Jump to content

Priscacara Prep from 18" Layer


Sagebrush Steve

Recommended Posts

As I mentioned in a previous post, when I was at the Tucson Fossil Show I picked up some unprepared slabs of Green River Fish from the 18” layer.  That prompted some of you to say you expected me to post photos as I did the prep work.  I initially rejected that idea because I’m pretty bad at prepping and I didn’t want to post pictures showing how bad I am.  But then I remembered some advice I once got from a manager I reported to early in my career.  After I made an engineering decision that didn’t turn out so well, he told me, “It looks like your fate in life is to serve as the bad example everyone else learns from.”  That cheery sentiment was underscored by this framed inspirational poster he had hanging on his office wall:

 5a8cf67e27f84_SinkingShipPoster.jpg.47fd033df478b7fb590359d04a667da2.jpg

So with that in mind, I decided to go ahead and post photos of my prep work, not to show you how to do it, but rather to give you the bad example everyone else can learn from.

 I picked up a total of four slabs, but the one I will show you in this and subsequent posts is one that was claimed to be a Priscacara species.  Of course you don’t know for sure until you do the prep, but I wouldn’t be surprised if they had done some sort of X-ray before they put the slabs out for sale to make sure they weren’t selling a rare specimen for a dirt-cheap price.  In any event I’ve been happy with the specimen, even if the quality of the prep could be better (this is my first time prepping a specimen from the 18" layer).  I actually started the initial prep while still in my hotel room in Tucson, but I don't have a photo of this fish from there.  Here's a photo of one of the other slabs to give you an idea of what they looked like.  The seller drew a bunch of lines in pencil to show what he thought was the outline of the fish, so that's mostly what you are seeing here. 

 Priscy-1.jpg.9ca25237a76757d0fe4f9f0374d3f25c.jpg

 

It was a lot easier to prep once I got it home.  I only have manual scribes so it is a very slow process.  Here’s a photo of my setup.  I’m convinced I would not be able to do this without the microscope, which I keep at the lowest setting, 6X.  I have 3 probe tips, all purchased from Paleotools when I was at the show.  I also bought two pin vises to go along with the one I already had.  Of the probe tips, one is oval, one is flat like a flat-head screwdriver, and one is a sharp point.  With my technique I have found the oval probe to be the most useful, followed by the flat tip.  I only use the pointy one to do delicate cleanup in tight spots.  To keep the dust from getting all over the place I mostly use the yellow brush to clean it off and save the blower for critical spots.  Even then I don't use it at anywhere near full blast power.  Even so, you can see it's already covered in dust.

 5a8cf710bfcd7_PrepSetup2.thumb.jpg.643e2741c986110499b951b63aed90bd.jpg

 

Here’s how it looks after about 5 hours of prep (I said it was a very slow process!).  The tail looks like it has been blown up, probably due to decomposition before being covered with silt.  The ribs are looking pretty good except for at least one that’s far out of position and pointing in a completely different direction than the rest.  Looks like it has 9 dorsal spine rays, which is consistent with Priscacara serrata.  The areas around the pelvic fin and where the caudal rays branch from the body were prepped by the seller, probably with air abrasion, I assume to help sell the specimen.

 Priscy-2.jpg.4c3c836a109391799f8167437cb20a15.jpg

 

Here it is after about another 3 hours, mostly to expose the anal rays and further clean up the dorsal spines.  It has 3 anal spine rays, further confirming it identification.  You can see my favorite probe tip on the left.  Next up is to start working on the head, which will be more difficult because the matrix covering it is a lot thicker.

Priscy-3.jpg.4d06cc0f375c645941702a063a9ec579.jpg 

 

This fish is definitely from the 18” layer, as the smell of petroleum is pretty strong.  I’m finding I can only work for about half an hour at a time, two or three times a day.  If I work longer, I get nauseous and get a headache that doesn’t go away for a day.  So this is making the prep go even slower.  I did a search on the TFF forum for other threads on prepping Priscacara from the 18” layer and found a good one from back in 2017, in which @Ptychodus04 recommended dampening the matrix to soften it.  I have been doing this and it not only softens the matrix it also keeps down the dust and fumes.  And it adds contrast when I take photos.  Good idea!

 Here’s where I am at now, after about another 5 hours of work.  The head is starting to emerge, but I have to say I can’t identify any of its features when I compare them to the photos from Lance Grande’s book, The Lost World of Fossil Lake.  Not sure what is going on here, I’m open to suggestions.  Meanwhile I will keep plugging away and post occasional updates as I have them.

Priscy-4.jpg.bb198c1e7756077b4f24c3cc1b107ea4.jpg

 

What are these bones?

Priscy-5.jpg.95112bb6f761e1756e43cadf916b6b60.jpg

Link to comment
Share on other sites

Very nice job you are doing.

I have been wondering how these fish are prepped and you are documenting the process very well.

I can't give you any advise but I can sure learn from you.  And not your mistakes. :dinothumb:

Thanks for posting up how you are accomplishing it. I will be looking for more updates.

Link to comment
Share on other sites

@Sagebrush Steve, don’t sell your prep skills short. That fishy is looking really nice so far. Keep it up. 

 

skull bones can be hard because they are often displaced and quite confusing. I don’t bother trying to identify to a species until the prep is done.

Link to comment
Share on other sites

Looking good so far! 

