Tiny Mystery Shark Tooth from Rattlesnake Creek

[digit]

I recently collected some micro-matrix from Rattlesnake Creek in Gainesville. See my other posting if you want to read more about that here: http://www.thefossilforum.com/index.php?/topic/58470-rattlesnake-creek-rendezvous/?p=622403

This morning while sorting through the micro-matrix I spotted an unusual (for me) tiny shark tooth that has me guessing. This little one is only about 4.5 mm across the base of the root and around 5 mm along the long edge of the blade. It is novel solely due to the presence of the side cusp(s). There is an obvious side cusp on the side toward which the main cusp angles and there appears to be a bit up a "bump" in the enamel at the other side of the tooth that is subtle but apparent when looking at the tooth under magnification but, unfortunately, does not photograph very well. Basically, there appears to be a faint "notch" at the base of the long edge of the main cusp and the enamel is ever so slightly raised past this notch. The tooth does not really resemble the tiny Tiger Shark or Sand Tiger teeth which I know to have additional side cusps. The root is too flat and not as U-shaped as I'd expect for a posterior Sand Tiger tooth. It also doesn't seem to have the correct "bend" that I'm used to for the various species of Tiger Shark teeth that I'm familiar with from locations in South Florida.

Any help with a possible identification on this tiny little mystery tooth would be welcome and educational--for me and possibly for other readers.

Cheers.

-Ken

[Grimlock]

Hey Ken. To me your tooth most resembles an upper night shark (Carcharhinus signatus) tooth. This is a small species that is pretty common around here.The one side is a little broken, so it hurts the id a little bit. That is the best guess I have for you. Very interesting little tooth

[Al Dente]

It will be difficult to identify this tooth because much of it is missing and there are many types that look similar. It might be some type of Triakid or Hemigaleid tooth. Sometimes Physogaleus can look similar to this as well as Chaenogaleus. Not much published on Florida teeth so it could be something undescribed.

[Khyssa]

I would have to look through my jar of Rattlesnake creek teeth to be completely sure but I don't think I've come across one looking quite like that one before. And I usually inspect all the teeth I collect from there so that I can admire the colors.

[digit]

It will be difficult to identify this tooth because much of it is missing and there are many types that look similar. It might be some type of Triakid or Hemigaleid tooth. Sometimes Physogaleus can look similar to this as well as Chaenogaleus. Not much published on Florida teeth so it could be something undescribed.

Very interesting. I often wonder just how much of the tooth is missing when teeth have a blunt end on the side of the root. I've always assumed that it is just the corner getting knocked-off but I guess there could be more to the tooth. Assuming that the very worn nutrient groove should be roughly in the middle of the tooth and that the other end of the tooth tapers to a point without any sign of breakage it would seem to me that there might not have been that much more of the tooth on the end with the broken root.

I've done a little google image searching and I do see some similarities to some species of the family Triakidae as shown in this PDF available online: http://agro.icm.edu.pl/agro/element/bwmeta1.element.agro-article-8dff47a3-efa4-44c1-8d1e-f8150633c087/c/app53-433.pdf

I may pass this image past Dr. Hulbert and see if it piques his interest enough to comment.

When I first saw it I thought it unusual. Glad to at least have confirmation that it is not something blatantly common that I am just not aware of yet. Thanks for the feedback. You can bet I'll keep my eyes peeled for anything else that looks similar while I'm sorting through my Rattlesnake Creek micro-matrix.

Cheers.

-Ken