STH Micro Matrix

[Meganeura]

So I was recently lucky enough to very generously receive some amazing and very very rich STH micro matrix! So here’s the finds, ID help courtesy of @digit and @MarcoSr’s website.

 

Starting off with the shark teeth - alongside the micro mix I was given a very nice C. planus tooth. So here’s that alongside the 2 C. hastalis teeth I found:

 

Bigger other shark teeth - Negaprion, Carcharhinus:

 

Squatina - Angel Shark:

 

Squalus - dog shark:

 

Cretorhinus - Basking Shark:

 

Galeorhinus - Tope Shark:

 

Symphyseal tope shark:

 

Triakis sp. - Hound Shark:

 

 

Heterodontus sp. - Horn Shark:

 

Posterior:

 

Anterior:

 

Dermal denticles:

 

Vertebrae and fish spines:

 

Fish teeth:

 

Pharyngeal fish teeth:

 

Now onto the Ray teeth - Dasyatis and Gymnura cause I can’t tell the difference - there were SO MANY OF THESE! Easily 300+.

The nuptial/male/breeding teeth from Dasyatis and Gymnura:

 

Mustelus sp (Smooth-hound shark) and Rhinobatus sp. (Guitarfish) cause I really can’t tell the difference either:

 

Mobula sp:

 

And finally, the 3 Raja (Skate) teeth I found:

 

There were a couple other finds - couple triggerfish teeth, a barracuda tooth, etc as well! I went through the matrix twice and I know I’ve missed stuff too. Im surprised I didn’t find any shark denticles, but ah well.
 

Also not included is all the Ray mouth plates and broken shark and Ray teeth I found! 

 

Tons of stuff that I’m very happy with! If anyone wants pictures of anything in particular do let me know!

 

Edited May 23, 2023 by Meganeura

[Tidgy's Dad]

Golly!  

Very nice. 

[GeschWhat]

Wow!

[Meganeura]

Just now, GeschWhat said:

Wow!

My thoughts exactly! Unfortunately there was a distinct lack of coprolite (As far as I could tell!)

[LAcrab]

Super cool. I went through half a bucket of this same STH matrix and found lots of small teeth also. I'm a newb and this helped me with the ID on some of mine. I had no idea those little balls were Pharyngeal fish teeth! Threw those out, oops. But here is one of the Heterodontus sp. I believe? That's the tip of a needle. Things are soooo tiny. 

[Meganeura]

1 hour ago, LAcrab said:

Super cool. I went through half a bucket of this same STH matrix and found lots of small teeth also. I'm a newb and this helped me with the ID on some of mine. I had no idea those little balls were Pharyngeal fish teeth! Threw those out, oops. But here is one of the Heterodontus sp. I believe? That's the tip of a needle. Things are soooo tiny. 

I believe this is actually a Mobula sp. tooth - not Heterodontus! Heterodontus teeth don’t have the the double pronged root like Mobula and other Ray/skate teeth have. 

[ClearLake]

Very nice!

[ThePhysicist]

Awesome! Gotta get me some of that stuff 

[GeschWhat]

On 5/23/2023 at 9:56 AM, Meganeura said:

My thoughts exactly! Unfortunately there was a distinct lack of coprolite (As far as I could tell!)

 

I guess you can't have everything...

[Nimravis]

Nice stuff Daniel and as I told you before, the micro matrix fro STH is the best that I ever searched. If you still have the matrix that you went through already, I suggest that you rinse it in a strainer with hot water and research it. I use to do this several times and continued to find stuff that I missed, some pieces were extremely small.

[Meganeura]

8 hours ago, Nimravis said:

Nice stuff Daniel and as I told you before, the micro matrix fro STH is the best that I ever searched. If you still have the matrix that you went through already, I suggest that you rinse it in a strainer with hot water and research it. I use to do this several times and continued to find stuff that I missed, some pieces were extremely small.

I’ll do that! I’ve still got it!

[siteseer]

Hi Meganeura,

 

You would have to photograph individual teeth from lingual, labial views so we can take a look.  Lateral, apical, and basal view would help too.  Dasyatis is found in roughly a 2-4mm size range and can be variable in morphology.  At least one researchers has stated that trying to name teeth to species and even to genus in some cases is a mistake.  There can be a lot of variation in the teeth in the jaws of one individual.

 

Gymnura teeth are generally smaller (1-1.5mm) than the dasyatid teeth in the STH Bonebed.  Unlike the dasyatid teeth, the crown follows a V-like shape with a rather sharp cusp formed from the union of two projections (cusps).  Gymnura teeth are uncommon even when screening.

