Ptychodus and....marine reptile? (Eagle Ford fm. central texas)

[Jared C]

I finally broke through today, and made some of my proudest finds ever... multiple times.

I have some questions on a few ID's. When I compared these Ptychodus to the Ptychodus ID guide, they kind of reminded me of anonymus and mammilaris. I'm excited because everywhere else I've only ever found mortoni before. I did not find any mortoni here.

 

In the same slab as a ptychodus, there's also a small tooth that's perhaps suggestive of Mosasaur - however, fish teeth from those like pachyrhizodus look deceptively mosasaurian to my inexperienced eye. Furthermore, it's small size could also indicate fish, but a mosasaur pterygoid tooth could be in the running this way still as well. One half is covered in matrix still, so I understand this complicates getting an ID

 

Eagle Ford fm. Travis county, Texas

 

Scale bar = 1 inch 

1.)

 

2.) Ptychodus on the same slab

 

3.) Another Ptychodus (different slab)

 

4.) Fish tooth? Or chance of reptile? (scale bar= 1 inch)

 

 

Edited September 13, 2021 by Jared C
fixing a confusing detail

[LSCHNELLE]

Very nice Jared C!

 

Can you do like Dan (Uncle Siphuncle) did and wash them up and cut around the teeth in matrix just a bit?  That will help with the ID.

 

You don't need to remove them from the matrix.  I personally like them left in when possible.

 

At this point, I see possibilities for mosasaur teeth, but shape is important and much is buried in matrix. I am better at Ptychodus ID.  I see two moderate to high crowned Ptychodus teeth. Depending on how the ridges meet the marginal area, there are several species possibilities. 

 

If you can verify whether you are in Eagle Ford or Austin Atco, that would help.  Also, if in Eagle Ford, are you in the Upper South Bosque Shale or in the Middle Flaggy Member?

 

Thanks. 

Edited September 13, 2021 by LSCHNELLE

[Jared C]

2 minutes ago, LSCHNELLE said:

Very nice Jared C!

 

Can you do like Dan Uncle Siphuncle) did and wash them up and cut around the teeth in matrix just a bit?  That will help with the ID.

 

You don't need to remove them from the matrix.  I personally like them left in when possible.

 

At this point, I see possibilities for mosasaur teeth, but shape is important and much is buried in matrix. I am better at Ptychodus ID.  I see two moderate to high crowned Ptychodus teeth. Depending on how the ridges meet the marginal area, there are several species possibilities. 

 

If you can verify whether you are in Eagle Ford or Austin Atco, that would help.  Also, if in Eagle Ford, are you in the Upper South Bosque Shale or in the Middle Flaggy Member?

 

Thanks. 

Sure thing, I'll do what I can!

I'm a little worried about trying to prepare these, as that's something I've never done before. Should I leave some of these slabs in a vinegar bath to dissolve away the matrix, and then pick at details with a needle? 

 

I'm fairly certain I'm in the Eagle Ford, but I'm unsure of how to tell which member I'm in. What are some features of them? If that's too hard to lay out, I can also just PM you where I found these, if it helps.

[Uncle Siphuncle]

No vinegar.  Start with a wet toothbrush and perhaps a utility blade to scrape away weaker matrix.

[LSCHNELLE]

My guess is that you are in the South Bosque near the top.  These Ptychodus are likely P. anonymous (bottom) and  a new species to be named next year (like P. mortoni, but not quite).  I also suspect that at least one or both teeth are mosasaurs.  But, pliosaur is not out of the question for the second one. 

Do like what Uncle Siphuncle said for prep. See below to see what I like to do. No need to PM location. I don't need to know where you found them.  It looks like Eagle Ford shell hash.  If the hash layer was mainly surrounded by gray/black/tan shale above and below, then you are in South Bosque. If there are thin interlayers of limestone and bentonite/shale for 5 to 15 feet thick above it, then you are in the basal Flaggy Member. 

