Been a while since I updated the blog, but winter is a slower time on the fossil front. Compared to last winter, even purchases are down as I either have most of the stuff on offer, it's too expensive, or it's not in pristine condition. But I do have a trilobite coming in a few weeks, and one other I received not long ago. This post will be a potpourri of odds and ends. Lots of stuff coming up...
Pictured here is a wee Acastoides sp. from Morocco. It was cheap and very nicely articulated, so I added it to the trilobite family. I've also had a bit more cash in the PayPal account due to selling some surplus trilobites.
I also managed to spend an afternoon adding to my trilobite sketchbook with these two Russian beauties.
It's a rock! No, not just a rock, but a Russian rock, and a Russian rock containing an asaphid I am currently preparing. Due to the nature of the matrix, and my current tools, this is a 100-200 hour job. I'll create a separate post when it's done.
Hobbling my preparation efforts has been a clogged air hose, likely in the built-in moisture trap for my Paasche AECR. One might think a basic air hose with a 1/4" - 1/16" would be a cinch to replace, but three hours of hardware store visits and plenty of time searching the web says otherwise. I finally got my part and am ready to get to the next critical phase in the prep, which involves swapping between scribing and abrading due to the stickiness of the matrix.
And that wasn't the whole of my prep equipment frustrations, either. I had just been talking with my friend Kevin, saying that I've gone over a year without needing a filter on my lines. Well, no sooner than I said that, the scribe starts acting more like a garden hose. So a trip to Princess Auto to fix that, and to locate a replacement hose (see above). I was also having serious air leak issues, and teflon tape for my big clumsy fingers usually results in my exhausting all the blue words I know, so I've gone for thread sealant instead. The filter/desiccant has already made for a much drier scribing experience. Nothing can be more frustrating than doing precision work under the scope while maintaining critical control of the tool than when it sprays water all over the fossil, turning scribing dust into cakey, opaque mud. And also pictured is a resupply of those handy nitrile gloves.
So when is the first dig of 2019? I'm hoping this weekend, weather and opportunity pending. I've got some other trips planned, too. It will be fantastic to get this season rolling and spend time with my favourite field comrades again as we swing hammers as spring clamours!
On a bit of a tear when it comes to scratching about with the pencil. These are the newest additions. Up to ten trilobite drawings now.
What else can one do that is fossil-related when collecting is not possible and the prep queue is virtually empty? More drawing, of course. Here are the results of a lazy Sunday afternoon (+ Tuesday):
All of these were done using just a standard HB pencil. I wanted to focus on the more "dynamic" trilobite poses as opposed to the straight-on-from-the-top sketch. By drawing these bugs from my collection at different angles and poses, it means relying on more looking at the subject than relying on assumed symmetry. In other words, drawing what one sees, and not what one thinks is there, which is pretty much the standard first lesson of any life drawing class.
Until winter clears, I can foresee doodling up a few more of my bugs. I can't say I mind the practice, and the results generally satisfy me. It isn't preparation, but almost as painstaking.
Snow-free until January 10, and then it clobbered us. More time spent indoors and thinking that it will take a while for this snow accumulation to melt and get the collecting season back into gear. So that leaves prep and postal formation.
This is a return engagement with a bug I started a few months ago. It is a giant for the location (Penn Dixie) that measures over 45 mm from genal to folded over genal. What is not shown in this image is the folded over/under side that took a ridiculous number of hours. I also took the time to level and smooth the matrix -- something I am learning to get better at, and which also takes a lot of time and patience.
A very lovely full prone Scabriscutellum furciferum from Morocco.
The seller was also kind to add an unexpected brachiopod surprise to perk the package.
My 100th trilobite species! Asaphellus fezouataensis from a really nice seller who also threw in a little enrolled phacopid.
Still trying to relearn my old drawing skills that have been neglected for nearly 20 years, a pencil rendering of an Isotelus.
A Greenops widderensis...
And an Eldredgeops rana with all the crush/distortion flaws.
So, for now, that's about it. I'm somewhat running out of trilobites to prep, and only expecting one or two bugs in the mail. I really hope winter won't be too long!
A belated birthday gift, but only by a day. Had the rock cut and away I went to prepare one of Deb's most prized finds.
From the field to the final product.
Over the weekend, I was trying to prepare an Eldredgeops rana roller so that it would be nicely presented in pedestal fashion (just to get some practice with that approach). The roller itself was flawless with no cracks from crush damage, and fully inflated. It was going very well until it popped off the last remaining bit of rock that had been holding it in place, and... rolled away. Cleaning out my entire prep area did not result in me finding it, so it has likely been absconded by the same little demons who steal socks from the dryer. Six hours of work gone.
So a few days later I decided to prep my way through that disappointment in completing a trilobite I had prepared before, but not to the full extent. This is another Eldredgeops rana from the Penn Dixie site, and measures on the upper end of the size they appear at this site.
