Jump to content

Recommended Posts

Hi everyone,

I'm trying to id some very small shark teeth for an independent research paper I'm writing and am a little unsure on my ids. I took some photos of some typical specimens and was hoping to get some feedback. The scale bar is mm. I put what I think the species is with each group of photos. Any feedback and tips for differentiating these species would be greatly appreciated.

Pachygaleus.jpg

Physogaleus.jpg

Galeorhinus.jpg

Link to post
Share on other sites
Al Dente

Most of these look like Physogaleus secundus. We would need to see the labial sides to rule out some other possibilities such as Galeorhinus.

Link to post
Share on other sites

Thanks! I'll post some better pics with both sides later today. How does one tell the difference between Galeorhinus and Physogaleus?

Link to post
Share on other sites
  • Fossildude19 changed the title to Micro Stone City shark teeth
Searcher78

Don't know if this helps...…….hope it does!

Tooth Comparison.jpg

  • I found this Informative 1
Link to post
Share on other sites

Thanks!

I do have a couple questions.

Does the root bulge out on all Physogaleus teeth regardless of the jaw position?

When identifying Pachygaleus I always look for a main cusp that is much more stubby and short than the other two species, is that accurate?

Link to post
Share on other sites
Searcher78
52 minutes ago, jikohr said:

Thanks!

I do have a couple questions.

Does the root bulge out on all Physogaleus teeth regardless of the jaw position?

When identifying Pachygaleus I always look for a main cusp that is much more stubby and short than the other two species, is that accurate?

Yes, for Pachygaleus, shorter main cusp. The majority of Physogaleus teeth I have seen have protruding (thick) root. I’m not sure about all jaw positions though. The only Physogaleus I find in the areas I hunt is the “contortus”.

Link to post
Share on other sites
Al Dente

Pachygaleus and Galeorhinus have a bulge of enamel that hangs over the root on the labial side. Physogaleus doesn’t. You can see the bulge in the photos Sercher78 shared.

  • I found this Informative 1
Link to post
Share on other sites
23 minutes ago, Al Dente said:

Pachygaleus and Galeorhinus have a bulge of enamel that hangs over the root on the labial side. Physogaleus doesn’t. You can see the bulge in the photos Sercher78 shared.

I read that elsewhere and was kind of confused by it. Is the enamel bulge near the ends? Because I saw a slight bulge in the center of the enamel as well on Physogaleus. Also Here are better pictures that show all the labial faces.

Pachygaleus.jpg

Physogaleus.jpg

Galeorhinus.jpg

Link to post
Share on other sites
Al Dente
On 3/3/2021 at 5:19 PM, jikohr said:

Is the enamel bulge near the ends?

 

It should go all the way across the tooth. Here is the only one of your teeth that I see with an enamel bulge.

 

 

overhang.JPG

Link to post
Share on other sites
Al Dente

Here are many examples of Middle Eocene Physogaleus secundus. These are from the Claiborne Group of Alabama, the same age as your teeth. I've included a picture of the reference that this picture came from. It's a good paper.

 

 

physogaleus1.JPG

 

 

physogaleus2.JPG

  • I found this Informative 2
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...