 

Prep usually can be done with gentle water (no vinegar needed) or soft wet bristle brush (or toothbrush) and an ice pick tool (only if necessary).  But, be careful as the shell hash layer might fall apart if it gets too wet for too long.  When using the ice pick, start from well away from each tooth and work inward parallel to the tooth to avoid damage. Gently pry nearest the tooth to lift loose matrix without touching the fossil with the tool. 

 

If it's too hard for such tools, then you might need an air scribe tool and a blasting cabinet. 

[Jared C]

1 hour ago, LSCHNELLE said:

My guess is that you are in the South Bosque near the top.  These Ptychodus are likely P. anonymous (bottom) and  a new species to be named next year (like P. mortoni, but not quite).  I also suspect that at least one or both teeth are mosasaurs.  But, pliosaur is not out of the question for the second one. 

Do like what Uncle Siphuncle said for prep. See below to see what I like to do. No need to PM location. I don't need to know where you found them.  It looks like Eagle Ford shell hash.  If the hash layer was mainly surrounded by gray/black/tan shale above and below, then you are in South Bosque. If there are thin interlayers of limestone and bentonite/shale for 5 to 15 feet thick above it, then you are in the basal Flaggy Member. 

 

Prep usually can be done with gentle water (no vinegar needed) or soft wet bristle brush (or toothbrush) and an ice pick tool (only if necessary).  But, be careful as the shell hash layer might fall apart if it gets too wet for too long.  When using the ice pick, start from well away from each tooth and work inward parallel to the tooth to avoid damage. Gently pry nearest the tooth to lift loose matrix without touching the fossil with the tool. 

 

If it's too hard for such tools, then you might need an air scribe tool and a blasting cabinet. 

Perfect answer, thank you. Based on your description, I agree with you that I was in South Bosque near the top. Dark shale was above and below the thin hash layer, but the shale above the hash and below the limestone was only a few feet thick.

 

I will begin prep later today, after school and work. Thanks for all the helpful advice!

[LSCHNELLE]

The first Ptychodus tooth looks pretty worn on top.  It may also be a P. anonymous.  If so, then you may be in the Lower Bouldin Flags (Flaggy) Member rather than the Upper South Bosque.  I've seen some with the coarse oyster shell hash layer(s). The way you would know is generally shale below and several thin limestone/shale/bentonite layers above for 5' to 15' overall thickness. 

[siteseer]

When you don't have access or experience with an air abrasive unit or an air scribe, try using a pin vise, which is basically a sturdy, fine-pointed needle set in a holder.  Preparators make their own by setting a good needle in 2-part putty that's been mixed and then molded to a comfortable shape to hold and press with.  It's the idea of being able to apply a good amount of force to a pinpoint of area.  You'd be surprise how effective it can be.  Patience is of course of great importance and you always need to poke away from your body parts.  You don't want to stab yourself.  Wear gloves and safety glasses to protect from chips that can fly everywhere.

 

Did you read the part where I said to wear safety glasses?

Edited September 14, 2021 by siteseer

[LSCHNELLE]

Jared C - just wanted to add that Ptychodus whipplei is also possible for the first higher-crowned tooth in this post. 

[Jared C]

2 hours ago, LSCHNELLE said:

Jared C - just wanted to add that Ptychodus whipplei is also possible for the first higher-crowned tooth in this post. 

Cool, I'm still prepping here and there where I have time, so I'll be uploading everything at once again for an ID once complete - then we could be sure

[Jared C]

Ok, I've done some prep, so these should be easier to identify. Just a reminder, these are from the Eagle Ford of Travis county. The big slab will not be prepped further until I can get my hands on some glues and crack fillers.

 

1.) Little prep done, mostly cleaned as compared to before. Based on the pinned ptychodus ID quick guide, I'm strongly leaning towards P. occidentalis. My main reasoning is the curved crown angle to the margin. Confirm or deny?