 

The labial face of the crown of a Mustelus tooth has several vertical ridges (folds) while Rhinobatos has smooth crowns.  Rhinobatos is often a taller tooth (crown and root) than it is wide while Mustelus is generally shorter.  Rhinobatos has a distinct central uvula that extends basally and is flanked by shorter ones.  Mustelus can resemble that but the uvula is shorter and broader and there tends to be more of a cusp on the crown though it is blunt and not always distinct.  The roots of these two genera can be very similar but they are usually not well-preserved so hang onto a few with nice roots so you have reference specimens. 

 

I'm not sure you have shown a Raja tooth yet.  They are uncommon even when you are good with micros.

 

Oh yeah, I would definitely go back through the matrix.  There are teeth less than a millimeter in that.

 

Jess

[Notidanodon]

Great finds your sympaheseal tope shark tooth is very interesting, in my opinion the root structure is more like abdounia though I know that’s not in the fauna  

[Meganeura]

10 hours ago, siteseer said:

Hi Meganeura,

 

You would have to photograph individual teeth from lingual, labial views so we can take a look.  Lateral, apical, and basal view would help too.  Dasyatis is found in roughly a 2-4mm size range and can be variable in morphology.  At least one researchers has stated that trying to name teeth to species and even to genus in some cases is a mistake.  There can be a lot of variation in the teeth in the jaws of one individual.

 

Gymnura teeth are generally smaller (1-1.5mm) than the dasyatid teeth in the STH Bonebed.  Unlike the dasyatid teeth, the crown follows a V-like shaape with a rather sharp cusp formed from the union of two projections (cusps).  Gymnura teeth are uncommon even when screening.

 

The labial face of the crown of a Mustelus tooth has several vertical ridges (folds) while Rhinobatos has smooth crowns.  Rhinobatis is often a taller tooth (crown and root) than it is wide while Mustelus is generally shorter.  Rhinobatos has a distinct central uvula that extends basally and is flanked by shorter ones.  Mustelus can resemble that but the uvula is shorter and broader and there tends to be more of a cusp on the crown though it is blunt and not always distinct.  The roots of these two genera can be very similar but they are usually not well-preserved so hang onto a few with nice roots so you have reference specimens. 

 

I'm not sure you have shown a Raja tooth yet.  They are uncommon even when you are good with micros.

 

Oh yeah, I would definitely go back through the matrix.  There are teeth less than a millimeter in that.

 

Jess

Thanks Jess! @digit confirmed that one of my teeth at the very least was in fact Raja - it had very wide roots. Apologies for the poor picture:

 

 

As far as the Mustelus vs Rhinobatus - I’ve definitely got a few with the good root structure still so I’m glad to have those as reference teeth!

 

Much appreciated on the info though. I’ll have to see if I can find any Gymnura teeth. And of course, keep looking for even smaller teeth!

[Meganeura]

3 hours ago, Notidanodon said:

Great finds your sympaheseal tope shark tooth is very interesting, in my opinion the root structure is more like abdounia though I know that’s not in the fauna  

It’s one of my fav finds from the matrix, alongside the few Heterodontus teeth I found 

[digit]

1 hour ago, Meganeura said:

Thanks Jess! @digit confirmed that one of my teeth at the very least was in fact Raja - it had very wide roots.

Indeed. That is one of the distinguishing features of rajid teeth--they look like they are wearing bell-bottom pants. The root lobes are splayed out and extend past the diameter of the crown.

 

 

Cheers.

 

-Ken

 

 

 

 

[Meganeura]

1 hour ago, digit said:

Indeed. That is one of the distinguishing features of rajid teeth--they look like they are wearing bell-bottom pants. The root lobes are splayed out and extend past the diameter of the crown.

 

 

Cheers.

 

-Ken

 

 

 

 

They look like wizards. Big pointy hat, long bell bottom pants. 

[digit]

Harry Potter would be proud.

 

 

Cheers.

 

-Ken

[digit]

13 hours ago, siteseer said:

The labial face of the crown of a Mustelus tooth has several vertical ridges (folds) while Rhinobatos has smooth crowns.  Rhinobatos is often a taller tooth (crown and root) than it is wide while Mustelus is generally shorter.  Rhinobatos has a distinct central uvula that extends basally and is flanked by shorter ones.  Mustelus can resemble that but the uvula is shorter and broader and there tends to be more of a cusp on the crown though it is blunt and not always distinct.  The roots of these two genera can be very similar but they are usually not well-preserved so hang onto a few with nice roots so you have reference specimens. 

All spot on!

