STH hastalis or planus

[fossilsonwheels]

I have had this STH tooth for awhile but I can not identify it. I have assumed it has to be either a hastalis or planus. When I first got the large group of teeth that this tooth was in, I set aside as I thought it might be Parotodus. I quickly talked myself out of that ID.

I talked myself into hastalis or planus. 

I have looked at teeth in my collection and can’t find an exact match. I checked Elasmo and same story. My best guess is lower planus. 

It is just over 1” on the diagonal, pretty thick root. 

 

Any thoughts ???

[MrR]

I have a lower from STH that has a hefty root and accented curvature like that. I seem to remember it being said that the lowers are difficult, if not impossible, to tell apart between hastalis and planus. But I'll defer to the more experienced on whether or not that's true. Cheers.

 

[fossilsonwheels]

On 11/3/2020 at 7:16 AM, MrR said:

I have a lower from STH that has a hefty root and accented curvature like that. I seem to remember it being said that the lowers are difficult, if not impossible, to tell apart between hastalis and planus. But I'll defer to the more experienced on whether or not that's true. Cheers.

 

I have some lowers that are clearly one or the other but this one has me stumped. 

[PrehistoricWonders]

@Al Dente 

[Al Dente]

There is some discussion on the difference between planus and hastalis lowers here- http://www.thefossilforum.com/index.php?/topic/36189-isurus-hastalis-or-isurus-planus/

[JBMugu]

I think it's a thick crowned planus lower, if it was a paratodus it would have more of a curve in the blade. I see all kinds of wired variations on the STH teeth. My theory is sharks are like people, we are all the same but also very different. One day I'll make a post showing all the variations...

[fossilsonwheels]

On 11/5/2020 at 9:05 PM, JBMugu said:

I think it's a thick crowned planus lower, if it was a paratodus it would have more of a curve in the blade. I see all kinds of wired variations on the STH teeth. My theory is sharks are like people, we are all the same but also very different. One day I'll make a post showing all the variations...

Hi Jesse

I have been leaning toward planus so we’ll go with that. It’s a good theory. I think you should post of your teeth !!! 

 

[fossilsonwheels]

On 11/5/2020 at 1:09 AM, Al Dente said:

There is some discussion on the difference between planus and hastalis lowers here- http://www.thefossilforum.com/index.php?/topic/36189-isurus-hastalis-or-isurus-planus/

Thank you that is an informative post !

[JBMugu]

3 hours ago, fossilsonwheels said:

Hi Jesse

I have been leaning toward planus so we’ll go with that. It’s a good theory. I think you should post of your teeth !!! 

 

Is that one of the ones I sent you?