Before and after. I had prepared this halfway months ago, but it still needed more work. When I initially found it, the rock had split right through it, resulting in the loss of some segments. I glued it together in the field. In this round of prep, I applied acetone to get rid of some excess glue, performed some restoration of the missing parts, scribed and abraded a bit more, and this is the result. It may not be perfect, but it is a lot better than how I found it! This one measures 47 mm (sag.).
My next task is to complete prep on one of Deb's finds -- another prone E. rana.
The snow has finally buried us after an unseasonably warmer and snow-free stretch. So that means more time spent in prep, and some hunting relegated to the postal formation. This short post is a quick update on newer additions to the trilobite horde.
New acquisition, the blind phacopid Ductina vietnamica. This genus was quite widespread, appearing in different faunal provinces. These regularly come up for sale, but most of them are preserved quite poorly. This one is a much better example of the species.
A semi-enrolled Paralejurus spatuliformis from Morocco. This one differs from other members of the genus on account of having a, well, spatulate kind of pygidium. This one has no colour enhancements, so appears "in the buff" without having been buffed with shoe polish or some other additive to make them uniformly black. The closeup is of the holochroal eye with its tightly packed lenses that appear, from a distance, to be entirely smooth.
While going through some boxes of old finds and turfing junk, I split a small and thin piece of Verulam Formation (Brechin, Ontario) to encounter this cephalon fragment of the rare lichid, Amphilichas ottawaensis. I haven't heard of anyone in my collecting circle who has spent a lot of time in Brechin find more than fragments. I had found a ventral pygidium fragment a few years ago, but nothing else... And now that the site has been shuttered to collectors, there's not much hope in the immediate future of finding more. The picture below is of a complete Amphilichas halli -- not the same species, but it gives a sense of the body plan and where my fragment fits:
And that is likely all that is fit to digitally print this week. The fragment was the big surprise find while the snows are blowing and the temperatures nosedive.
Before my teaching duties resume tomorrow, I was able to squeeze a few more preps in the last couple of days. Nothing significant, but certainly learning moments for me as I better refine my nascent skills.
Already, I can count a few preparation bouts that turned out fairly well: an Illaenus sinuatus, Asaphus lepidurus, Flexicalymene croneisi, and the Flexicalymene senaria / Fusispira nobilis association. So far, so good, and it seems the normal state of things is to be covered in a fine coating of dolomite!
I probed other finds as well to see if there were other things there, and even popped out a headless Thaleops sp. from Bowmanville. Working with sometimes less than ideal equipment can be its own challenge, but I manage. There are still inefficiencies in my preparation "style" whereby it will take me twice or three times as long to complete a specimen than it would a more seasoned professional preparator with a wider array of tools.
So my task queue has been shortening, but by no means at the point where the lab will be going idle for the rest of winter. My next task was to "fill in a gap" in my "prepertoire": restoration. My first attempt was a mixed result on an Isotelus "mafritzae" back in November that has since been finished but I have been remiss in posting said result. This second attempt would be making use of Milliput again, but on a smaller and more expendable trilobite, the commonly found Eldredgeops rana from Penn Dixie. I've got loads of these in just about every orientation.
This bug was never going to make the cover of Trilobite Vogue. It is twisted with tons of crush damage to the glabella and the right side. For added "character," it is also missing a lot of shell. For preparators, this would be the kind of example one would find in a box of rejects to be harvested for parts.
At this point, a bit of scribing around and blasting followed by applying a good glob of Milliput. Some carving and let to cure for a day.
And the last two stages of the process. If you're wondering, the genal area of the cephalon is largely tucked underneath at an angle (super fun to prep - not!). As far as a clean restoration attempt, it is a pretty obvious attempt (but in certain lighting conditions it is a bit tougher to tell). In my weak defense, I don't have tiny tools or tiny fingers to do this kind of detail work. What this needs is a a pin-sized sander to grind and smooth down the transition between the restored area and the original shell. The pygidium itself is a real mess. But, hey, this was already consigned to the chuck-it bucket anyway, so may as well take the opportunity to practice on a piece that I could royally botch.
An incomplete Leviceraurus mammilloides that Deb found in October in Bowmanville. I may have screwed up in an earlier scribing attempt, not figuring that the tail spines would be sitting on top of the bug's plane, so all but the stubs vanished. It was already missing the left genal and part of the right genal, as well as the right eye that I could not save from the impression side, sadly. But it looks a lot crisper now that I've taken the matrix down on all sides and cleared up some of the inter-pleural gunk on this "zipper bug."
While I had the compressor running, why not do a quick blast of this long-tipped Mucrospirifer thedforensis? They clean up fairly easily, but are usually just a waste of dolomite and time.
And these are teed up for their time at the bench: four enrolled Greenops widderensis (one almost completely pyritized) that will be no picnic to prep. The goal with these will be to expose the other side and have them appear as if "draped" over the rock. These are incredibly delicate and flaky, so having at least four on hand to get it right is a good thing as I anticipate at least a few catastrophes with these ones!
It's been at least a day since the last blog post! On this New Year's Day I decided to get into the lab for one last go at preparation of fossils before I have to hunker down and do preparation of courses for this semester (I rarely need air tools for the latter, heh).
