Cleaning a fish

[Fishkeeper]

I got an unprepared fish fossil from my grandparents as an early Xmas present, and I've been working on cleaning it up. 

This is what I have after a few hours' work. I've been using the dental scraper pictured, mostly just trying to find the general outlines of the body so I can figure out what species this might be. 

Thing is, I'm a bit confused. The area above the cleaned area to the left is where the head is supposed to be, and you can see raised areas that seem to indicate the structure of a skull, but I'm finding what looks like skin way past that. I also don't seem to have any ribs yet. What's going on? Could the skin somehow have come loose and been moved? 

[snolly50]

Yes, you can certainly have "parts" moved around, if a critter partially decays/abdomen ruptures. You have some verts exposed. I always start there and work out to the margin. If the critter is indeed disarticulated, this can still be a little confusing; but it's the most systematic way I know of approaching the prep. Good luck, have fun.

 

I looked at your photo again and the verts seem small compared to the area of "fish" exposed. That suggests to me that the specimen is indeed somewhat in disarray. That is, there is more area showing than a fish with verts that size should  provide. That doesn't mean it will not be a fun project with a worthy outcome.   

[Fishkeeper]

I did move outward from the vertebrae, trying to move towards the head and find the outline of the skull. I thought I could locate the skull outline and use that to ID the fish, figure out what shape it is, but it doesn't seem to be fish-shaped any more.

Wonder where the ribs are? 

I'm hoping the skull is at least mostly intact, but, yeah, that skin is off in a weird place. 

[RJB]

From the picture it does seem to have problems?   If you shine light from an angle you should be able to see the fish.  If everything is in place that is.  Here is an example of shining light on a fish slab to show the fish.  That fish of yours is close enough to the cerface that it show itself.    Dont know if this helps or not? 

 

RB

[Fishkeeper]

I can see the spine, and what appears to be the rough outline of a skull, but nothing else. I still haven't found any ribs

or fins, and the skin extends far to the sides in either direction. How can one fish worth of skin stretch this far?

Also, how does one sharpen a dental scraper?

[RJB]

Back when I used to prep fish by hand, I used sharpend chansaw files.  You can use a wet stone with honing oil or a diamond file to resharpen. 

 

RB

[Ptychodus04]

18 hours ago, Fishkeeper said:

I can see the spine, and what appears to be the rough outline of a skull, but nothing else. I still haven't found any ribs

or fins, and the skin extends far to the sides in either direction. How can one fish worth of skin stretch this far?

Also, how does one sharpen a dental scraper?

 

I sharpen my stuff with a fine metal grinding belt on my bench sander (This is where knife making pays off on preparation stuff!)

 

I think you are uncovering a large carbon stain. Your fish probably fully rotted and oozed its guts all over the place, leaving that nice greasy black stain in the rock. Or, you have not uncovered the fish yet and it is still deeper in the matrix. There are dark carbon rich layers in the GRF and you may be chasing one of these with the body of your fish concealed beneath.

[ynot]

3 hours ago, Ptychodus04 said:

There are dark carbon rich layers in the GRF and you may be chasing one of these with the body of your fish concealed beneath.

How could He determine if the fish is further in? Dig a test hole?

[RJB]

To be quite honest, I would have thrown this away.  I dont mean to sound mean, but this one has some serious problems.  sorry. 

 

RB

[Ptychodus04]

2 hours ago, ynot said:

How could He determine if the fish is further in? Dig a test hole?

 

Start at the vertebrae and work from the middle of the centrum ventrally, taking the matrix down a layer at a time. You should find some ribs there.

[Sagebrush Steve]

3 hours ago, RJB said:

To be quite honest, I would have thrown this away.  I dont mean to sound mean, but this one has some serious problems.  sorry. 

 

RB

Anyone have a better specimen needing to be prepped they could send her as an extra Christmas present?  Would be a nice way to encourage a budding paleontologist. Unfortunately I don’t, I need to get back out to the Green River this year and replenish my supply.

[RJB]

8 hours ago, Sagebrush Steve said:

Anyone have a better specimen needing to be prepped they could send her as an extra Christmas present?  Would be a nice way to encourage a budding paleontologist. Unfortunately I don’t, I need to get back out to the Green River this year and replenish my supply.

Great Idea Sagebrush.  I would, but dont have any split fish material. 

 

RB

[Fishkeeper]

This is what I have after 5 hours of prep, and I don't think I'm going to continue. I'm gonna keep this, it is interesting from a scientific standpoint. I'm not going to work on it any more right now, though, there's nothing else to uncover. A few scattered bits of skull, maybe, but nothing worth the time and tired fingers. When I get new tools for cleaning fossils, I'll use this as a practice piece. That covered vertebral section could be good practice with new tools, and there look to be a couple of copralites I could try and uncover intact. 