 

2.) This ptychodus i'm less sure of - the little bit of feeding damage complicates things. Perhaps whipplei? I know that's supposed to be uncommon around here though, so it's a stretch. This is the tooth I found right before that crazy slab. This is the one that just had the tiny tip bit poking out. ID?

 

3.) This little Ptychodus is odd - it's quite small so it may come from a juvenile, so perhaps the tooth isn't fully formed yet. Also not at a convenient angle for ID. Any thoughts?

 

4.) This is what I thought might be a fish tooth - prepping has made me 85% sure it's mosasaur now. I think I see a cutting ridge. Unfortunately the rotting pyrite on top of it took a bit of enamel off.Also,  I must say, if it's mosasaur than it's very small, probably less than 2 cm in length. ID?

 

 

[LSCHNELLE]

Jared C. Thanks for the nice prep.  Sorry that you lost some of the fourth tooth enamel in the process.

 

I am very certain now that you are in Middle to Upper South Bosque. My first impression appears to be what I am leaning toward. The second and third teeth are the new species that Shawn Hamm should be referencing soon in a paper.  Therefore, the first tooth cannot be P. occidentalis as you think. It is gone around the late Cenomanian.  This is Turonian age rock. It is either P. anonymous (lateral file) where slight curvature (but not u-turn) is possible at the base of some ridges; or, it is a P. mammillaris lateral (due to offset and wide crown).  I think that the key differences between P. occidentalis and the latter two species would be finer ridges and a dendritic pattern outward toward the edge of the tooth.

 

I am not sure whether your tooth is a mosasaur/russellosaurus or a plesiosaur/pliosaur.  Maybe, @pachy-pleuro-whatnot-odon can chime in. 

[RuMert]

Looks like the reptile tooth has carinae, so shouldn't be a plesiosaur

[Jared C]

1 hour ago, LSCHNELLE said:

Jared C. Thanks for the nice prep.  Sorry that you lost some of the fourth tooth enamel in the process.

 

I am very certain now that you are in Middle to Upper South Bosque. My first impression appears to be what I am leaning toward. The second and third teeth are the new species that Shawn Hamm should be referencing soon in a paper.  Therefore, the first tooth cannot be P. occidentalis as you think. It is gone around the late Cenomanian.  This is Turonian age rock. It is either P. anonymous (lateral file) where slight curvature (but not u-turn) is possible at the base of some ridges; or, it is a P. mammillaris lateral (due to offset and wide crown).  I think that the key differences between P. occidentalis and the latter two species would be finer ridges and a dendritic pattern outward toward the edge of the tooth.

 

I am not sure whether your tooth is a mosasaur/russellosaurus or a plesiosaur/pliosaur.  Maybe, @pachy-pleuro-whatnot-odon can chime in. 

Lots of great info here, thanks! As for the teeth that are soon to be described... are they a common tooth formerly considered to be mortoni, and are now being reclassified because Hamm has decided that it's differences are important enough? Or is it only being described soon because it's a tooth that's been discovered recently? What's the distinguishing feature of this tooth that tipped you off?

 

Also, regarding the first tooth, thanks for that info - especially on the specific age. based on what you said, after looking at it again, I'm leaning a bit towards P. anonymous, as reading the rest of the Ptuchodus ID thread suggested that I can expect a mammilaris crown to be a slightly more squared. I know my pictures didn't show that shape well, so my apologies. 

As usual, thanks for being so wonderfully helpful

[LSCHNELLE]

Your welcome.  Again, I have strong opinions - not necessarily correct - without a full set of teeth like @Ramo believes is best.  I respect his opinion. So, many people won't try to ID species because of heterogeneity in associated tooth sets. I base it on a combination of tooth ridges, marginal features, crown height, and tooth shape plus stratigraphic hints.  I think that Shawn Hamm also believes in incorporating stratigraphy into his educated guesses.

