Oligocene-Miocene Shark Tooth Identification - Trigonotodus? Isurus?

[Sharks of SC]

Hey Folks,

I found this tooth yesterday at a dredge spoil site near Charleston SC (see post http://www.thefossilforum.com/index.php?/topic/37010-dredge-spoiled/). Material from this site is from many reworked layers, with finds ranging from Oligocene to Pliestocene epochs. The shark teeth are mostly from the Oligocene to Miocene.

This tooth is peculiar - it has characteristics of an I. hastalis mako, but is very short with minute cusps. I considered Trigonotodus sp. as a candidate as well, but this tooth doesn't look quite like any examples I could find online.

Any insight is much appreciated!

Happy hunting,

CBK

[Sharks of SC]

And the back..

[MikeDOTB]

It's not a mako at all. A. Grandis or Trigonotodus. I'm not sure those are cusps either or just worn enamel. Nice tooth either way. I'm amazed by the numbers of giant threshers you find!

[Gizmo]

For comparison :

[Sharks of SC]

Hey Mike,

Thanks! I found this other fragmented tooth that I'm a little more certain of being a Trigonotodus alteri. If the first tooth turns out to be one too, that would make two specimens in the same day after having not found one in 15 years of hunting.

[njcreekhunter]

I agree with MikeDOTB, either Alopias Grandis or Trigonotodus alteri, very nice find. I think I gotta go with Trigonotodus.

[Sharks of SC]

For comparison :

Picture 20.png Picture 19.png

Hey Gizmo, thanks for the additional images. So...what's your take? My tooth seems more broad and flat with less-pronounced cusp(s) than your examples.

[Sharks of SC]

I agree with MikeDOTB, either Alopias Grandis or Trigonotodus alteri, very nice find. I think I gotta go with Trigonotodus.

Thanks Sharktoothboy! Nowhere near as nice as your recently-posted example, but I'm glad to have found it!

[Gizmo]

On the first one I'm leaning toward Trigonotodus alteri, the second I'm pretty sure is Trigonotodus alteri.

[isurus90064]

I realize this thread is older, but there's been some thresher talk on the following thread (post 603 - 615):

http://www.thefossilforum.com/index.php?/topic/2380-extraordinary-common-teeth/page-31

Your tooth is definitely Trigonotodus alteri. Maybe your tooth represents a transition.

[siteseer]

CBK,

Definitely an oddball tooth. Great find. Just eyeballing it, your tooth looks to be maybe just over an inch. What is the size?

Jess

Hey Folks,
I found this tooth yesterday at a dredge spoil site near Charleston SC (see post http://www.thefossilforum.com/index.php?/topic/37010-dredge-spoiled/). Material from this site is from many reworked layers, with finds ranging from Oligocene to Pliestocene epochs. The shark teeth are mostly from the Oligocene to Miocene.
This tooth is peculiar - it has characteristics of an I. hastalis mako, but is very short with minute cusps. I considered Trigonotodus sp. as a candidate as well, but this tooth doesn't look quite like any examples I could find online.
Any insight is much appreciated!
Happy hunting,
CBK
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