Trachyscaphites springer prep question

[KimTexan]

I found this ammonite on Saturday. It is the best Trachyscaphites springer I have ever found. I think it is a T. springer. I assume the other ones I have are males and maybe this one is a female. I don't know much about sexual dimorphism in this genus, but it does exist. When they say there is dimorphism is the female is bigger?  It is so very different from any of the others I have. I know there is another species of Trachyscaphites in the NSR, but I don't know what it looks like.

I really like this one though. It is free standing too! Bonus. It has some damage on the dorsal venter and the aperture. It also had some pyrite on the umbilicus area (I can’t really see an overt umbilicus since it is so involuted).  My prep work is still very crude. There is so much I need to learn. I just keep at it and learn by trial and error though. 

 

I don’t have pneumatic tools.

Here it is. See the white film on the right half? The white on the left half is nacre, but some of it has the film on it too. This is from the red zone of the Ozan formation, Cretaceous. 

I doubt it matters, but I am wondering if the film layer is pyrite in nature or gypsum or something else. I have specimens from the Britton formation of the Eagle Ford group, which have a gypsum film on them and this looks a bit little that. But that isn't my main question. It is just a curiosity.

 

 

This is the other side. You can see some pyrite at the bottom left along the umbilicus grove. I have a number of these, but this is the first where I can actually see suture lines mostly at 11 to 12 o'clock down the midline and on the right.

 

I am going to tag @Ptychodus04 and @RJB on this. I don't know if Ron is familiar with fossils of this matrial and matrix, but I imagine he is. I am pretty sure Kris is.

 

Questions

The film issue

1. Do you think I should attempt to remove the film?

I think I should. See the tubercle by my thumb in pic 2? There was a tiny fleck of white showing so I chipped away at the red clay and revealed more nacre under it. So I believe there is still nacre under some of it on the left

2. What is the best way to go about removing it?

I was thinking of using sandpaper, but I don't have much experience using sandpaper on fossils. I have a range of grit up to 3000 (or is it down to since the grit is smaller and finer?)

 

The nose issue

I am calling it the nose since it looks like a little nose. It seems to be the first part of the first visible whorl.

3. Any advice as to what to do with this part. I am not sure what to do with it. At times I prep haphazardly and then I think I have damaged it and I get paralysis of analysis and that is where I am on the nose.  I have removed some matrix from the top, left and right. I think I might have gone down into the nose on the right side some. It is hard to tell where the matrix ends and fossil begins.

 

These are other views of the nose. The lines on the nose are from me scraping away, thinking I was on top of ribs. I am not sure if there are ribs there yet. Like I said my prep skills are pretty crude still.

 

The other side of it. I still have some matrix to removed on the side there. I think part of it is chipped away, but I am not totally sure how it is supposed to look. Maybe it got crushed. It just looks odd to me. I have several other of this species, but I think they may all be males or something. They are more open, the whorl does not cover the umbilicus and they are much flatter and smaller. 

 

The pyrite issue.

I know I have asked these types of questions before about prep so sorry for the repeat.

 

4. What is the best way to address the pyrite to keep it from coming back? I have scraped most of it off already. I have heard people say to soak it in Iron Out and I have that. But I am concerned it may hurt the fossil. I guess I could experiment on other concretions I have that look like the same, but are rock and not fossil.

 

5. What should I do as far as long term preservation to slow the progress of pyrite disease? I think someone recommended Butvar. I looked into buying it, but I got sidetracked by trying to figure out which was best. Then couldn't find what was best and kind of forgot about buying again.

 

6. What is the best Butvar or product to use for sealing it?

 

I looked at buying some on different sites. Paying so much for shipping irks me. I am spoiled with Amazon Prime and just don't think about shipping costs.

 

I have a buddy who works at Eastman. I asked him if they had a store where individuals could purchase products like Butvar 76. He said no, but he would see if he could go ask for a sample

The museum supply site. It has Butvar-80 for $34 for 1 kg and $15.53 for shipping. I don’t need 1 kg.

Talas has Butvar-76 500 g for $17.50, but then is charging $14.64 for shipping!

I have seen people reference McGean-15 or Vinac and they seemed to prefer it over Butvar. 

7. Can anyone tell me the molecular weight of the Vinac or what grade of polyvinyl acetate Vinac is? I think my buddy could come up with that for me more easily since I think he manages production of a form of it.

