Chondrichthyan Unknown

[minnbuckeye]

I was working through some Burlington Limestone, Mississippian looking for the Chondrichthyan fossils found within. Most primitive shark teeth in this matrix are fairly small, which is why this unknown surprised me when discovered. My suspicion is Deltodus except for the massive size. I welcome all thoughts on this ID. Unfortunately the missing pieces were not found. @Elasmohunter, this one's for you!!!!!!!!!!

 

 

 

 

 

 

[Fossildude19]

@jdp  @Archie  @JimB88

[jdp]

I've seen some extremely large Deltodus toothplates. This seems to be one of them.

[JimB88]

Sandalodus is a better fit I believe....its teeth were large.

[minnbuckeye]

Thanks for the thoughts  @jdp.

 

@JimB88, I found myself looking at images on line and kept finding the pictures from old posts composed by you. They contain great info! I too wish these fossils would be better studied. When I finish unlocking the teeth from this matrix ( 100 lbs and I am about 1/4 done) you are welcome to some, seeing your interest in them is so high!! Just let me know. Are the teeth from your area so fragile as those in the Burlington?? Touched wrong they just turn into a pile of powder.

[Archie]

Lovely tooth! Very similar to some of the Mississipian aged Cochliodontids here in Scotland like Deltoptychius, agree with @JimB88 though Sandalodus is a good match.

 

[JimB88]

11 hours ago, minnbuckeye said:

Thanks for the thoughts  @jdp.

 

@JimB88, I found myself looking at images on line and kept finding the pictures from old posts composed by you. They contain great info! I too wish these fossils would be better studied. When I finish unlocking the teeth from this matrix ( 100 lbs and I am about 1/4 done) you are welcome to some, seeing your interest in them is so high!! Just let me know. Are the teeth from your area so fragile as those in the Burlington?? Touched wrong they just turn into a pile of powder.

The teeth in this area tend to be wanna-be astronauts - one wrong tap and they zing off into the stratosphere!    Thats why I would coat the fossil in rubber cement or put a damp towel over it. Other than that, they would sometimes break, but Id just glue em' back together!. you may want to use a consolidant  as you expose them.

Edited January 25, 2022 by JimB88

[jdp]

On 1/24/2022 at 7:12 AM, JimB88 said:

Sandalodus is a better fit I believe....its teeth were large.

 

I wouldn't disagree with a Sandalodus ID either. But just want to be clear I've seen Deltodus this large or larger.

[minnbuckeye]

@jdp and @JimB88, Thanks for your input! I will label it as indeterminate, possibly Deltodus or Sandalodus. But out of curiosity, if I had a 2" pristine specimen of both side by side for comparison, how would I tell them apart????????

  

Mike

[Elasmohunter]

A colleague of mine confirmed that this is Deltodus sp. The largest Deltodus teeth that I'm aware of belong to Deltodis grandis, and they can be up to several cm across.

Oddly enough, I think that Deltodis grandis might have been synonymized with Sandalodus grandis. Or, in other words, there's room for taxonomic revision here, and Deltodus and Sandalodus can sometimes overlap, even though they shouldn't.

Great find! :)