Jump to content
wrfisherman

NSR shell -

Recommended Posts

wrfisherman

Hello all!  Happy Georgious December!  (almost 80 today!)

Anyway, I got a rare day away the day after Thanksgiving and took my oldest back to the Ladonia Fossil Park on the North Sulphur River.  We normally hunt upstream of the 2990 bridge, but thought we'd slow the pace down and get into the gravel.  We knew we hadn't had any recent rains to clear out all the shale clasts that have filled the river bottom for the last several months.  

While much of the "Mush" has either dried and crumbled, or washed away, there is still a lot of it covering the ground.  We found very few actual gravel deposits around the park except where exposed by hundreds of boot prints.


We did find a few various shark teeth, a broken mosasaur tooth fragment, some Mastodon tooth enamel, - the normal finds around there.

We noticed a family leaving and they had been digging around the bank where the gray clay/silt turns to a tan color - well above the Red Phosphate layer.   One piece they had dislodged looked interesting and as we moved it, it broke open to reveal the fossil below.  I've found fragments of this before upstream of the 2990 bridge, but never this much of it.  I got a couple of pics right away, since this material starts to dry, shrink, and crack pretty quickly.  We then wrapped each in plastic and soft cotton to transport back.  However, the side of the fossil with the shell turned to dust and disintegrated.  The shell is paper thin (like some of the larger white baculite shells) and is only the surface shown (meaning it doesn't curve around in the matrix and finish on another side.  It's just this surface.  One side has raised bumps and the other pentagonal depressions in the cast.  First glance is the shape of a paddle (like turtle), but a) it's a shell coating - and b.) it has no bones.  It's purely shell.

It doesn't extend further into the matrix block.

 

I'm  good on most things Sulphur River, but this has been a mystery every time I've found it.  Thoughts?

Texas, North Sulphur River

Ladonia Fossil Park

Ozan Formation

20171124_144603A.jpg

20171124_144642B.thumb.jpg.2c332dc047963487d2f6674193c34b3f.jpg20171125_183258A.thumb.jpg.99427bb8a9a4916373bb4cbef5bc090a.jpg

Share this post


Link to post
Share on other sites
JarrodB

I cant' help ID the impression but good to see back out and about buddy. Hope to see you around one day. 

Share this post


Link to post
Share on other sites
wrfisherman

Thanks Jarrod.  Been so super busy with work, haven't been able to get out in a long time.  A couple of Post Oak Creek short trips so lots of sharks, but that's about it.  Talk to you soon,

M

 

Share this post


Link to post
Share on other sites
Uncle Siphuncle

Could be a chunk of Placenticeras.  I’ve seen this pattern on living chambers of large ammos.

Share this post


Link to post
Share on other sites
PFOOLEY

I remember reading somewhere about bryozoans living on the shell, inside of the living chamber, of ammonites...a sort of symbiotic relationship. 

 

I wonder if this is the impression of such a colony?

 

@wrfisherman, could we see a better photo of the counterpart?

Share this post


Link to post
Share on other sites
wrfisherman

Thanks for the thoughts.  On Paleodictyon - it certainly has that shape, but with Paleod it's normally the tubes that form the shapes and this is smooth with no differentiation between the "cells" - just moves from one to the next.  I'll shoot some closeups of what still remains tomorrow.  Since one edge is fairly sharp like that of the Ammonite Spirals I had wondered that, but there is no evidence of any sutures or any ammonite structure.  I find them frequently and this has none of the characteristics except for that very fragile outer shell.  I'll post the closer-ups ASAP.  Here are a couple from just the phone camera.  You can see that the patterning is cast on both sides in the matrix, so no other patterning within the shell.

20171205_131140.jpg

Share this post


Link to post
Share on other sites
PFOOLEY

From that photo, it looks like the shell itself takes that shape...that is very cool.

Share this post


Link to post
Share on other sites
abyssunder
On 12/5/2017 at 5:57 PM, Uncle Siphuncle said:

Could be a chunk of Placenticeras.  I’ve seen this pattern on living chambers of large ammos.

Do you have a picture of one specimen showing this feature?

On 12/5/2017 at 7:05 PM, PFOOLEY said:

I remember reading somewhere about bryozoans living on the shell, inside of the living chamber, of ammonites...a sort of symbiotic relationship. 

I'm interested to see a bryozoan with this mostly hexagonal network, because I've never seen before something like this. If you remember where you see that, please post here.

 

Share this post


Link to post
Share on other sites
abyssunder
On 12/5/2017 at 6:44 AM, wrfisherman said:

However, the side of the fossil with the shell turned to dust and disintegrated.  The shell is paper thin (like some of the larger white baculite shells) and is only the surface shown (meaning it doesn't curve around in the matrix and finish on another side.  It's just this surface.  One side has raised bumps and the other pentagonal depressions in the cast. 

 

 

Are you sure it is an ammonite fragment?

Share this post


Link to post
Share on other sites
westcoast

Looks like the trace fossil paleodictyon

Share this post


Link to post
Share on other sites
michaelzzz

It does look like impression of ammonites. Here is one I found last month at NSR, don't know what kind though. 

IMG_20171112_1403307_rewind_copy.jpg

Share this post


Link to post
Share on other sites
PFOOLEY
14 minutes ago, michaelzzz said:

It does look like impression of ammonites. Here is one I found last month at NSR, don't know what kind though. 

IMG_20171112_1403307_rewind_copy.jpg

Nice addition to this thread. :fistbump:

 

This is not the same...

...but similar ( and still a mystery ).

Share this post


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.

×