A few micro shark teeth

[thelivingdead531]

Hey everyone! Back in June I got a huge bag of matrix from Florida that was abundant in tiny shark teeth. I've been struggling to identify them since they are so small, but for Christmas I received a digital microscope so I took a few shots to see if you could help me identify them. I'm sorry if the shots are too blurry, I'm still learning how to use the microscope. The matrix is either Pleistocene or Miocene, I'm not sure which. The squares are 5x5 mm.

[thelivingdead531]

[thelivingdead531]

[hemipristis]

I propose:

Tooth 1 &2: Sphyrna Sp., hammerhead

Tooth 3: Rhizoprionodon sp., sharp nose shark

 

[Thomas.Dodson]

7 minutes ago, hemipristis said:

I propose:

Tooth 1 &2: Sphyrna Sp., hammerhead

Tooth 3: Rhizoprionodon sp., sharp nose shark

 

I second this.

[thelivingdead531]

Thank you both! You sent me in the right direction and when I looked them up I have to agree with you. 

[minnbuckeye]

Fossilguy.com has this on his website: 

 

 

@hemipristis, I am NOT questioning the identification mentioned above. I know nothing about shark's teeth, but am interested in the Florida micro mix in that I must ID my Cookie cutter creek micromatrix teeth. Hopefully a hammerhead will be there! As I look at the teeth, 1 and 3 have deep nutrient grooves. 2 does not. None seem to have the convex shoulder. So....... do hammerheads have significant variability, so much that fossilguy's rules are not enough to go by? My apologies to @thelivingdead531 for getting off topic.

 

Mike

 

[ThePhysicist]

33 minutes ago, minnbuckeye said:

As I look at the teeth, 1 and 3 have deep nutrient grooves. 2 does not. None seem to have the convex shoulder. So....... do hammerheads have significant variability, so much that fossilguy's rules are not enough to go by?

My "expertise" is in Cretaceous teeth, however I do have some knowledge about hammerheads since I found one and needed to ID it. I don't think 1 & 2 are Sphyrna sp. 1 looks to have serrations on the shoulder; only teeth from a couple of species can have serrations, and none that proportionally large (to my knowledge). 2 doesn't have a nutrient groove as @minnbuckeye observed. I can't offer an alternative identification, I can only say I don't think they're hammerheads. 

[Thomas.Dodson]

1 hour ago, minnbuckeye said:

Fossilguy.com has this on his website: 

 

 

@hemipristis, I am NOT questioning the identification mentioned above. I know nothing about shark's teeth, but am interested in the Florida micro mix in that I must ID my Cookie cutter creek micromatrix teeth. Hopefully a hammerhead will be there! As I look at the teeth, 1 and 3 have deep nutrient grooves. 2 does not. None seem to have the convex shoulder. So....... do hammerheads have significant variability, so much that fossilguy's rules are not enough to go by? My apologies to @thelivingdead531 for getting off topic.

 

Mike

 

Sphyrna vary by series of tooth and species. I've seen indistinct nutrient grooves in Sphyrna like #2 before. The posterior teeth seem to have less pronounced grooves and it's probably worn anyway.

 

I could be convinced #1 is something like a worn Galeorhinus because of the cusplets but I've seen some Sphyrna approach that level. They're usually more pronounced on Galeorhinus from what I've seen also.

 

These are all Sphyrna teeth, although different species.

[Al Dente]

I wouldn’t be surprised if all three teeth were Carcharhinus. Carcharhinus posterior teeth can look identical to some Sphyrna and Rhizoprionodon teeth. Age and gender also adds to the variation of tooth morphology in these teeth. Sorry for the blurry photos.

 

 

[MarcoSr]

53 minutes ago, Al Dente said:

I wouldn’t be surprised if all three teeth were Carcharhinus. Carcharhinus posterior teeth can look identical to some Sphyrna and Rhizoprionodon teeth. Age and gender also adds to the variation of tooth morphology in these teeth. Sorry for the blurry photos.

 

I agree with Eric.  My first impressions were Carcharhinus teeth.

 

Marco Sr.