itself before running further down, the root underneath the lighter-coloured tooth doesn't follow this shape. It, moreover, also doesn't exhibit the typical fibrous texture you'd expect to see on a root and, on close inspection, you can even make out how the plaster from which the root was most likely constructed sits on top of the bone underneath. And while I don't have sufficiently qualitative photographs available to make out whether the same is the case for the darker-coloured tooth, the one photograph that does show the connection well suggests that it is - which would make sense seeing as the underlying bone doesn't go together with either of the teeth.

 

On 3/13/2022 at 12:36 PM, JamieC7696 said:

 

As such, this piece is unfortunately quite a mess. But it's a good educational specimen, and so I hope the above information is helpful in learning how to make out the types of modifications Moroccan dealers will make to make specimens more alluring...

[Mark Kmiecik]

If you'd like to know how they are composited, take some Elmer's Glue and mix it with some sand and then shape it as you wish and stick something into it. That's basically how it's done but they use waterproof glues in most cases and sediment finer than sand for the base material and add coarser sediment onto the surface so only one side has glue on it to hide the glue.

[pachy-pleuro-whatnot-odon]

Yeah, the fossils in the phosphates are indeed found in marls of different grain size and different hardness/consistency. A lot of diluted white glue (wood glue) is often poured out over the fossils so as to consolidate them and the matrix they're in. While the glue does seep into the matrix somewhat, it doesn't really penetrate the bone too well due the high density of the bone's replacement material. As such, the glue ends up forming a thin film across the bones which can easily be removed with a scalpel or preparators' needle, but also using acetone. However, as most of these glues are water-soluble, it's often enough to put a piece like this in water to dissolve the matrix around the fossils. Be careful if you ever intend to do this, however, as this process will also undo many repairs and elaborations, while also making the fossils themselves more fragile (both for sake of their supporting matrix being removed as well as for soaking up moisture).

 

The net result of this combination of natural preservation and the way this is consolidated, however, is that you indeed end up with a bit of a sculpture, shapes of sand and gypsum frozen by the use of copious (often excessive) amounts of glue. This being the case, it's easy to see how you could sculpt additions and elaborations that can be hard to differentiate from the original specimen

[JamieC7696]

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

 

Lets start with the easiest question to answer, as unless a specimen was bought for scientific purposes (in which case, you'd need it to be as authentic and unaltered as possible) or specifically as an investment (in which case resalability is a serious concern), this question doesn't really hold any relevance. For, as when dealing with most objects that are purchased for their artistic merit, their value is ultimately in the eye of the beholder, and thus their price dependent upon that. This is also known as "an object is worth whatever someone is willing to pay for it". And this even goes for museums, as not all of them serve the same basic function, target the same audience or have the same expertise...

 

 

 

As to your second question: this is a lot more difficult to answer, as there are not only a lot of factors at play that need to be taken into consideration, but, above all, the state of the object is actually rather hard to determine since it's so covered up with matrix. However, a first red flag with this piece is that the teeth, located so closely together, have significantly different morphologies: the "ribbing" (faceting) on the one tooth is much more prominent on the one tooth versus the other, for example, as is the dark colour that derives from thickened enamel used to crush tough/hard food items (that is, durophagous adaptions). Sizes and curvatures also don't match up. Thus, while both teeth are certainly prognathodontid and it appears possible that they'd have come from the same species (the situation concerning the genus Prognathodon in Morocco is currently a bit unclear, unfortunately), the differences between the teeth are greater (as a cumulative effect of the features I mentioned before) than what you'd naturally see in mosasaur dentition, even taking their heterodontous nature into account.

 

Another good indication of this piece having been altered is that the vascularization of the bone onto which the teeth have been attached runs in the wrong direction for a piece of jaw-bone. In your specimen you can see the main orientation of the honey-comb structure typical of bone running in a rather top-to-bottom direction, instead of being horizontally aligned. Moreover, the cells are way too big for a mosasaur jaw, in which the vascular canals are both much smaller and more compact (osteosclerotic). Compare to the photograph of a mosasaur jaw below.

 

 

 

And while a lot of random pieces of mosasaur bone are indeed found in the older layers of the phosphate beds, it's also true that in the younger layers, deriving from a time when mosasaurs had gone extinct, such random bone material would rather be attributable to crocodilians. Yet, at the same time, there were plenty of large-bodied fish around during both intervals, which would be a third candidate for the bone that composes the so-called jaw. While it's hard to identify bone from a section so fragmentary and obscured, I do believe the latter - i.e., fish - is the most likely culprit here, based, on the one hand on the large vascular canals present (which, coming from the phosphates, I've mostly seen in fish) and the fact that the only marine reptile bones from the phosphates I've seen in cross-section are much denser/more osteosclerotic, if you can even make out vascularization at all.
 

