Another return to the Conasauga: The Shale Slabs That Keep On Giving, and a Predicament

[MeargleSchmeargl]

From the very moment we wrapped up at that Conasauga Formation fossil hunt at the spot I'd never heard of before, I was itching to get back there. I guess that's what going for years without hunting half-billion year old bugs does to you. Well, this past Sunday I had my opportunity to get another bug hunt in.

 

It's a good thing I brought my water boots with me, because the spot was quite a bit wetter than the previous time I had come, with some really large puddles at the foot of the hillside I'd get to work in.

 

 

After a good while of splitting, I had myself yet another selection of Conasauga trilos

 

 

Of the specimens I collected this time around, I picked up some really interesting and precarious pieces, most notably this one:

 

 

If this was all there was to this Aphelaspis plate then it'd be a really nice find, but it wouldn't have controlled my attention in quite the way it would have if it didn't also have this:

 

 

Apparently when this piece split, it split into 3 pieces, not 2, with the 3rd piece actually being the exoskeleton of the larger individual in the split. How it hasn't broken/crumbled into a million pieces by now is beyond me especially considering how thin it is, though I'm definitely not sure how I want to approach it as a result. I'd love to be able to bring out the rest of the detail in it, but with how fragile I know these exoskeletons to be, I'm not even sure it's possible to do much of anything, at least not with what I have on me.

 

It goes even further too, as on the opposite sides of each of the main 2 pieces, there's another 2 trilobite individuals, one on each plate!

 

 

The split that keeps on giving, that's how it tends to be with this Conasauga material, even when you're splitting at home! With that collective piece, I think I'll nickname it "Frankenbug". Will definitely be open to ideas on how to approach it!

 

As for the rest of my finds, they may not be quite as remarkable as the piece above, but as per usual you get all your Conasauga Cambrian goodness!

 

 

[Kane]

Great finds. 

As to the predicament involving prep, you know the limonite preservation makes these excruciatingly flakey. If it were me, I wouldn't even try to do a top down prep. With the Conasauga, WYSIWYG. 

 

Maybe Kris @Ptychodus04 might have a better suggestion.

[historianmichael]

I was able to prep a trilobite I found at Tibbs using an X-acto blade to slowly carve away at the block and stabilizing the bug as I went.

[Nimravis]

Nice finds- congrats.

[EMP]

Just make sure to watch out for the wildlife. I came across a black widow resting under one of the pieces of shale XD

[FossilNerd]

Very cool finds. Congrats on the successful hunt! 

[FranzBernhard]

Very nice Trilos, thanks for sharing!

And that outcrop situation is something I know .

Franz Bernhard

[Ptychodus04]

Thanks for the tag @Kane

 

I don’t have any experience prepping these particular trilobites but brittle and flaky are something I’ve dealt with. You can do a top down prep if you go really slow and stabilize often. The trick is having the right equipment to do it. How hard is the matrix? Does it tend to pop clean or be sticky?

 

Hand prep or a very small scribe and lots of Paraloid are a requirement. 

 

I’ve successfully glued brittle negatives together for a prep. You need the thinnest cyanoacrylate you can find and some good clamps. There’s always a chance of ruining the piece but it is possible. Get the underside of the specimen and the opposing matrix completely clean, then coat the specimen with glue. Align the pieces and clamp in place with as much pressure as possible without breaking the rock. For uneven pieces, I use a couple of pine boards on either side to provide a flat clamping surface. You want to use 3 clamps to get the best fit and the boards help spread out the pressure more evenly.