Shark Tooth ID Help

[hokietech96]

Hi.  Hope everyone had a great week.  I found this tooth this morning as I continue to go through more of the Lee Creek Matrix.  I am somewhat confident that this is a Finetooth shark - Carcharhinus Isodon.  I wondering if someone can confirm if I am correct on this one.  Thank you so much for any feedback.

 

[hokietech96]

@Al Dente @MarcoSr have either you found a tooth like this from Lee Creek?

[Al Dente]

3 hours ago, hokietech96 said:

@Al Dente @MarcoSr have either you found a tooth like this from Lee Creek?

I have many like this. It could be C. isodon but lower and posterior Carcharhinus teeth are difficult to identify.

[hokietech96]

Thanks for looking. I was hoping it was C. Isodon. It would be my first

[MarcoSr]

6 hours ago, hokietech96 said:

@Al Dente @MarcoSr have either you found a tooth like this from Lee Creek?

 

I have a good number of teeth like your specimen from Lee Creek matrix.  Lower Carcharhinus teeth are very similar.  The fact that your tooth doesn't look serrated in your pictures eliminates a lot of Carcharhinus species.  C. isodon is a definite possibility for an ID for your tooth.  However, there are other possibilities.  Below are two extant Carcharhinus signatus (Night Shark) lower teeth (both 8 mm) to compare your tooth to for example.

 

 

 

 

 

 

 

Marco Sr.

[hokietech96]

@MarcoSr thanks for you feedback and the pictures. I honestly never heard of C. Signatus. Thanks for teaching me something!  I don’t think I saw that on elasmo. The teeth look very similar. The blade on mine curves on mine. It looks like your is more straight. Does that make a difference?

[MarcoSr]

2 hours ago, hokietech96 said:

@MarcoSr thanks for you feedback and the pictures. I honestly never heard of C. Signatus. Thanks for teaching me something!  I don’t think I saw that on elasmo. The teeth look very similar. The blade on mine curves on mine. It looks like your is more straight. Does that make a difference?

 

Tooth position in the jaw can change the crown angle.  Here is another extant Carcharhinus signatus tooth with more of a curve.

 

 

 

 

 

 

Marco Sr.

[hokietech96]

Thanks. It looks like a match to me. 

[MarcoSr]

6 hours ago, hokietech96 said:

Thanks. It looks like a match to me. 

 

Unfortunately I don't have an extant C. isodon jaw or teeth to compare your tooth too.  I have lots of publications that show jaws and teeth but the pictures just don't let me compare the teeth very well.  Elasmo only shows upper C. isodon teeth in its Lee Creek fauna discussion.  It is still very possible that your tooth is a lower C. isodon.  However, there are other possibilities.  Elasmo doesn't list C. signatus in the Lee Creek fauna.  But that doesn't mean that it isn't there.  It could be rare.  I help Dr. Robert Weems expand vertebrate fauna lists by finding unreported species in matrix from different faunas.  So I'm used to finding species that are not reported from a fauna.  However, if in doubt on an ID, it is best to go with a reported ID if that is a good possibility from the tooth features versus an unreported ID that also a possibility.

 

Marco Sr.

[hokietech96]

@MarcoSrThanks for your insight.  I did a little research on the finetooth and it actually brought up your C. Signatus:

 

The finetooth shark was originally described as Carcharias (Aprionodon) isodon by French zoologist Achille Valenciennes, in Müller and Henle's 1839 Systematische Beschreibung der Plagiostomen. The type specimen is a 65-cm (26-in) juvenile male, possibly caught off New York. This species was later moved to the genus Carcharhinus.^[2] The specific epithet isodon means "equal teeth" in Greek, and refers to the similar number of teeth in the upper and lower jaws.^[3] This species may also be referred to as the eventooth shark, smoothtooth shark, or night shark (usually used for C. signatus).^[4]