 

Guitarfish (Rhinobatos, family Rhinobatidae) are basically smaller versions of the larger wedgefishes (Rhynchobatus, family Rhinidae) and their teeth are most similar to the larger wedgefish teeth. The guitarfish teeth are usually quite small (~1 mm) and have the pointed root lobes and enamel uvula like the larger wedgefish teeth but the uvula is usually much more elongate and distinct and flanked by shorter uvula-like droops in the enamel as mentioned above. To me the shape is quite reminiscent of a sliced button mushroom and that shape (and the size) are key to distinguishing the guitarfish teeth from the most similar wedgefish.

 

Note the two concavities in the enamel either side of the uvula in the Rhinobatos (guitarfish) tooth below and then see how this is absent on the Rhynchobatus (wedgefish) teeth below it.

 

 

 

The root lobes of both types are very distinctive with their pointed tips. The Rhynchobatus teeth are most similar to dasyatids but the presence of the uvula and the pointed tips can be used to distinguish these from the stingray teeth.

 

 

These tooth types are tiny and often confused. Hope this helps to provide some guidance on how to distinguish these species.

 

 

Cheers.

 

-Ken

[Meganeura]

1 minute ago, digit said:

All spot on!

 

Guitarfish (Rhinobatos, family Rhinobatidae) are basically smaller versions of the larger wedgefishes (Rhynchobatus, family Rhinidae) and their teeth are most similar to the larger wedgefish teeth. The guitarfish teeth are usually quite small (~1 mm) and have the pointed root lobes and enamel uvula like the larger wedgefish teeth but the uvula is usually much more elongate and distinct and flanked by shorter uvula-like droops in the enamel as mentioned above. To me the shape is quite reminiscent of a sliced button mushroom and that shape (and the size) are key to distinguishing the guitarfish teeth from the most similar wedgefish.

 

Note the two concavities in the enamel either side of the uvula in the Rhinobatos (guitarfish) tooth below and then see how this is absent on the Rhynchobatus (wedgefish) teeth below it.

 

 

 

The root lobes of both types are very distinctive with their pointed tips. The Rhynchobatus teeth are most similar to dasyatids but the presence of the uvula and the pointed tips can be used to distinguish these from the stingray teeth.

 

 

These tooth types are tiny and often confused. Hope this helps to provide some guidance on how to distinguish these species.

 

 

Cheers.

 

-Ken

I didn’t know there was a way to specify/distinguish between the two - so this is very helpful! Thanks Ken!

[digit]

 

 

 

[Notidanodon]

Does anyone have another opinion on that tope shark tooth  

[Fin Lover]

6 hours ago, digit said:

they look like they are wearing bell-bottom pants

 

5 hours ago, Meganeura said:

They look like wizards. Big pointy hat, long bell bottom pants. 

Both of those sound more intelligent than how I described the one I found: a triangle with a circle around it.  

[digit]

On 5/23/2023 at 8:01 AM, Meganeura said:

Bigger other shark teeth - Negaprion, Carcharhinus:

I believe earlier discussions on STH mentioned that Negaprion was too young of a genus for the Round Mountain Silt at STH.

 

http://www.thefossilforum.com/index.php?/topic/95769-lemon-or-black-tip-or-shark-teeth-ernst-quarry/

 

 

14 minutes ago, Fin Lover said:

Both of those sound more intelligent than how I described the one I found: a triangle with a circle around it.  

 

Hey, you probably excelled when they did the lesson on shapes in pre-school.

 

 

13 hours ago, Notidanodon said:

Great finds your sympaheseal tope shark tooth is very interesting, in my opinion the root structure is more like abdounia though I know that’s not in the fauna  

The roots on Galeorhinus are fairly distinctive in that the root is pretty much on the lingual side of the tooth--rather mustache shaped split with a large nutrient groove. While there is some similarity to Abdounia (which I believe is Paleocene-Eocene) the worn root on Daniel's symphyseal (probably parasymphyseal) is more consistent with the root on Galeorhinus.

 

 

 

Cheers.

 

-Ken

 

[Meganeura]

43 minutes ago, digit said:

I believe earlier discussions on STH mentioned that Negaprion was too young of a genus for the Round Mountain Silt at STH.

 

http://www.thefossilforum.com/index.php?/topic/95769-lemon-or-black-tip-or-shark-teeth-ernst-quarry/

 

 

 

Hey, you probably excelled when they did the lesson on shapes in pre-school.

 

 

The roots on Galeorhinus are fairly distinctive in that the root is pretty much on the lingual side of the tooth--rather mustache shaped split with a large nutrient groove. While there is some similarity to Abdounia (which I believe is Paleocene-Eocene) the worn root on Daniel's symphyseal (probably parasymphyseal) is more consistent with the root on Galeorhinus.

 

 

 

Cheers.

 

-Ken

 

Oh they’re probably just lower Carcharhinus then!