The Rock That Keeps Giving

[Kane]

While spending too much time and money at Princess Auto (Canadian version of Harbor Freight), I had picked up a rotary tool to remove some tool marks from a few prepped pieces, as air abrasion seems to take a bit longer. 

 

Before I set about doing that in earnest, I thought I may as well do another probing exploration of a shale slab from the Widder Formation from Arkona that has been quite kind to me. 

 

This was a piece I had entered in last October's FOTM, but I may as well show the slab's history...

 

The first is how I found it during a trip to Arkona back in October with @Malcolmt, @Shamalama (who got the real winning find of the day with his Eldredgeops iowensis southworthi roller!) and @crinus

[Kane]

So I begin working away at the two I know are in there. Sadly, both of them have some minor damage. The upper left one is missing a bit of cephalon shell and a bit of eye. The bottom right one has some missing pygidial spikes. Second picture shows a bit more prep and photo colour enhancement to bring out detail.

 

[Kane]

While probing around, I was greeted by trilobite number three. Unfortunately, that end of the rock broke off. With no proper glue on hand, I desperately used wood glue. It's still holding. This one is far more damaged than the other two, missing flakey shell parts of pleura and glabella. 

 

[Kane]

More exploring, and a pyritized nautiloid appears. Another wee bit of bad luck as it lifted right off, so I had to glue it back down.

 

So this is where I pretty much left it until I could get my hands on something to smooth out those ugly, gouged tool marks.

 

[Kane]

So before I got to remove tool marks, I decided to probe a bit more just in case. I'm glad I did! What started under the microscope as 0.25 mm exposure of a genal spine was met on the opposite side as well. As I cleared more away with a needle, a horseshoe shape started emerging. 

 

At first I thought it was just another fragment. I was digging pretty deep between the spines at this point and was about to give up. But I noticed it was continuing deeper... and deeper... until I hit bottom. Or, should I say, upside down!

 

It was now clear to me that I was working on the ventral side of this trilobite. Oh my. I have never worked from the ventral before, so I was understandably nervous. But, easy does it, I was able to clear more and more. Those who have worked with Greenops from Arkona know how delicate and flaky these can be -- but imagine working from underneath!

 

This is not a negative / impression, but a ventral side Greenops, very likely complete. I had to stabilize one of the genal spines with crazy glue as it flaked off (and it took about 10 minutes with a needle to carefully put it back in place - very challenging for big clumsy fingers like mine!).  

 

 

 

[Kane]

So here are two close-ups of the ventral-sided bug.

 

If you can make it out in the photo, there is a mostly complete hypostome there (I think?).

 

The problem I'm facing now is that I can't risk prepping it too much further. The other complete trilobite does not sit directly on top of this one, and so there is about a few millimetres of matrix between the two. To go further might undercut and break the top trilobite.  

 

...And there could be more if I probe a bit more. Four bugs on one rock is not too shabby at all for Arkona! Not only are there other spaces on this side of the rock, but I also have the option to explore the other side, thin layer by thin layer.

 

At this point, I think I might have to commit this to an expert for further preparation. I just know fiddling around with this for much longer is going to increase the risk of a heartbreaking mistake.

[Ptychodus04]

Nice job @Kane. I think you can go a bit closer to the other trilobite. Consider switching to a scalpel and shaving the shale away under the microscope. I know it’s nerve wracking but if you go slowly and don’t try to take more than the thinnest layer off at a time, you can get pretty close. 

[Malcolmt]

Thats a pretty neat slab you found... we need the snow to go away so we can get back to that bench

[Kane]

2 hours ago, Malcolmt said:

Thats a pretty neat slab you found... we need the snow to go away so we can get back to that bench

Absolutely. And not even all the snow... just a good enough thaw. That slope faces south and mostly full sun so it may be clear even now. This time we have to bring back chunks/slabs from those 6 inch layers to inspect at home!

[Herb]

very nice slab and prep.

[Darktooth]

Good job so far @Kane! Looking forward to seeing it finished. Its a nice piece especially because of the muliple trilos.

[cheney416]

What a nice bugs!

[ynot]

Nice piece Kane!

[Kane]

Thanks everyone.  

 

The only update on this one has been a bit of smoothing, and removing the nautiloid area (glued on, it looks pretty crappy), and getting a bit closer to the other trilo as per Kris' suggestion.  

[JohnBrewer]

Great work Kane!

[Ptychodus04]

9 hours ago, Kane said:

Thanks everyone.  

 

The only update on this one has been a bit of smoothing, and removing the nautiloid area (glued on, it looks pretty crappy), and getting a bit closer to the other trilo as per Kris' suggestion.  

 

Can't wait to see the final results.

[RJB]

Turned out to be a busy rock kane.  I too am lookiing forward to the rock cleanup. 

 

RB