Shark teeth ID requested!

[Lmsolliday]

New collector seeking help with ID…I tried to research on my own and seem to only get more confused.  Trying to learn!

[DatFossilBoy]

Hey!

Top row from left to right: C.leucas (bull shark), Hemipristis serra, C.leucas

Bottom row: not sure (hastalis?), carcharhinus x3

 

I could be wrong so I may stand corrected 

[Lmsolliday]

Thank you!  I was thinking Hemispristis on number 2 - my first one!

[Meganeura]

Bottom row on the left is a Lemon shark (Negaprion sp.) but the rest, besides the Hemi, are carcharhinus!

[debivort]

My first thought on the bottom left was retroflexus. Lemon shark teeth tend to be small. How large is this tooth? 

I also wonder if the second on the bottom row is a contortus.

[Lmsolliday]

Sorry!  I realize now I didn’t include anything to show size in the picture.  I’ll do better in the future, but the light-colored one on the bottom left is just a smidge over a 1/2 inch long.  Definitely not a lemon shark - I feel like that’s the only kind I’m sure of…that and sand tiger!

[debivort]

5 minutes ago, Lmsolliday said:

Sorry!  I realize now I didn’t include anything to show size in the picture.  I’ll do better in the future, but the light-colored one on the bottom left is just a smidge over a 1/2 inch long.  Definitely not a lemon shark - I feel like that’s the only kind I’m sure of…that and sand tiger!

That would be a honker lemon. So yeah, I think it's a mako (possibly retroflexus) or hastalis. Hard to tell with the root that incomplete.

[debivort]

36 minutes ago, debivort said:

I also wonder if the second on the bottom row is a contortus.

After looking at the photo properly magnified, I now think it's a Carcharinus, as others suggested, but with the pathology illustrated here: 

[Lmsolliday]

Very interesting!  I was first wondering if the one on the top right was pathological, but looking closer, maybe bite damage?

[debivort]

7 minutes ago, Lmsolliday said:

Very interesting!  I was first wondering if the one on the top right was pathological, but looking closer, maybe bite damage?

I agree it's probably feeding damage.

[Meganeura]

13 hours ago, debivort said:

That would be a honker lemon. So yeah, I think it's a mako (possibly retroflexus) or hastalis. Hard to tell with the root that incomplete.

Maybe I'm insane - I've found a bunch of lemons that big! I don't think we get retroflexus here in Florida.

[Meganeura]

@debivort I stand by the lemon shark ID. Here’s 10 examples that are easily over a half-inch from my own collection. Ruler is in inches:

 

for comparison - my smaller makos that may possibly be confused with lemon. Note the top of the blade gets much wider as it meets the root, and also the root-blade boundary is very flat - something a lemon shark doesn’t do, and also that @Lmsolliday’S tooth in question doesn’t do:

Edited September 21, 2022 by Meganeura

[hemipristis]

I'm with @Meganeura on the IDs excepting the lower left.  I just don't know.  

Question:  are the top row, farthest left tooth and bottom row, 2nd from left very thin in cross-section?  If so, they are likely Carcharhinus plumbeus, the sandbar shark.

Edited September 22, 2022 by hemipristis

[debivort]

3 hours ago, Meganeura said:

 I stand by the lemon shark ID. Here’s 10 examples that are easily over a half-inch from my own collection. Ruler is in inches:

I'm persuaded! I think I had a brain blip about the actual scale of 1/2''. However, in my defense, here are the hastalis and mako teeth in my collection I was thinking were a close match (scale bar is 1 inch)

 

I wonder if it's just luck that I've only ever found small lemons, or whether they are generally smaller in SC than FL:

 

[Meganeura]

Just now, debivort said:

I'm persuaded! I think I had a brain blip about the actual scale of 1/2''. However, in my defense, here are the hastalis and mako teeth in my collection I was thinking were a close match (scale bar is 1 inch)

 

I wonder if it's just luck that I've only ever found small lemons, or whether they are generally smaller in SC than FL:

 

I think I actually remember reading somewhere that lemons ARE smaller in SC - but I can't remember where, so take that with a grain of salt.