 

I understand that the tooth that is the pending new species has been known for decades.  No scientist has tried to distinguish it from P. anonymous (which is concurrent with it at the end of the Turonian) and P. mortoni (to which it has great affinity and which is not known until the Coniacian). 

[pachy-pleuro-whatnot-odon]

Wow! Nice haul, Jared! Definitely your lucky day, I'd say!

 

7 hours ago, LSCHNELLE said:

I am not sure whether your tooth is a mosasaur/russellosaurus or a plesiosaur/pliosaur.  Maybe, @pachy-pleuro-whatnot-odon can chime in.

 

I believe that the two teeth that are not Ptychodus are indeed reptile teeth, almost certainly mosasaurid. As @RuMert correctly already pointed out, the teeth can't be plesiosaurian as they've got carinae, and plesiosaurs don't have carinae; and while they may have apicobasal ridges, those run from bottom to top, rather than from top to bottom, as do carinae.

 

I'd say that the first specimen looks rather like a plioplatecarpine tooth, so it may be something affiliated to Ectenosaurus clidastoides as figured below from Oceans of Kansas (inventory FHSM VP-401), although the ornamentation pattern seems a lot more course in your piece. However, with E. clidastoides being a lot younger, the teeth may have evolved to become more refined over time...

 

 

 

The other tooth to me rather looks like a russelosaurine, much like the ones Lee himself found in the same formation:

 

On 8/7/2021 at 7:24 AM, LSCHNELLE said:

 

As to prepping techniques, there are various that work for soft shale to various extents. Now I'm not familiar with the types of sediment that occur at the Eagle Ford Fm. and South Bosque, but from what I get it sounds pretty similar to various matrix types I've been working with.

 

On 9/13/2021 at 2:21 PM, LSCHNELLE said:

Prep usually can be done with gentle water (no vinegar needed) or soft wet bristle brush (or toothbrush) and an ice pick tool (only if necessary).  But, be careful as the shell hash layer might fall apart if it gets too wet for too long.  When using the ice pick, start from well away from each tooth and work inward parallel to the tooth to avoid damage. Gently pry nearest the tooth to lift loose matrix without touching the fossil with the tool.

 

Water can be indeed be a very good tool to soften the matrix, especially if it's of a sandy type. With a clay matrix it's less ideal, however, as the clay will take longer to suck the water up, and if you start brushing the clay, you're more likely to create a muddy mess than to actually clean things up. I therefore almost exclusively work with various kinds of pick. Indeed start working far away from the tooth and excavate around it. Depending on the size of the tooth, you can always remove any adhering matrix from it later, when holding it loose in your hand. However, for smaller specimens, it might be best to already narrow down on the tooth while it's still somewhat attached to the matrix, since at least you'll have a natural "clamp" to hold it while you work. I tend to work from tip to base (evenly for the most part, but just emphasising extraction of the tip first), as this allows the biggest part of the tooth to remain attached in the matrix for support of your prep-work. Notwithstanding this focus, however, it's important to work your way around the tooth evenly to ensure that you don't create a point where the resistance of the matrix is greater than in the area you're working on, as this risks breaking the tooth...

 

On 9/14/2021 at 8:04 AM, siteseer said:

When you don't have access or experience with an air abrasive unit or an air scribe, try using a pin vise, which is basically a sturdy, fine-pointed needle set in a holder.  Preparators make their own by setting a good needle in 2-part putty that's been mixed and then molded to a comfortable shape to hold and press with.  It's the idea of being able to apply a good amount of force to a pinpoint of area.  You'd be surprise how effective it can be.  Patience is of course of great importance and you always need to poke away from your body parts.  You don't want to stab yourself.  Wear gloves and safety glasses to protect from chips that can fly everywhere.