 

I found something called Vinapas. I have not looked at the shipping on this site. Here:

http://www.conservationresources.com/Main/section_37/section37_08.htm

PVA Resin Solid Vinapas     This consolidant is a polyvinyl acetate solid suspended in granular form, with a molecular weight averaging 51,000 and a melting point of 50 C. It is used as a consolidantfor porous, dry, non-metal objects-particularly those found in digs. This is typically applied in concentrations of 20-25% I.M.S. with a soft brush. It may also be used as an isolating varnish and thermoplastic adhesive.

Item #	Description	Price
SY01	Vinapas, 1 kg.	$22.00

[Ptychodus04]

I’m going to need some emergency rations to read all the way through this post I think. 

 

First, I would say this is most likely a T. springer as they are the most common. Typically dimorphism in ammonites is interpreted as large/robust = female and small/gracile = male.

 

On the prep, I would try to pick away what you can of the thin matrix coating with dental pics. The preserved shell material is very delicate on these specimens.

 

The Vinapas pic that you posted says it is a PVA solid in suspension. You don’t want to put this on a fossil. Suspensions are a nightmare a few decades down the road and they are not easily reversed.

 

If you plan to get into prep, I would suggest buying a pound of Paraloid and pay the freight. It will last a hobby prepper for years.

[KimTexan]

 

Sorry for the long post.

Thank you for your answers. I have been wondering about the dimorphism thing for a while. I guess all I have found are the males until this one.

 

So no sandpaper your saying not even 3000?

Which paraloid or is there only the Paraloid B-72?

 

It say suspended in granular form. If you don't get granules is it called a powder?

If I can find a dry form of polyvinyl acetate would it be best? If so do you know the molecular weight or any defining characteristic? I am pretty sure my friend manages a part of the plant that makes polyvinyl acetate. They make it by the hundreds of tons. He said he could get me a sample bag.

[Walt]

paraloid_b-72_data.pdf

[Walt]

ADDBVR3978.pdf

[Paciphacops]

You may want to check our favorite auction site. Paraloid b72, $15.95 for 250 grams with free shipping. 

[KimTexan]

3 hours ago, Paciphacops said:

You may want to check our favorite auction site. Paraloid b72, $15.95 for 250 grams with free shipping. 

Thank you so much. I bought some.

[Uncle Siphuncle]

Minor taxonomical correction, I believe it is T. spiniger as opposed to T. springer.

[Ptychodus04]

@KimTexan, I was just messing around about the length of your post. This one is going to be fairly verbose itself. 

 

I don’t use sandpaper for anything other than prepping for a polish. It’s not really useful for general prep work.

 

On the topic of consolidation material, you want to buy only pure dry material. Avoid anything that says suspension or suspended as that means the material is in a solid or semi-solid state mixed with a non-solvent material. The solids don’t make it very far past the surface of what you are consolidating so you wind up with a hard outer layer and no internal protection. Also, suspensions act differently than solutions and tend to be very hard to remove after they have set.

 

A solution of your preferred plastic (Paraloid, Butvar, Polyvinyl Acetate) in a solvent like acetone penetrates deeply and once the solvent evaporates, the plastic is easily removed with the same solvent.

 

There are a couple different formulations of Paraloid but you only want to use B72 for fossil applications. A few years ago, I tested another Paraloid (can’t remember which) and it did not have satisfactory results in my testing. B72 has the benefit of historical use in paleo conservation.

 

Butvar B76 is widely used by museums but my understanding is that it is no longer in production. I may buy 15 pounds of it and that should last a while. I probably use 1/2 a pound a year and I do a lot of prepping.

 

Boring rant about plastics is now over. We now return you to your normally scheduled enjoyable TFF browsing.

[Ptychodus04]

10 hours ago, Uncle Siphuncle said:

Minor taxonomical correction, I believe it is T. spiniger as opposed to T. springer.

Thank you sir, you are correct. 

 

@KimTexan, the other Trachyscaphites species found in the Ozan Formation is T. deniscostatus but they aren’t as common according to Emerson and Akers.

[-AnThOnY-]

On 10/27/2018 at 8:19 AM, Ptychodus04 said:

Thank you sir, you are correct. 

 

@KimTexan, the other Trachyscaphites species found in the Ozan Formation is T. deniscostatus but they aren’t as common according to Emerson and Akers.

 

Old post but do you have a link to the paper that shows any images of T. deniscostatus?

[Ptychodus04]

9 minutes ago, -AnThOnY- said:

 

Old post but do you have a link to the paper that shows any images of T. deniscostatus?

No images. I found a description of it in "Texas Cretaceous Ammonites and Nautiloids" by Emmerson, et. al.