Strange Sharktooth Hill nano tooth(?)

[ynot]

Hay hi Folks,

Got another puzzler (to Me) for ID.

Scale is in millimeters.

[ynot]

more pics...

[ynot]

more pics...

[ynot]

more pics......

[Wolf89]

Whale or basking shark?

[ynot]

11 minutes ago, Wolf89 said:

Whale or basking shark?

Basking shark was My first thought, but it is lacking carnie. All of the other basking shark teeth I have found (1000+) have pronounced carnie.

[Al Dente]

It might be a Carcharhinus symphyseal tooth. Here’s one of Marco Sr.’s photos from the phatfossil website.

[ynot]

52 minutes ago, Al Dente said:

Carcharhinus symphyseal tooth.

That does look like a good match.

Thanks Jess.

[ynot]

Hey @MarcoSr,

What is Your opinion on this tooth?

[MarcoSr]

12 hours ago, ynot said:

Hey @MarcoSr,

What is Your opinion on this tooth?

 

Tony

 

It is too bad that the tooth doesn't have its root.  That would have really helped with the id.   Looking at the crown features like the overall shape and cutting edge and how the root would have been positioned on the crown, I don't think the tooth is a Cetorhinus (Basking Shark) tooth.  However, I can't rule out a Rhincodon (Whale Shark) from the pictures although the tooth is smaller than the fossil and extant teeth that I have that range from 3.5 to 4 mm.  Your tooth crown is narrow and has a cutting edge like a whale shark tooth.  However whale shark teeth have a heel at the back of the crown.  I can't see this feature on your tooth but I can't tell if your tooth is damaged at the back of the crown.  Does your tooth have a feature like I've circled below?  If not it is definitely not a whale shark tooth.  Also, I have not heard of whale sharks from STH.

 

 

 

All this being said, a good number of Carcharhinus species have symphyseal teeth (Like those in the picture that Eric provided above) in both the upper and lower jaws that look very similar to your tooth.  Some of these symphyseal teeth would be a couple of millimeters in size like your tooth.  Some have a narrow crown like your tooth especially the alternate teeth like those shown in Eric's picture.  Some have a non-serrated cutting edge like your tooth.  Carcharhinus species are common in the STH fauna.  Although not a 100% positive id, a Carcharhinus species alternate symphyseal tooth would be my probable id.

 

Marco Sr.

[ynot]

12 minutes ago, MarcoSr said:

Your tooth crown is narrow and has a cutting edge like a whale shark tooth.  However whale shark teeth have a heel at the back of the crown.  I can't see this feature on your tooth but I can't tell if your tooth is damaged at the back of the crown.  Does your tooth have a feature like I've circled below?  If not it is definitely not a whale shark tooth. 

The tip does flatten like a whale shark tooth but has no "heel", and I could not see any cutting edge on the tooth. (the appearance of a carnie in the pictures is an illusion of the pictures.)

I agree with not whale or basking.

19 minutes ago, MarcoSr said:

  Carcharhinus species are common in the STH fauna.  Although not a 100% positive id, a Carcharhinus species alternate symphyseal tooth would be my probable id.

I think it is maybe 98% probable ID for this one.

The only other candidates I can think of are Hexanchus or Hemipristis.

 

Thanks for the informative dissertation!

 

Thanks again,

Tony

[MarcoSr]

4 hours ago, ynot said:

 I could not see any cutting edge on the tooth. (the appearance of a carnie in the pictures is an illusion of the pictures.)

 

Tony

 

Sometimes pictures are really deceiving.  From your pictures I thought I could see both cutting edges especially in the second picture.  The faint cutting edge in the picture of the Rhincodon that I posted is really there.  You can really see the cutting edge in this view of the same tooth.

 

 

 

Marco Sr.