 

While you can undoubtedly create your own pin vises, an easier way to start with tools of known quality might be to get a set of dental picks. These tools are ideal to carefully scratch away patches of loose matrix, while simultaneously giving you sufficient control to work close to your specimen as well... Dissection needles are also very useful in this regard, though serve a slightly different purpose. As they are somewhat flexible, they can be used to superficially scratch or poke away loose sandy matrix, where the flexibility of the needle acts as a kind of spring-mechanism. Always remove only small amount of rock at a time when working close to the specimen, to reduce the risk of stresses in the rock breaking it. Whereas you should indeed always work with the sharp end of the tool pointing away from you, when removing the last bits of matrix clinging close to the specimen, I find it works best to direct the point to the fossil, so that you can press the matrix off. In order to reduce risk to the tooth, and if the matrix allows it, I prefer to use sturdy wooden tooth picks at this point. On valuable or fragile specimens you can cover each newly exposed piece of fossil with a thin layer of Paraloid or Vinac to consolidate it and ensure it doesn't get damaged during further work (treatment with either substance is generally recommended with teeth from this location, as it is possible for them to break).

 

All this having been said, though, everyone needs to find their own way of doing things. And I think you already did a marvellous job on the prep. Don't worry too much about the enamel having been lost because of the pyrite. Sure, it's a pity, but 1) it happens to everyone, and 2) it's better to be rid of the pyrite than to have it cling around...

 

On 9/14/2021 at 8:04 AM, siteseer said:

Did you read the part where I said to wear safety glasses?

 

While safety glasses are a nuisance - mine always fog up, irrespective of the type I use - this is a warning to heed. You might hardly ever need them, but especially when you start popping off bits of matrix, it only takes a single unlucky chip to reach your eye...

[Jared C]

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

Wow! Nice haul, Jared! Definitely your lucky day, I'd say!

 

 

I believe that the two teeth that are not Ptychodus are indeed reptile teeth, almost certainly mosasaurid. As @RuMert correctly already pointed out, the teeth can't be plesiosaurian as they've got carinae, and plesiosaurs don't have carinae; and while they may have apicobasal ridges, those run from bottom to top, rather than from top to bottom, as do carinae.

 

I'd say that the first specimen looks rather like a plioplatecarpine tooth, so it may be something affiliated to Ectenosaurus clidastoides as figured below from Oceans of Kansas (inventory FHSM VP-401), although the ornamentation pattern seems a lot more course in your piece. However, with E. clidastoides being a lot younger, the teeth may have evolved to become more refined over time...

 

 

 

The other tooth to me rather looks like a russelosaurine, much like the ones Lee himself found in the same formation:

 

 

As to prepping techniques, there are various that work for soft shale to various extents. Now I'm not familiar with the types of sediment that occur at the Eagle Ford Fm. and South Bosque, but from what I get it sounds pretty similar to various matrix types I've been working with.

 

 

Water can be indeed be a very good tool to soften the matrix, especially if it's of a sandy type. With a clay matrix it's less ideal, however, as the clay will take longer to suck the water up, and if you start brushing the clay, you're more likely to create a muddy mess than to actually clean things up. I therefore almost exclusively work with various kinds of pick. Indeed start working far away from the tooth and excavate around it. Depending on the size of the tooth, you can always remove any adhering matrix from it later, when holding it loose in your hand. However, for smaller specimens, it might be best to already narrow down on the tooth while it's still somewhat attached to the matrix, since at least you'll have a natural "clamp" to hold it while you work. I tend to work from tip to base (evenly for the most part, but just emphasising extraction of the tip first), as this allows the biggest part of the tooth to remain attached in the matrix for support of your prep-work. Notwithstanding this focus, however, it's important to work your way around the tooth evenly to ensure that you don't create a point where the resistance of the matrix is greater than in the area you're working on, as this risks breaking the tooth...

