Gomphothere Ivory Schreger angle?

[darrow]

Anyone know of or have information on Gomphothere Ivory Schreger angle?

[digit]

This paper might be of some help.

 

 

Cheers.

 

-Ken

Schreger Lines.pdf

[darrow]

3 hours ago, digit said:

This paper might be of some help.

 

 

Cheers.

 

-Ken

Schreger Lines.pdf

Excellent paper unfortunately they didn't include gomphothere in their analysis.  

[digit]

I'll try to remember to ask Richard Hulbert if he knows what angle is associated with the Montbrook gomph here in Florida.

 

 

Cheers.

 

-Ken

[Planko]

What about?

 

https://www.fws.gov/lab/ivory_natural.php#:~:text=Polished cross-sections of elephant,be divided into two categories.

[digit]

Same info pulled from the previously listed PDF (but in website form). Still don't include the earlier Miocene gomphotheres.

 

 

Cheers.

 

-Ken

[abyssunder]

Do you think you have a Gomphothere tusk fragment showing the Schreger lines? If yes, can we see it? 

[darrow]

41 minutes ago, digit said:

Same info pulled from the previously listed PDF (but in website form). Still don't include the earlier Miocene gomphotheres.

 

 

Cheers.

 

-Ken

The piece I'm trying to identify is actually from late Pleistocene dredge spoils, Galveston Bay, Beaumont formation.  I've collected more than 10 mammoth teeth (~50% complete) from the site; 1 piece of a gomphothere tooth; 0 mastodon.  I the schreger angle of piece of ivory I recently collected is ~135 degrees so clearly not mammoth.  It's either the first piece of mastodon material I've collected from this location or it's the 2nd piece of Gomphothere.  Either case is a bit unusual which is why I'm trying to to determine which it is.

 

[darrow]

51 minutes ago, abyssunder said:

Do you think you have a Gomphothere tusk fragment showing the Schreger lines? If yes, can we see it? 

hmmm...  I think I have a tusk fragment that is not mammoth.   I would normally give it a high probability of being mastodon except that I have a piece of gomphothere from the same location.

 

I'll try to get a macro picture of the Schreger lines and post it shortly.

[darrow]

Schreger lines are visible in the polished section.   They are easier to see if you step back about 10 feet from your computer screen.

 

Sorry about the poor quality of the photo, its a cell phone picture with oblique lighting from a headlight I happened to have handy.  

[abyssunder]

On 1/31/2021 at 6:24 PM, darrow said:

Schreger lines are visible in the polished section.   They are easier to see if you step back about 10 feet from your computer screen.

 

Sorry about the poor quality of the photo, its a cell phone picture with oblique lighting from a headlight I happened to have handy.  

May be the below diagram on help?

 

[darrow]

 

Unfortunately no Gomphotheres  .  

[darrow]

This is Cuvieronius which I recently learned survived in Texas until as recently at 24,000 years ago based on remains discovered near Austin, TX.

https://en.wikipedia.org/wiki/Cuvieronius#/media/File:Cuvieronius_hyodon_1.JPG

 

Anyone know if these spiral striations on the surface of this tusk are diagnostic for Gomphothere? 

 

[darrow]

I ask because this tusk fragment has a peculiar surface pattern I've not seen before on mastodon or mammoth tusk.  It on the right side of this picture and reminds me of the longitudinal scalloped pattern on a Roman column...

 

 

[Shellseeker]

So,

I have found Gomph tusks.  I do not think that I have seen spiraling lines, but there seem to be straight lines on my Gomph tusks... I have seen so few of these documented in scientific papers , that it is very difficult to get a pattern. 

 

There is a lot of material in old threads:

There is a decent photo here of the schreger lines in this one.

http://www.thefossilforum.com/index.php?/topic/52037-gomphothere-tusk/

Here is one of mine: Rynchotherium.  13.6 -3.6 myas

I see straight lines on the outside of the tusk.

 

Here is one unbroken, I believe is Cuvieronius,  but matrix and its unbroken state makes getting Schreger lines almost impossible , but once again straight , not spiral lines.

[digit]

9 hours ago, darrow said:

That's a really odd looking piece. How do you know this is a piece of tusk? Is there more diagnostic features in the cross-section? Most of my tusk fragments from the Peace River vaguely resemble petrified wood with some faint linear striations and curved layers in cross section. Proboscidean teeth apparently grow with a cone-in-cone sort of layering (picture the disposable stacked conical paper cups at a water cooler). I'd have never taken the piece above for tusk material but then I don't have it in hand to inspect closely.

 

The Miocene Rhynchotherium sp. gomphothere we have here at the Montbrook site has interesting tusks as they have an enameled strip that runs along one side.