It definitely looks like it decayed for awhile before fossilizing. This is what a fish looks like when it rots and isn't torn apart by larger scavengers- the fins and ribs go missing, soft parts scatter, and the skull falls apart. The tail is still covered here, but I doubt any rays are attached, I couldn't even find the other fins. 

There definitely aren't any ribs still buried. The vertebrae are raised out of the matrix enough that, if there were any ribs, I would have uncovered them by now. The darkness is definitely fossilized, it feels different from the rest of the matrix and is definitely harder. I guess that's what fossilized decay gunk looks like. 

Kind of disappointing not to get a mostly intact skeleton, but oh well, that's the risk you take with mystery fossils. Plus, this is still interesting. I can show it to people who are interested in fossils for more than the aesthetic value as an example of what happens if a smaller organism decays before fossilizing. 

[Ptychodus04]

From the photo, it looks like you have barely uncovered portions of the vertebrae. I’ve prepped a lot of fish and this one doesn’t look like you went deep enough to me. It’s hard to say from only photos though. Always better to put it away for a bit and come back later 

[Fishkeeper]

Gave it one last try, went at the area right below the spine and just behind the head. Figured I'd either find ribs or go right through the stain, ended up going through the stain to the matrix underneath. Definitely no ribs. 

The vertebrae are exposed more than it looks in the pic. I compared this to a couple of professionally prepped fossils I have from the same source, and the backbone on this one is exposed as much as, if not more than, the others.

[RJB]

@Fishkeeper  Ive been thinkin about this and went ahead and went through some of my fish slab material.  Found this if youd like it.  Send me a PM and I will send it to you for $7 shipping.  No charge for the fish.  This is a 7 inch diplomystus.  Harder rock than youve been working with, but it can be done with the 'pick and blow' meathod with a sharp point.  Just takes some time.  Easy peezy.   Oh, a piece needs to be glue back on and you can glue the whole slab onto a piece of fiber board and shape that into an oval, do the prep work and you will have a really nice fish.

 

RB

[Sagebrush Steve]

15 minutes ago, RJB said:

@Fishkeeper  Ive been thinkin about this and went ahead and went through some of my fish slab material.  Found this if youd like it.  Send me a PM and I will send it to you for $7 shipping.  No charge for the fish.  This is a 7 inch diplomystus.  Harder rock than youve been working with, but it can be done with the 'pick and blow' meathod with a sharp point.  Just takes some time.  Easy peezy.   Oh, a piece needs to be glue back on and you can glue the whole slab onto a piece of fiber board and shape that into an oval, do the prep work and you will have a really nice fish.

 

RB

Nice offer, @RJB!  @Fishkeeper, I hope you will be able to take him up on it.  And keep us posted as you prep it.

[Pagurus]

1 hour ago, RJB said:

went through some of my fish slab material.  Found this if youd like it.

 

What a generous offer this is! It's disappointing to come up empty-handed after spending five hours prepping, though it's always a bit of a gamble I'm sure, and it's always a learning experience anyway.

[minnbuckeye]

Nice gesture!!! I bet this represents a taste of your inner  personality, to be so giving, and not just the Xmas spirit that so many of us exhibit for maybe a month at the most.

 

Happy holidays,

Mike

[RJB]

1 hour ago, Pagurus said:

What a generous offer this is! It's disappointing to come up empty-handed after spending five hours prepping, though it's always a bit of a gamble I'm sure, and it's always a learning experience anyway.

I just felt so bad for her.

 

21 minutes ago, minnbuckeye said:

Nice gesture!!! I bet this represents a taste of your inner  personality, to be so giving, and not just the Xmas spirit that so many of us exhibit for maybe a month at the most.

yeah, thanks, I am a purty nice guy, but lets see if she takes me up on this offer. I hope so.  Ive got so many fish I dont mind doing this. 

 

RB

[Ptychodus04]

1 hour ago, Pagurus said:

 

What a generous offer this is! It's disappointing to come up empty-handed after spending five hours prepping, though it's always a bit of a gamble I'm sure, and it's always a learning experience anyway.

 

I can attest to the disappointment of time spent on junk. I’ve spent many an hour on fossils that turned out to be total snarge!

 

Also, @RJB is a very generous and kind person. I’ve witnessed that several times.

[Fishkeeper]

I am absolutely interested, thank you so much! PM sent.

I'll be sure to make another thread of the progress on that one, it looks impressive already.

[Ptychodus04]

2 hours ago, Fishkeeper said:

I am absolutely interested, thank you so much! PM sent.

I'll be sure to make another thread of the progress on that one, it looks impressive already.

 

Get ready to spend about 30 hours on it! That fish is in some hard rock but guaranteed to be a good one.