 

 

While you can undoubtedly create your own pin vises, an easier way to start with tools of known quality might be to get a set of dental picks. These tools are ideal to carefully scratch away patches of loose matrix, while simultaneously giving you sufficient control to work close to your specimen as well... Dissection needles are also very useful in this regard, though serve a slightly different purpose. As they are somewhat flexible, they can be used to superficially scratch or poke away loose sandy matrix, where the flexibility of the needle acts as a kind of spring-mechanism. Always remove only small amount of rock at a time when working close to the specimen, to reduce the risk of stresses in the rock breaking it. Whereas you should indeed always work with the sharp end of the tool pointing away from you, when removing the last bits of matrix clinging close to the specimen, I find it works best to direct the point to the fossil, so that you can press the matrix off. In order to reduce risk to the tooth, and if the matrix allows it, I prefer to use sturdy wooden tooth picks at this point. On valuable or fragile specimens you can cover each newly exposed piece of fossil with a thin layer of Paraloid or Vinac to consolidate it and ensure it doesn't get damaged during further work (treatment with either substance is generally recommended with teeth from this location, as it is possible for them to break).

 

All this having been said, though, everyone needs to find their own way of doing things. And I think you already did a marvellous job on the prep. Don't worry too much about the enamel having been lost because of the pyrite. Sure, it's a pity, but 1) it happens to everyone, and 2) it's better to be rid of the pyrite than to have it cling around...

 

 

While safety glasses are a nuisance - mine always fog up, irrespective of the type I use - this is a warning to heed. You might hardly ever need them, but especially when you start popping off bits of matrix, it only takes a single unlucky chip to reach your eye...

Thank you for the fantastic answer - I will undoubtedly return to this post, as it's a treasure trove of information.

I just looked at the Wikipedia article for the Plioplaticarpinae, and it seems that they're a sub family under Russellosaurina - perhaps I'm a little confused about the distinction made about the second tooth there. What am I missing?

[siteseer]

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

Wow! Nice haul, Jared! Definitely your lucky day, I'd say!

 

 

I believe that the two teeth that are not Ptychodus are indeed reptile teeth, almost certainly mosasaurid. As @RuMert correctly already pointed out, the teeth can't be plesiosaurian as they've got carinae, and plesiosaurs don't have carinae; and while they may have apicobasal ridges, those run from bottom to top, rather than from top to bottom, as do carinae.

 

I'd say that the first specimen looks rather like a plioplatecarpine tooth, so it may be something affiliated to Ectenosaurus clidastoides as figured below from Oceans of Kansas (inventory FHSM VP-401), although the ornamentation pattern seems a lot more course in your piece. However, with E. clidastoides being a lot younger, the teeth may have evolved to become more refined over time...

 

 

 

The other tooth to me rather looks like a russelosaurine, much like the ones Lee himself found in the same formation:

 

 

As to prepping techniques, there are various that work for soft shale to various extents. Now I'm not familiar with the types of sediment that occur at the Eagle Ford Fm. and South Bosque, but from what I get it sounds pretty similar to various matrix types I've been working with.

 

 

Water can be indeed be a very good tool to soften the matrix, especially if it's of a sandy type. With a clay matrix it's less ideal, however, as the clay will take longer to suck the water up, and if you start brushing the clay, you're more likely to create a muddy mess than to actually clean things up. I therefore almost exclusively work with various kinds of pick. Indeed start working far away from the tooth and excavate around it. Depending on the size of the tooth, you can always remove any adhering matrix from it later, when holding it loose in your hand. However, for smaller specimens, it might be best to already narrow down on the tooth while it's still somewhat attached to the matrix, since at least you'll have a natural "clamp" to hold it while you work. I tend to work from tip to base (evenly for the most part, but just emphasising extraction of the tip first), as this allows the biggest part of the tooth to remain attached in the matrix for support of your prep-work. Notwithstanding this focus, however, it's important to work your way around the tooth evenly to ensure that you don't create a point where the resistance of the matrix is greater than in the area you're working on, as this risks breaking the tooth...