Which brings me to the preservational aspect of the bone, for it's my understanding that a lot of the bone material - certainly the larger piece of more uniform consistency - is preserved through replacement by gypsum (but see here for potential alternative mineral compounds). This generally leads to a rather uniform consistency of the fossils preserved, which moreover attain the white colour we all know from childhood. Let this colour, consistency and strength, however, be a perfect match for plaster (and wall-filler, by the way), and you can imagine how easy it'd be to fabricate parts of a fossil without much being possible by way of detection or differentiation. Local fossil preparators and dealers in Morocco know this, and thus often embellish the fossils they sell to fetch a higher price. As it'd take too much time to carefully finish most products they sell, though, careful inspection can often point out where changes have been made.

 

In this case, you can tell that at least the lighter-coloured tooth was added (if not the both) due to the shape and colour of the root of this tooth. Whereas a real root would have a neck that gently widens out to a point where it root bends back in on itself before running further down, the root underneath the lighter-coloured tooth doesn't follow this shape. It, moreover, also doesn't exhibit the typical fibrous texture you'd expect to see on a root and, on close inspection, you can even make out how the plaster from which the root was most likely constructed sits on top of the bone underneath. And while I don't have sufficiently qualitative photographs available to make out whether the same is the case for the darker-coloured tooth, the one photograph that does show the connection well suggests that it is - which would make sense seeing as the underlying bone doesn't go together with either of the teeth.

 

 

As such, this piece is unfortunately quite a mess. But it's a good educational specimen, and so I hope the above information is helpful in learning how to make out the types of modifications Moroccan dealers will make to make specimens more alluring...

Wow - thank you, for your time and attention on defining this composite: I can totally see that now, through educated eyes... Such a process really would make for a great analogy: for how being extensively informed may completely transform the limits of what one can possibly see.

 

Previously - myself coming from an academic background - I mostly trusted the consensus on here of those obviously much better informed than me; but, only being human, it's surprising how - without the 'how', and more just the 'symptoms' being accounted for - the mind finds ways to wonder, see, and justify what it wants to see: 'What if it really needs to be physically examined - it feels so 'whole' to me?', etc.

 

Nevertheless - as a chimeric art piece - I'm glad to own the surviving remains of two Mosasaurs, and that (most probably) of some undeterminable, prehistoric fish!

[pachy-pleuro-whatnot-odon]

15 minutes ago, JamieC7696 said:

the mind finds ways to wonder, see, and justify what it wants to see

 

This is definitely very true in the search for and collection of fossils: the mind sees what it wants to see, to the extent that even academics and experienced collectors can fall victim of these biases But I'm glad you'll now look at Moroccan specimens with more educated eyes - your first steps in a hugely pedagogical experience!

[JamieC7696]

On 3/15/2022 at 2:15 PM, pachy-pleuro-whatnot-odon said:

 

This is definitely very true in the search for and collection of fossils: the mind sees what it wants to see, to the extent that even academics and experienced collectors can fall victim of these biases But I'm glad you'll now look at Moroccan specimens with more educated eyes - your first steps in a hugely pedagogical experience!

 

On 3/12/2022 at 5:20 PM, Praefectus said:

It is a random piece of bone from the Moroccan Phosphates. I don't think it is identifiable, but based on what is common, it is likely mosasaurid. Not necessarily jaw bone, though. 

 

On 3/12/2022 at 9:38 PM, Nanotyrannus35 said:

The different colors of the teeth, and sometimes the joint between the two looks oddly uniform in color. @pachy-pleuro-whatnot-odon would know more

 

On 3/15/2022 at 1:51 AM, Mark Kmiecik said:

If you'd like to know how they are composited, take some Elmer's Glue and mix it with some sand and then shape it as you wish and stick something into it. That's basically how it's done but they use waterproof glues in most cases and sediment finer than sand for the base material and add coarser sediment onto the surface so only one side has glue on it to hide the glue.

I thought the following would provide a great conclusion to what has turned out to be an educational piece: a mosasaur tooth - which, I suspect, hasn't been fiddled with (if, indeed, I've not learned little...)!

 

Helpful, I think, is that its origins are exactly the same as the investigated 'jaw'.

[pachy-pleuro-whatnot-odon]

There's what seems to be a bit of damage to the enamel at the base of the crown on the last photograph, and that same photograph shows a somewhat thicker edge to the tooth than I'd have expected to see (thus possibly hinting at a slight pathology), but otherwise this looks like a fine and unaltered prognathodontid tooth, albeit with a fair bit of matrix still clinging to the base of the tooth. Nice!