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

Link to comment
Share on other sites

:popcorn:

    Tim    -  VETERAN SHALE SPLITTER

   MOTM.png.61350469b02f439fd4d5d77c2c69da85.png      PaleoPartner.png.30c01982e09b0cc0b7d9d6a7a21f56c6.png.a600039856933851eeea617ca3f2d15f.png     Postmaster1.jpg.900efa599049929531fa81981f028e24.jpg    VFOTM.png.f1b09c78bf88298b009b0da14ef44cf0.png  VFOTM  --- APRIL - 2015  

__________________________________________________
"In every walk with nature one receives far more than he seeks."

John Muir ~ ~ ~ ~   ><))))( *>  About Me      

Link to comment
Share on other sites

Excellent! 18" fish are relatively difficult, as you are discovering. The skull elements are hard to compare with Grande's illustrations because your critter's are disarticulated.

You mentioned x-ray predictions, but the spines of the Priscacara are so robust they usually provide a Dx while obscured by matrix. Dust, I recommend outside (and so does the snollywife). Looks great. My first fish was a large, 18" layer Knightia. Oh, lastly don't wreck your hand with all that repetitive movement. 

Human beings, who are almost unique in having the ability to learn from the experience of others, also are remarkable for their apparent disinclination to do so. - Douglas Adams, Last Chance to See

Link to comment
Share on other sites

Thanks, @Ptychodus04, @snolly50, @RJB, and everyone else for your encouraging words about my prep job.  Every time I watch a little sliver of bone go flying off into space as I am trying to be careful in my prep, I keep thinking, "Darn, Lance Grande @RLG would strangle me if he saw what a hack job I was doing preparing such a fine specimen." :shrug:

 

4 hours ago, Fossildude19 said:

:popcorn:

 

Hey, @Fossildude19, at the rate I'm going you'll need this:

https://www.amazon.com/Bulk-Non-GMO-Yellow-Popcorn-Case/dp/B00TRF1SKU/ref=sr_1_22_s_it?s=grocery&ie=UTF8&qid=1519234538&sr=1-22&keywords=large%2Bpopcorn%2Bkernels&th=1

 

Link to comment
Share on other sites

It looks like you're having fun with that fish, and you're doing a fine prep job too. I appreciate that wall poster. I was asked, many years ago, where I made a left turn in life. That fish of yours has a lot of character. I like fossils with interesting stories like yours. Thanks for sharing it. I look forward to seeing more, but take your time and try to avoid those fumes! 

Start the day with a smile and get it over with.

 

Link to comment
Share on other sites

Great work so far! :)

By the time you've finished, Steve, it will be good enough to eat. 

Yuuuuuuummmmmmmyyyyy fishy! 

Life's Good!

Tortoise Friend.

MOTM.png.61350469b02f439fd4d5d77c2c69da85.png.a47e14d65deb3f8b242019b3a81d8160-1.png.60b8b8c07f6fa194511f8b7cfb7cc190.png

Link to comment
Share on other sites

7 hours ago, Sagebrush Steve said:

I keep thinking, "Darn, Lance Grande @RLG would strangle me if he saw what a hack job I was doing preparing such a fine specimen."

As he tags him:D

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

Link to comment
Share on other sites

1 hour ago, WhodamanHD said:

As he tags him:D

Just want him to know that somebody actually reads his books. :)

Although he hasn’t been online since November so it might be a futile gesture.

Link to comment
Share on other sites

7 minutes ago, Sagebrush Steve said:

Just want him to know that somebody actually reads his books. 

Your not alone, I'm reading it as well. I didn’t know he joined, always good to have some paleontologist on call here.

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

Link to comment
Share on other sites

21 hours ago, RJB said:

 Hey @Sagebrush Steve, being hard on yourself can only make yourself a great prepper!!!   Dont be so hard on yourself.

 

RB

 

That's right. If everybody practices up and becomes excellent preppers, I'll run out of clients really fast! :P

Link to comment
Share on other sites

Another couple of hours in, and I'm concentrating on the head now.  Still lots of matrix in the nooks and crannys, not sure if I could remove it with an air abrasive system (which I don't yet have).  The skull seems somewhat messed up.  I've been able to identify a few of the bones, like the Parasphenoid (the long straight bone under the eye), and maybe the Cleithrum, but I'm not sure what the big boomerang-shaped bone up front is.  Maybe a displaced Preopercle, since I don't otherwise see one?  I've attached a grab of a Priscacara skull from the 1984 edition of Wyoming Geological Survey Bulletin 63 and a generalized diagram from the same paper.  Feel free to try to identify things on your own.  I'll keep working on it and move on to the region behind the skull next.

Priscy-6.jpg.cd508f46a044c75e58c0629e80651caa.jpg

 

Skull closeup:

Priscy-7.jpg.41af024c160b253544c919023e570ee9.jpg

 

From WGS Bulletin 63 (flipped from the original):

5a8f89e48ad1c_PriscacaraBulletin63.thumb.jpg.16649ba3cde00f1a4b652234908e0189.jpg

 

5a8f8a702b86a_PartsofFishSkull.thumb.jpg.0bcf837c681739c918cec31eacce919d.jpgParts of the skull (From Bulletin 63):

 

Link to comment
Share on other sites

9 minutes ago, DevonianDigger said:

Looks great! Keep up the good work! You're inspiring me to dig out my unprepped 18" slab I've had kicking around for over 25 years!

Be sure to post photos when you start prepping it.

Link to comment
Share on other sites

1 minute ago, Sagebrush Steve said:

Be sure to post photos when you start prepping it.

 

I did a rough start when I first got it. I was rather young and it was a gift. I was so excited to start it. Once I got about 3 hours into it, I was less excited... Who'd have thought that later in life I would find myself prepping fossils as a second job! I'll take some photos and I suppose I could give it another go. Haven't done too much manual prep lately, could be a nice change of repetitive motions for a while, lol!

Jay A. Wollin

Lead Fossil Educator - Penn Dixie Fossil Park and Nature Reserve

Hamburg, New York, USA

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...