 

 

While you can undoubtedly create your own pin vises, an easier way to start with tools of known quality might be to get a set of dental picks. These tools are ideal to carefully scratch away patches of loose matrix, while simultaneously giving you sufficient control to work close to your specimen as well... Dissection needles are also very useful in this regard, though serve a slightly different purpose. As they are somewhat flexible, they can be used to superficially scratch or poke away loose sandy matrix, where the flexibility of the needle acts as a kind of spring-mechanism. Always remove only small amount of rock at a time when working close to the specimen, to reduce the risk of stresses in the rock breaking it. Whereas you should indeed always work with the sharp end of the tool pointing away from you, when removing the last bits of matrix clinging close to the specimen, I find it works best to direct the point to the fossil, so that you can press the matrix off. In order to reduce risk to the tooth, and if the matrix allows it, I prefer to use sturdy wooden tooth picks at this point. On valuable or fragile specimens you can cover each newly exposed piece of fossil with a thin layer of Paraloid or Vinac to consolidate it and ensure it doesn't get damaged during further work (treatment with either substance is generally recommended with teeth from this location, as it is possible for them to break).

 

All this having been said, though, everyone needs to find their own way of doing things. And I think you already did a marvellous job on the prep. Don't worry too much about the enamel having been lost because of the pyrite. Sure, it's a pity, but 1) it happens to everyone, and 2) it's better to be rid of the pyrite than to have it cling around...

 

 

While safety glasses are a nuisance - mine always fog up, irrespective of the type I use - this is a warning to heed. You might hardly ever need them, but especially when you start popping off bits of matrix, it only takes a single unlucky chip to reach your eye...

 

I've never used dissection needles and will have to try that.  I have used a scalpel with various blades and they are very effective on soft to moderately hard matrix.

 

I always wear safety glasses when I prep.  I put them on before I sit down.  There have been two times when I was pressing with a scalpel and the tip of the blade snapped off and bounced off a lens of my safety glasses.

 

 

[pachy-pleuro-whatnot-odon]

2 hours ago, siteseer said:

I've never used dissection needles and will have to try that.  I have used a scalpel with various blades and they are very effective on soft to moderately hard matrix.

 

I got one with the toy microscope I had as a teenager. I kept it, and it turned out to be very effective for certain types of prep. I mainly use it when prepping Moroccan stuff, as it easily removed the matrix, is a bit sturdier and wooden tooth picks, but at the same time less dangerous to the fossil than a dental pick I've also seen them around other preparation labs, so that told me my experiences are not mine alone

 

2 hours ago, siteseer said:

I always wear safety glasses when I prep.  I put them on before I sit down.  There have been two times when I was pressing with a scalpel and the tip of the blade snapped off and bounced off a lens of my safety glasses.

 

Wow! That sounds pretty dangerous! Even if it wouldn't have hit the lens but your face, that would still have been very nasty!

For a long time I didn't use to wear safety glasses as they fog up so quickly. However, I've become more careful after a tiny stone chip jumped into my eye. Again, rather nasty, but luckily in my case it didn't have any lasting consequences. Still, I'm a lot more weary of using proper safety precautions now

 

5 hours ago, Jared C said:

I just looked at the Wikipedia article for the Plioplaticarpinae, and it seems that they're a sub family under Russellosaurina - perhaps I'm a little confused about the distinction made about the second tooth there. What am I missing?

 

Plioplatecarpinae is just a bit more specific than russelosaurinae, which is a grouping that basically includes all non-halisaurine and non-mosasaurine mosasaurs. In other words, if it's not a hailsaurine and not a true mosasaur, than it's a russelosaur. This includes such diverse subgroups as tethysaurines and tylosaurines. Me stating the one tooth is plioplatecarpine and the russelosaurine just means that I feel the one tooth can be classified with more precision than the other - but I agree that my wording does come across as a bit confusing...