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KatzFeldkurat

Preparing Hauterivian & Barremian Heteromorphs

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KatzFeldkurat

Greetings!

I mentioned in another topic, that I will post some of my heteromorph findings and prepwork.

The locality is in Hungary, and is an abandoned quarry that produced cement for the local factory. It is rich in fossils, but it was a big underwater slope, and because of this the fossils only found in shallow beds, between redeposited layers of "nothing" and always in condensed form, and the bigger pieces fossilized mainly in fragments.

 

Another problem is, that the compressed marls contains only stone molds, sometimes with slick&slides on them, and the matrix and fossil is hard to distinguish

There are some pieces that have the imprints of spines.

 

 

 

Here is one that is a big question for me, because the spine is visible, (at least at 1 section that broke out with some luck) but it is only a thin imprint in the stone, and I really like to have some opinions, what to do with it...

 

I began prepping, but if i only touch the stone with the vibrotool, I see nothing what I do onward, because the fine dust completely obscure the spine, so I could work as I imagine they should be, and I fear that I will destroy it (and the further ones) completely, and I am uncertain to try to fake them from the matrix (But it is already nearly the same) so this is one option.

 

Another problem is that I need to remove a lot of matrix, and I have bitter expectations what will happen with the underlying spines...

 

So there is a second option to do nothing with it, but I like more to have a good prepared spiny Crioceratites in my collection, so I will try anyway :)

 

The first spine from the living chamber is currently "faked" because I do not found the spine imprint yet. The second spine is original (as the stone broke off of it)

(the other fossil is an Orbitolina, but I am not shure)

12.thumb.jpg.007f7c76a9057d24adf11bc9c3f70d18.jpg

 

 

 

The sandy marls are soft and the stone molds that have a thin calcite shells are sometimes found in calcite concretions, the calcite coating is very thin and always damaged. So preparing the material is a challenge. 

Sometimes the spines are preserved, but always broke off. You will see on the pictures below, that the pieces are extremly fragile. Maybe there is a way to preserve, the spines or put them back while preparing?

 

Here is a remains of a spiny one:

15.thumb.jpg.1c4428dd330c1da9a2c608064aa5f8b1.jpg

 

 

 

Here is some finished or nearly finished pieces:

 

From the softer sandy marls:

Freshly found Crioceratites (nolani?):

1.thumb.jpg.a647e367038a97fa32044e3297796255.jpg

2.thumb.jpg.db23d4ec4f834a4a6862403cf2bb9516.jpg

 

Gluing together the pieces:

2b.thumb.jpg.26c19a0021daa658cfe4dd1e931d72be.jpg

 

Restoring the missing part with magic sculpt, and coloring it with powdered stone to imitate the stone molds thin calcite coating. (the color was really hard to match, and I am not satisfied with it, but I done my best with it)

3.thumb.jpg.bdbe8f3a43f6148c282f164f92633cd6.jpg

 

The complete piece, prepared:

4.thumb.jpg.1276552dd2c091d159940fb15444d2ba.jpg

 

 

 

 

Here is some pieces from the condensed marls:

 

Freshly found Crioceratites (duvali?):

7.thumb.jpg.6431b6c66887fd60bdf4b81e7d423d43.jpg

 

Gluing together the pieces:

8.thumb.jpg.ab472007a42112ef867d554b4e90ab53.jpg

 

Restoring the missing parts with magic sculpt, and stone chips from the matrix, and coloring it with powdered matrix

9.thumb.jpg.b8de68635599c8344c3579658ca23cde.jpg

 

There are acrylic lacquer applied, so the fossil is better distinguished from the matrix

9b.thumb.jpg.823dc347c1169c2e2887faf3773f38a3.jpg

 

The complete prepwork:

9c.thumb.jpg.6fde8bd439ff536b9c0a1c56037ad746.jpg

 

Here is another heteromorph, Anahamulina (acuaria?):

10.thumb.jpg.62904aab7f79c9fa51840e5f2dc98a73.jpg

 

 

After prepping out of stone: (need further work)

590c48b33721f_11Anahamulinaacuaria.thumb.jpg.853a50fd5de3d7629ae284395fedb893.jpg

 

 

With kind regards

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Fossildude19

Very nice work! :) 

Thank you for posting your process. 

Regards, 

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Ptychodus04

Beautiful ammonites. I would attempt to prep the spines going slowly and stopping to remove the dust often. You may consider waiting to prep the spines until you can acquire a compressor and pneumatic scribe. This will remove the dust for you as you work.

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JohnBrewer

Nice ammos and nice prep!

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goatinformationist

A good prep job all around.  Congrats.

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Ludwigia

Good advice from Kris. A compressed air pistol would help if you happen to have one. Nice work anyway.

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KatzFeldkurat

Thanks for the encouragement! :)

Sadly I do not have an air scribe, and currently is not an option for me (I live in an apartment)

 

So after studying the piece for days, I began working on the spines so that when the dust became obscure, I washed the piece, let it dry, and worked further. It taught me patience at least, because the process was veeeery slow.

 

In the end I got 3 spines that are original, but I did not find the other preserved, (or missed, despite the slow process)

 

Other thing that I found, that from the red arrow, the spines turn into little knobs, and there is no transition happening from spines to smaller ones, there are spines, and after that there are little knobs. I do not know that if its a fossilizing phenomenon or ontogeny, but I saw a lot of specimen prepared with spines all around... :mellow: I hope some experts may have answers for this!

 

The red marks are the original spines/knobs, the others are "faked" where I saw something that indicated they should be there, the engraver is not the best tool for sculpting, so the knobs turned out to look like spines, but they are not :D

 

20170505_201339bc.thumb.jpg.a0eca1b0cfc21144674e70d1ae7991d0.jpg

 

 

I applied acrylic lacquer to better highlight the fossil from the matrix.

(I am little dissatisfied with the broken part, I imagine the piece having all the spines:drool:)

 

So the completed piece:

20170505_200642.thumb.jpg.ca6ef3ab2e439faee3e577776caea82a.jpg

 

20170505_200814.thumb.jpg.3485e86741404d8cca37884824503208.jpg

 

With kind regards

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Ludwigia

Nice job! The phenomenom with the spines is normal. I've experienced that again and again on spined jurassic ones that some spines are preserved to the end and others not. They have a tendency to break off at those "knobs", which I believe are growth layers.

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RJB

Wow!  Looks to be some real tuff prep jobs.   Id say you are doing some really wonderful prep.  Nice specimens.

 

RB

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KatzFeldkurat
2 hours ago, RJB said:

Wow!  Looks to be some real tuff prep jobs.   Id say you are doing some really wonderful prep.  Nice specimens.

 

RB

Thank you! :)

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Ptychodus04

Well done. I'm not opposed to "faking" spines that appear to have been there originally. That's legitimate restoration. Complete fabrication is another thing all together. What you have done is perfectly acceptable and helps the viewer understand the animal in a better way.

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