 

Cheers.

 

-Ken

 

    

 

    

 

[IsaacTheFossilMan]

Hello!

This area isn't really my expertise - I tend to lean more towards marine specimen, but this paper might be of help?

 

Proboscidean Ivory.pdf

[Shellseeker]

GREAT photos of adult Rynchotherium tusks !!! Thank you, Ken.  It is not easy to get these beauties in color.
 

Quote

 

Selected tusks and tusk fragments of Cuvieronius or Rhynchotherium (A, C, D) or Cuvieronius hyodon (B, E) from Florida. A, UF 65641 from the Bone Valley Formation (no specific locality). B, UF 88008 from the Leisey Shell Pits. C, UF 19383 from the Bone Valley Formation (Mulberry Phosphate Mine). D, UF 6076, juvenile tusk from the Acline Shell Pit. E, UF 17067, juvenile tusk from the Crystal River Power Plant.

Source publication

 

[digit]

10 minutes ago, Shellseeker said:

GREAT photos of adult Rynchotherium tusks !!! Thank you, Ken.  It is not easy to get these beauties in color.

They are colorful if you can dig them in-situ at Montbrook.

 

Chilly morning but Tammy and I are off to go volunteer dig for the next 6 hours and freeze our butts off.

 

 

Cheers.

 

-Ken

[Shellseeker]

31 minutes ago, JimTheFossilMan said:

Hello!

This area isn't really my expertise - I tend to lean more towards marine specimen, but this paper might be of help?

Jim

Proboscidean Ivory.pdf

Thanks, Jim

Excellent paper that goes directly to the identification of Gomph Ivory. It is an easy read at 11 pages... Very Helpful.

[IsaacTheFossilMan]

16 minutes ago, Shellseeker said:

Thanks, Jim

Excellent paper that goes directly to the identification of Gomph Ivory. It is an easy read at 11 pages... Very Helpful.

Haha, you're very welcome! Happy to help anyone, that's my motto!

[IsaacTheFossilMan]

Oh also, @Shellseeker, my name's actually Isaac, but IsaacTheFossilMan didn't really work... Any suggestions? 

Currently working off IcthyoIsaac, or just plain ol' IsaacTheFossilMan... Maybe ZackTheFossilMan?

[Shellseeker]

1 hour ago, JimTheFossilMan said:

Oh also, @Shellseeker, my name's actually Isaac, but IsaacTheFossilMan didn't really work... Any suggestions? 

Currently working off IcthyoIsaac, or just plain ol' IsaacTheFossilMan... Maybe ZackTheFossilMan?

I sort of like IsaacTheFossilMan,  I looked up the Fossil Man in your neck of the woods..

http://thefossilman.com/

and I found

Quote

A new species of pterosaur, Vectidraco daisymorrisae, has been announced in the scientific world. It was found in the Lower Cretaceous rocks, about 124 million years old, on the Isle of Wight, UK.
The discoverer, a local schoolgirl called Daisy, is a keen fossil hunter and collector of bones, shells and other natural history items. She was only 5 years old when she made her amazing discovery, now housed in the Natural History Museum in London.

To celebrate the find Martin Simpson, known on the Isle of Wight as the Fossil Man, has written a children's book entitled 'Daisy and the Isle of Wight Dragon', aimed at 7-12 year olds with childish parents. It tells the story of Daisy's find in 2008 up to its publication in 2013, in an easy conversational format and a slightly irreverent style for which Martin has become well known.

I thought you might be Martin, incognito so to speak. I am comfortable with any of your choices, Isaac..  just let me know.   Jack (my actual name is John, but I use Jack )

[IsaacTheFossilMan]

4 minutes ago, Shellseeker said:

I sort of like IsaacTheFossilMan,  I looked up the Fossil Man in your neck of the woods..

http://thefossilman.com/

and I found

I thought you might be Martin, incognito so to speak. I am comfortable with any of your choices, Isaac..  just let me know.   Jack (my actual name is John, but I use Jack )

Oh interesting! I'm not him, although he sounds pretty cool.  Alright, nice to meet you, Jack, I think I'll go with IsaacTheFossil man then! Also, oh dear, my tech skills are becoming obvious, I can't work out for the life of me how to change a display name... 

[JohnJ]

17 minutes ago, IsaacTheFossilMan said:

Oh interesting! I'm not him, although he sounds pretty cool.  Alright, nice to meet you, Jack, I think I'll go with IsaacTheFossil man then! Also, oh dear, my tech skills are becoming obvious, I can't work out for the life of me how to change a display name... 

 

Don't fault your skills...it is an Admin function after your initial registration.