Shark Tooth Hill Micros

[chg057]

First off, I want to thank Doren for sending me a small flat rate box full of STH matrix for me to try sifting through.  

 

I still have quite a bit of fine matrix to sort through but already I've managed to find hundreds of specimens. I've found quite a few Carcharhinus, Cetorhinus, Galeorhinus, Squalus, and tons of ray teeth. When I'm finished with all the matrix, I think I'll write a follow-up post with all the nice specimens I found. 

 

I'm having a little trouble identifying various species of rays - maybe someone has a literature suggestion to help me get familiar with different tooth characteristics? From what I can tell from other posts, the features that differentiate some ray species are quite subtle and to my untrained eye, very difficult to distinguish. 

 

I wouldn't mind some ID help with these teeth in particular. Scale to the right is in mm. If you could also comment on how common/uncommon these species are and what position they are in the jaw that would be immensely helpful as well. Also, maybe someone wouldn't mind making a list of the species found at STH and rank how common they are?

 

Also, does anyone have suggestions for removing the last bit of silt/sand from the crevices in the teeth? I've tried water and gently stirring but that does not have much of an effect.

 

Thanks for your help!

 

 

[Peat Burns]

I think the second photo is Dasyatis (ray) teeth.  

 

Hopefully the STH experts will be along soon with more info.

[Angie]

The bottom tooth in the first picture looks like a Galeocerdo sp. (perhaps a posterior G. aduncus?) to me. The big tooth in the last picture might be a Carcharhinus sp. (but it's a little hard to see).

There is a species list of Shark Tooth Hill: http://www.sharktoothhill.org/index.cfm?fuseaction=news_full_view&news_id=12 , but I don't know how accurate it is.

[siteseer]

14 hours ago, Peat Burns said:

I think the second photo is Dasyatis (ray) teeth.  

 

Hopefully the STH experts will be along soon with more info.

 

 

Yes, except the bottom one in that group is a Mustelus tooth.  Mustelus is a shark genus (smoothhound shark) still living today.

[siteseer]

12 hours ago, Angie said:

The bottom tooth in the first picture looks like a Galeocerdo sp. (perhaps a posterior G. aduncus?) to me. The big tooth in the last picture might be a Carcharhinus sp. (but it's a little hard to see).

There is a species list of Shark Tooth Hill: http://www.sharktoothhill.org/index.cfm?fuseaction=news_full_view&news_id=12 , but I don't know how accurate it is.

 

 

Yes, I agree that it's a Galeocerdo posterior with a Carcharhinus tooth above it and a Carcharodon hastalis posterior above that.  I think both those teeth in the last group are Carcharhinus but it helps a lot if a poster shows both faces of a tooth with maybe a profile shot as well

 

 

[siteseer]

12 hours ago, Angie said:

The bottom tooth in the first picture looks like a Galeocerdo sp. (perhaps a posterior G. aduncus?) to me. The big tooth in the last picture might be a Carcharhinus sp. (but it's a little hard to see).

There is a species list of Shark Tooth Hill: http://www.sharktoothhill.org/index.cfm?fuseaction=news_full_view&news_id=12 , but I don't know how accurate it is.

 

 

Oh yeah, that is an old list.  Errors were pointed out to the museum years ago but no corrections were made.

[siteseer]

17 hours ago, chg057 said:

 

I wouldn't mind some ID help with these teeth in particular. Scale to the right is in mm. If you could also comment on how common/uncommon these species are and what position they are in the jaw that would be immensely helpful as well. Also, maybe someone wouldn't mind making a list of the species found at STH and rank how common they are?

 

Also, does anyone have suggestions for removing the last bit of silt/sand from the crevices in the teeth? I've tried water and gently stirring but that does not have much of an effect.

 

Thanks for your help!

 

 

 

 

 

There isn't a book about Sharktooth Hill sharks and rays.  Figuring out STH stuff requires some research on Miocene specimens elsewhere as well as on modern forms and then sharks in general.  There is a guide on elasmo.com.  Go to the Faunas tab.  Jim, Bill, and Marcel are sharp.  I've seen Jess guess wrong a few times.

 

Jess

 

 

 

 

[chg057]

Thanks all! I'll try posting some better pictures of the last two teeth.