Galeocerdo Aduncus Versus Cuvier

[AlexMcCarthyWX]

Hey everyone,

I have been trying to determine if my different tiger shark teeth are galeocerdo cuvier or aduncus, and it seems that every time I read identification guides/forums I just get more and more confused. Can anyone identify these and give me a good method of telling them apart? Too often I see that aduncus is smaller and thinner, but I am curious if there is a better way than size. Thank you very much!

Edited July 24, 2014 by AlexMcCarthyWX

[MarcoSr]

The G. cuvier have fine secondary serrations on the large serrations on the distal heal and mesial edge. The G. aduncus only have fine secondary serrations on the first few large serrations on the distal heal. However water wear can remove these finer secondary serrations from specimens and make them look more like G. aduncus. See the below pictures. G. aduncus are much smaller than G. Cuvier. In the Miocene of MD/VA, G. aduncus have a maximum size of 2cm (.8 inch). G cuvier have a broader and more robust crown and have a more strongly convex mesial cutting edge than G. aduncus.

Your first tooth might be too large to be an aduncus. I can't see the serrations or other features well enough in the pictures to really id the teeth to the species.

cuvier:

distal shoulder:

mesial edge:

aduncus:

distal shoulder:

mesial edge:

Marco Sr.

[AlexMcCarthyWX]

Thanks for your information MarcoSr, unfortunately any secondary serrations on these teeth have been warn off. I have read that the shape of the root lobes (square versus rounded) can be used to differentiate the two species, however I have seen aduncus teeth on the internet that have square lobes. Is that method of identification any good, or should I avoid that?

[MarcoSr]

Thanks for your information MarcoSr, unfortunately any secondary serrations on these teeth have been warn off. I have read that the shape of the root lobes (square versus rounded) can be used to differentiate the two species, however I have seen aduncus teeth on the internet that have square lobes. Is that method of identification any good, or should I avoid that?

Cuvier is an extant species to the Pliocene. Aduncus is a Miocene species. So the age of the formation where found can be used as an id aid. I haven't used root shape.

Marco Sr.

[Al Dente]

With a little practice the adult teeth can be fairly easy to tell apart, there is a size and shape difference, and a difference in serrations. The big problem is trying to differentiate juvenile cuvier from aduncus teeth. Unless you have pristine teeth it will be difficult.