As far as the Mako's go - yeah, the lowers do get to be pretty similar looking, but they've got the same root thing going on. Lemons have a "lip" where the root comes down onto the blade, whereas the blade on Makos comes up to meet the root, if that makes sense! At least in my experience, anyway.

[Lmsolliday]

Interesting.  The reason I dismissed lemon on that one is it’s so thin and flat compared to every other lemon I’ve ever seen.  But then I am not experienced enough to know the nuances between most teeth.  More pictures of it below.

[Meganeura]

Just now, Lmsolliday said:

Interesting.  The reason I dismissed lemon on that one is it’s so thin and flat compared to every other lemon I’ve ever seen.  But then I am not experienced enough to know the nuances between most teeth.  More pictures of it below.

That actually solidifies it as lemon for me - the "lip" I mentioned is much clearer. Also I think tooth position has an effect on how thick shark teeth are? But regardless that's a pretty standard thickness for lemons here. They're not all that thick in my experience!

[debivort]

Lemons are quit cylindrical in SC. These new pictures make this tooth seem even more different than my lemons, I have to say. But the regional variation is probably real.

[Lmsolliday]

It’s very different from any lemon I have or have seen.  Every one I’ve seen is very cylindrical…not quite like a sand tiger, but more like that shape than this wider, flatter one.  The six bottom ones in the picture below are what I believed to be lemon, compared to the tooth we’re discussing.  Curious!

Edited September 21, 2022 by Lmsolliday

[hemipristis]

16 hours ago, Lmsolliday said:

It’s very different from any lemon I have or have seen.  Every one I’ve seen is very cylindrical…not quite like a sand tiger, but more like that shape than this wider, flatter one.  The six bottom ones in the picture below are what I believed to be lemon, compared to the tooth we’re discussing.  Curious!

Except the furthest left tooth, the remaining teeth in the bottom row are Carcharinifom teeth from the lower jaws. The order Carcharhiniforms includes all of the Carcharhinus sharks, as well as lemon sharks and others.

 

The singular tooth in the top row however, is an upper tooth.  At first I thought perhaps Carchroides catticus, but it is slightly curved (which C. catticus teeth generally are not). and the root intrudes too far down the blade. 

Edited September 22, 2022 by hemipristis

[hemipristis]

17 hours ago, Meganeura said:

I think I actually remember reading somewhere that lemons ARE smaller in SC - but I can't remember where, so take that with a grain of salt.

 

16 hours ago, debivort said:

Lemons are quit cylindrical in SC. These new pictures make this tooth seem even more different than my lemons, I have to say. But the regional variation is probably real.

In looking at the healthy numbers of lemon shark teeth that I've collected or bought, I feel confident in stating that lemon shark teeth get larger as one proceeds south along the US East Coast.  Florida has some real honkers 1"+, but I have not seen any which approach that size from the Carolinas, and most aren't but 2/3 that size 

[Meganeura]

6 minutes ago, hemipristis said:

Except the furthest left tooth, the remaining teeth in the bottom row are Carcharinifom teeth from the lower jaws. The order Carcharhiniforms includes all of the Carcharhinus sharks, as well as lemon sharks and others.

 

The singular tooth in the top row however, is an upper tooth.  At first I thought perhaps Carchroides catticus, but it is slightly curved (which C. catticus teeth generally are not). and the root intrudes too far down the blade. 

I’ve also never seen any C. catticus teeth here - though I hunt in Central Fl, not North, so no Oligocene down here. Couple sand tigers that look similar though. 

[hemipristis]

Just now, Meganeura said:

I’ve also never seen any C. catticus teeth here - though I hunt in Central Fl, not North, so no Oligocene down here. Couple sand tigers that look similar though. 

I've seen only one, and snatched it up at an auction as fast as I could type because it was the only one I've ever seen from FL

[Meganeura]

39 minutes ago, hemipristis said:

I've seen only one, and snatched it up at an auction as fast as I could type because it was the only one I've ever seen from FL

North Fl I assume?

[debivort]

2 hours ago, hemipristis said:

The singular tooth in the top row however, is an upper tooth.  At first I thought perhaps Carchroides catticus, but it is slightly curved (which C. catticus teeth generally are not). and the root intrudes too far down the blade. 

Sorry, now I'm confused. Isn't this the same tooth you thought was a lemon shark earlier in the thread?