I found this association piece back in 2017. Initially when I found it, just surface collecting the upper floors of the quarry in Brechin, I put it in my bucket thinking it was just a gastropod steinkern. A few weeks or so later, looking over my finds, I noticed this traveler after removing some dirt.
At the time, my only prep tools were a pin vise, a Dremel, and a lot of patience. A trilobite this small would require air tools as the matrix is too hard for a pin, and a Dremel would vibrate this to pieces. So it was left consigned to the "to-prep" pile and forgotten. After having some good rounds of prep in the last week, and a little boost in the confidence of my prep skills, today was the day I'd tackle this wee bug.
The trilobite is Flexicalymene senaria, which is one of the most common trilobites in the Verulam Formation (Ordovician). Hash plates are filled with their moulted cranidia and pygidia, and they are also frequently found enrolled and matrix-free. Full prone ones are a little less common, but in no way rare. What makes this one special, though, is its association with a steinkern of the gastropod Fusispira nobilis.
After four hours of very careful abrasion work, this one is done. It may seem counterintuitive, but smaller pieces do not necessarily equal faster or easier prep work. Much more care and attention is required, and the margin for error is much smaller than when working with larger pieces in similar matrix and preservation conditions.
And so here it is in all its close-up glory. Nice, prone, and robust with just a few minor problems. Prep for 2019 is off to a great start.
Before 2018 runs out, a trip to the lab to prepare this semi-prone Asaphus lepidurus, the more common asaphid found in the St Petersburg, Russia quarries. Also, a new trilobite addition.
This is what it looked like before starting. The pleural orientation makes it clear that the cephalon will be projecting downward as this bug was buried in the process of enrolment. There is some damage to the final pleural segment before the pygidium. The initial challenge was getting rid of the tall stack of matrix on top of the bug using only my ARO clone with factory tip.
The GIF above shows the process after four hours of scribing and abrading. You know those preps of Russian trilobites with the soft and easy matrix due to marl content, the stuff that comes off like butter? -- Yeah, this isn't one of those. Instead, the matrix is hard with calcite crust. It is the kind of stuff that you can't risk getting too close with the scribe for fear of dinging the bug (or drilling through!), and the stuff that laughs at the air eraser even cranked up to 75 PSI. Even pin vise pricking is not able to gain enough purchase to separate matrix from shell. I'm going to have to risk approaching it blind from the anterior side in the hopes that I can locate the cephalon, working my way out and eventually freeing the left side pleurae.
The orientation is not the easiest to work with. Being semi-prone means the pleural segments tend to bunch together and are a bit more fragile... One misstep means losing shell pieces. By contrast, the axial rings are stretched out to their maximum convex flex, and that can lead to other problems such as shell thinness.
Four hours became eight hours. Eight became seventeen. The matrix was sticky and pretty much immune to dolomite abrasion. So it was the delicate and less than ideal process of using the vibrating scribe tip to "kiss" the matrix to cause it to flake off, and some matrix shaping to level down the bug's contours as well as expose the cephalon. The latter took a very long time. You can see the scribe dings in this image, but those are easy enough to fix. Now comes the finicky job of removing all the hard grit between the segments.
Success! The stubborn matrix grit is gone. The only disappointment is that this one seems to be missing the lowermost left pleural segment just anterior to the pygidium. I had been careful to level down slowly, so I didn't accidentally scribe it off; I think this is just moult-related damage, and that is made more likely by the slight misalignment of the pygidium in relation to the thorax. It happens!
Also missing a wee bit from its left eye, but on the whole a half-decent prep.
This delightful diminutive phacopid had come in the mail. From what I read, it was collected about 50 years ago from the classic "trilobite fields." Gerolstein, Eifel mountains in Germany, Ahrdorf Formation, Flesten Member. I'm told this site is no longer available for collecting, so makes this trilobite extra special. It measures just about 1 cm across the transverse axis.
While moving some spare rock from the living room to the basement where I keep my spoils, spare parts, and fossil graveyard, I decided to break open this big block I kept from my recent trip to Bowmanville. I managed to expose a bit more of this Isotelus fragment. Six out of the eight thoracic segments are visible and part of the pygidium. Had this monster been complete, it would have measured about 28 cm in dorso-saggital length! Apart from the rarity in finding such extra large isotelines, that is made more so by the fact that the very largest ones rarely preserve well being subject to more exposure, crush damage, etc. It is for that reason Dave Rudkin's team's find of that Iostelus rex in 2002/3 was such a coup (72 cm in length -- the biggest trilobite on record!). It is a bit tougher to make out the species on this one, but I'd wager this is likely an Isotelus latus. Now to wait until May to find a complete one!
But let me sneak in just one last prep before wrapping up the year. This is a
Flexicalymene croneisi that Deb found in Bowmanville in October, and I've been meaning to clean this one up. Pictured to the left is after I've done some preliminary work, and on the right is the complete deal. One hour prep. The pictures don't do it justice (it's still dusty and has some dolomite dust in the cracks, and the iPad is not the greatest for macro shots), but I'll take a better picture before putting it in the trilobite gallery.