Chomatodus? Mississippian fish teeth ID

[Collector9658]

I decided to stop by and check out a few road cuts while traveling through the St. Louis area and found what I believe are a couple of fish teeth. I'm not certain, but all of their features lead me to believe they are fish teeth. They were both found loose of rock and close by each other as seen in the first photo. While they very in size and shape, I believe it is probable they are from the same type of animal. The rock seems to be Mississippian in geologic age, though I'm unsure of the geologic formation they eroded out from. This isn't territory I am familiar with, so I appreciate anyone's expertise on the matter!

Edited July 19, 2023 by Collector9658

[Al Dente]

It looks exactly like a Devonian Ptyctodus jaw. Any chance you were in Devonian deposits? https://www.google.com/search?q=ptyctodus&sxsrf=AB5stBi4bsQV8CVqHIBKXE5TQxR5j1h-Yw:1689791266027&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjDr5-Bs5uAAxU3MDQIHQ81Di4Q_AUoAXoECAIQAw&biw=1355&bih=660&dpr=1

Edited July 19, 2023 by Al Dente

[connorp]

Hm interesting. These look more like ptyctodont (placoderms) dental plates to me, which would mean Devonian. St. Louis area is mostly Mississippian and Ordovician, but there are Devonian outcrops to the west. Not sure exactly where you were. If you could provide more specific location details that would help.

[Collector9658]

8 hours ago, Al Dente said:

It looks exactly like a Devonian Ptyctodus jaw. Any chance you were in Devonian deposits? https://www.google.com/search?q=ptyctodus&sxsrf=AB5stBi4bsQV8CVqHIBKXE5TQxR5j1h-Yw:1689791266027&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjDr5-Bs5uAAxU3MDQIHQ81Di4Q_AUoAXoECAIQAw&biw=1355&bih=660&dpr=1

I think you are correct. Some photos I looked at online look almost identical to these teeth. They were found around the bottom of the road cut eroded out, so it is very possible and likley they could be Devonian.

[Collector9658]

9 hours ago, connorp said:

Hm interesting. These look more like ptyctodont (placoderms) dental plates to me, which would mean Devonian. St. Louis area is mostly Mississippian and Ordovician, but there are Devonian outcrops to the west. Not sure exactly where you were. If you could provide more specific location details that would help.

I found these teeth along the I-55 roadcut in Jefferson county. The USGS does mention Devonian outcrops being in the county. I think you and Al Dente are both correct about Ptyctodus which would be exciting if so. They sure do look like ptyctodont teeth I saw online. Another thing I noted but forgot to mention were how strong and robust the teeth are,  especially compared to any other Pennsylvanian or Mississippian tooth I've collected which are always fragile.

Edited July 20, 2023 by Collector9658

[connorp]

2 hours ago, Collector9658 said:

I found these teeth along the I-55 roadcut in Jefferson county. The USGS does mention Devonian outcrops being in the county. I think you and Al Dente are both correct about Ptyctodus which would be exciting if so. They sure do look like ptyctodont teeth I saw online. Another thing I noted but forgot to mention were how strong and robust the teeth are,  especially compared to any other Pennsylvanian or Mississippian tooth I've collected which are always fragile.

Maybe @pefty is familiar with this site and can comment. I know he has found ptyctodont dental plates before in Missouri.

[Collector9658]

9 hours ago, connorp said:

Maybe @pefty is familiar with this site and can comment. I know he has found ptyctodont dental plates before in Missouri.

If so, that could be a huge help. Devonian rock and St. Louis are both things I have minimal experience with. I'm pretty excited to have found something new to me, and so different from what I usually find.

[pefty]

Great post, and thanks for the tag @connorp.

 

Yes to ptyctodont! and yes to Devonian. My understanding is that these weather out of the Bushberg Sandstone, a poorly exposed Upper Devonian (Famennian) unit that may not be thick in most of the places it's exposed, sandwiched between a monstrous Ordovician section and a monstrous Mississippian section. But still, it's there! I recall finding one of these sitting loose literally on the upper bounding surface of the Ordovician rocks at a Jefferson County outcrop, and being confused as to how a fish made it into the Ordovician. Now I know better   Anyway, I think this occurrence is noted in various Missouri publications (E. B. Branson was big on the Missouri Devonian and big on fish), but I don't know that these ptyctodonts have ever been properly described, maybe because they're so weathered from rolling around for so long prior to final burial. Fwiw the ones I have look very much like the ones you found.

 

Swing by St Louis again sometime and let me know, and we can try to pinpoint the Bushberg source beds if you like.

 

 

 

[Collector9658]

3 hours ago, pefty said:

Great post, and thanks for the tag @connorp.

 

Yes to ptyctodont! and yes to Devonian. My understanding is that these weather out of the Bushberg Sandstone, a poorly exposed Upper Devonian (Famennian) unit that may not be thick in most of the places it's exposed, sandwiched between a monstrous Ordovician section and a monstrous Mississippian section. But still, it's there! I recall finding one of these sitting loose literally on the upper bounding surface of the Ordovician rocks at a Jefferson County outcrop, and being confused as to how a fish made it into the Ordovician. Now I know better   Anyway, I think this occurrence is noted in various Missouri publications (E. B. Branson was big on the Missouri Devonian and big on fish), but I don't know that these ptyctodonts have ever been properly described, maybe because they're so weathered from rolling around for so long prior to final burial. Fwiw the ones I have look very much like the ones you found.

 

Swing by St Louis again sometime and let me know, and we can try to pinpoint the Bushberg source beds if you like.

 

 

 

Your teeth do look the same. I'll have to go back there some day and really look for a sandstone layer. I never would have imagined I would find Devonian fish teeth in Missouri. I am overjoyed my initial thoughts were incorrect. Thank you everyone for the help!

[Collector9658]

On 7/20/2023 at 6:51 PM, pefty said:

Great post, and thanks for the tag @connorp.

 

Yes to ptyctodont! and yes to Devonian. My understanding is that these weather out of the Bushberg Sandstone, a poorly exposed Upper Devonian (Famennian) unit that may not be thick in most of the places it's exposed, sandwiched between a monstrous Ordovician section and a monstrous Mississippian section. But still, it's there! I recall finding one of these sitting loose literally on the upper bounding surface of the Ordovician rocks at a Jefferson County outcrop, and being confused as to how a fish made it into the Ordovician. Now I know better   Anyway, I think this occurrence is noted in various Missouri publications (E. B. Branson was big on the Missouri Devonian and big on fish), but I don't know that these ptyctodonts have ever been properly described, maybe because they're so weathered from rolling around for so long prior to final burial. Fwiw the ones I have look very much like the ones you found.

 

Swing by St Louis again sometime and let me know, and we can try to pinpoint the Bushberg source beds if you like.

 

 

 

Today on my way driving home, I stopped by that same roadcut hoping rain from last week would help expose more if they were there. I found 3 more ptyctodont teeth at that cut. Any idea if these could have came from the same fish? I would suppose there isn't a way to know for certain when finding them loose? Next time I'm in the St. Louis area, I'll reach out to you on here and see if you want to check out the specific spot.