From Butte to Beaut

[Peat Burns]

Thought I'd share a few photos of a tortoise prep I just completed.  This is from the white river group of Chadron, NE (circa 33 mya).   Here is a series of photos from discovery to excavation to restoration and preparation.

 

The discovery:  broken shell (As usual, I forgot to take a true "before photo".  I've already probed a bit here).

 

 

 

After some digging, it was discovered that this individual is upside-down.  Here, the plastron is being revealed.

 

[Peat Burns]

Most of the plastron has now been exposed (now several hours into the dig)

 

[Peat Burns]

Here I begin to trench around the specimen to for a pedestal.  As you can see, the left shoulder area is damaged / blown up.

 

 

 

After several more hours of work, it's time to take a break...

 

 

More work on removing matrix from the back wall so I can start to undercut for the plaster jacket.  Half-eaten sandwich on the ziplock with a nice sprinking of matrix.

 

 

Completion of undercutting.  (I'm securing with field consolidant as I go)

 

 

Here is a view from the side showing the undercut. I DO NOT want the carapace to fall out when I turn this thing over...

 

 

A separator of aluminum foil and duct tape is added to keep the plaster off the fossil.

 

 

Addition of plaster soaked burlap (with apologies to Butter Ball turkeys)

 

 

 

 

 

[Peat Burns]

Whew!  The flip went fine, and no blowouts.  This side was then covered with aluminum foil and plaster for loading in the truck and transport home...

 

 

One last look at the spot where I spent 8 hours excavating the specimen.

 

[Peat Burns]

The carapace with most of the large bits of matrix removed.

 

 

The plastron, also still farm fresh...  Note the damage on the right.  This will be a display specimen, so I will restore this area.

 

After some cleaning and repair work on the carapace.

 

 

After cleaning and repairs on the plastron.

 

 

After sculpting and painting the restored area...  The ruler on the left is about 13 inches long.

 

[Peat Burns]

I still have some minor cosmetic work to do, but here are the primary results of the prep...  Scale is 1 ft.  Carapace on left, plastron on right.

 

 

Here are side, anterior, and posterior views.

 

 

Thanks for looking!

 

 

 

 

[ynot]

Very nice piece! Wonderful preparation on it.

[Peat Burns]

5 minutes ago, ynot said:

Very nice piece! Wonderful preparation on it.

Thanks ynot! (Btw, I accidentally hit the submit button twice, so that's why there is a duplicate post with no content.  I couldn't figure out how to delete it)

[thelivingdead531]

Excellent work! It's a great piece. 

[JohnBrewer]

A fab find and a very educational thread.

[izak_]

Great job! 

[Ludwigia]

Great work on such a delicate subject!

[jpc]

Nice work.  I would have put a top jacket on the top side (Plastron) before excavating quite so much under it, but hey, to each his/her own.  

 

I'm glad you mentioned that it was an 8 hour dig.  Most folks don't realize how time consuming a simple large turtle can be in the White River Fm.  

[FossilDudeCO]

Looks fantastic! Thanks for the step by step!

Congrats on a gorgeous specimen!

[RJB]

  Wow!  Love all the pics!  To see all the process of finding that, getting it out of the ground and all the pics of prep is outstanding!!!  Just a wonderful job you did!  Thanks so much for this post!!! 

 

RB

[Ptychodus04]

Very nice. Great series of photos. I felt like I was there sprinkling matrix on your sandwich when you weren’t looking. 

 

 

[Miocene_Mason]

Nice job! 

[caterpillar]

Very nice job and well illustrated

Thanks for sharing

[Peat Burns]

@thelivingdead531, @JohnBrewer, @Foozil, @Ludwigia, @jpc, @FossilDudeCO, @RJB, @Ptychodus04, @WhodamanHD, @caterpillar, Thanks very much for the kind words! 

[Peat Burns]

I forgot to mention what appears to be rodent ichnofossils on the carapace.  There are perhaps 8 or so of these markings.  I know that some circular marks on turtles that look like bite marks are actually damage from bacterial or viral infections, but these markings look like gnaw marks to me. I haven't looked at them under the scope yet to examine the possible "incisor" marks yet, though.

 

[caterpillar]

If you can make a cast

[RJB]

Rodent damage.  Very interesting. 

 

RB

[Kane]

Late to this, but thanks for documenting the entire process from the field to the prep bench! You did honour and justice to a really neat find with some excellent, patient(!) extraction and restoration. 

[PFOOLEY]

Stellar documentation. 

[Peat Burns]

On 10/28/2017 at 9:22 AM, Kane said:

Late to this, but thanks for documenting the entire process from the field to the prep bench! You did honour and justice to a really neat find with some excellent, patient(!) extraction and restoration. 

 

On 10/28/2017 at 9:48 AM, PFOOLEY said:

Stellar documentation. 

Thanks Kane and PFOOLEY!

 

Kane, I felt I owed some kind of lengthy  contribution to "pay" for my enjoyment of all your Devonian trip reports as well as the many other great posts on here