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.
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.
There are collecting locations that I'm not likely to get to in the near future, and as much as I'd love to fancy myself wealthy enough to just buy up every great Russian Ordovician bug, sometimes one has to settle for the discards.
Russian preparators who eke out a living collecting and preparing trilobites are not too different than the preparators who do the same thing here: there are those (far too many) finds that are simply not worth the time and effort for whatever reason. It could be a common bug that has too much compaction damage, bad mineralization stains, too many missing parts, or anything else that might result in producing a trilobite that is far less than A-grade for sale. Buyers generally expect perfection, after all, or something close to it. So into the chuck-it bucket it goes. I have my own "graveyard" of partials, botched prep attempts, and stuff far too common yet complicated to be worth preparing unless I had nothing else in the queue.
So this is the chuck-pile bug in question. Not quite complete junk, but pretty close. It was likely found busted and glued together in the field, which is a fairly common scenario when collecting from these layers. For every nice, full (sometimes floor polish enhanced) Asaphus sp. one sees for sale, there were likely hundreds of busted up partials (some of which get recycled as grafting material). This trilobite has a lot of problems beyond the fractures tentatively held together with glue: crush damage, missing shell bits, and serious mineralization discolouration that makes it appear mottled and less than pristine sale quality. But I need the practice!
I've never prepared an illaenid before, and there are always a few "firsts" I encounter while preparing given that I haven't been doing it for that long. Each prep is a learning experience, and making serious mistakes is part of it... But so is recognizing that each prep is different, even when dealing with the same species and matrix. You try different approaches and techniques, sometimes using a wide range of tools suited just for that particular job.
So, let's have at it.
The first step was to do the scribe work, but not before consulting numerous images of this species from different angles to give me a reasonable idea of what to expect while my scribe flies blind. My scribe sailed through this matrix! By contrast, the previous prep of an Asaphus lepidurus was a dismal failure as the matrix was a dense, calcitic mess that even 75 PSI dolomite wouldn't touch unless I wanted to eat through several canisters of the stuff.
The unique aspect about this genus is that the bulbous cephalon seems to go on forever. This was where I stopped the night before, and there was still a lot more matrix to remove. When they preserve in this kind of almost semi-prone state, it is customary to just blitz off the the anterior side of the matrix, which gives this burrowing bug the appearance of "hanging over" the side. This is all scribe work: I just needed to "kiss" it with the tip and the vibration would knock off the matrix without me risking hitting the shell with the scribe tip.
And this was where I had to call it a night... Not just because I didn't want to run the air compressor beyond 10 pm and be a loud nuisance, but on account of the other result of such a soft and yielding matrix is that fractures emerge that run deep and threaten to wreck the trilobite. Pictured here is my stabilizing some vibration-made cracks by wicking some cyanoacrylate. A good ending point for the day to let it cure and get back at it in the morning.
As soon as my missus went to work, I was firing up the compressor for round two. At this point, the scribing work is pretty much done as far as I'm willing to risk it; what remains are some delicate areas that need to be air abraded. I do alternate between scribing and some air dent to test certain spots, but I'm a task-switcher by nature. The tricky spots are going to be the eyes and the genal spines.
It isn't a true prep session unless you experience a minor catastrophe (at least that is the norm for my inexperienced self!). The very thin-shelled underside of the cephalon didn't quite dig my air abrasion action, and so some shell bits went flying. I retrieved a few pieces, which is not easy to do in a dust layer in the blast chamber (or in the shop vac bag). And I don't exactly have those tiny fingers adept at threading needles. I reattached a few of the pieces I found, but some of them were lost forever. It could have been much worse, and I managed to fill in the much bigger "bald spot" with the pieces I could glue back on. This is a discarded bug anyway, and not a presentation to the Queen.
Air abrasion work reveals the eyes and frees out the gunk between the pleurae and the genals. I've moistened it with some oil to better detect other areas I might have missed.
Yes, I am such a prep noob. I will, however, take immense pride in how I managed to free up that genal spine (which had a crack in it, no less) to be my first "flying genal spine." For those who do not prep, this may seem very easy, but it is fraught with a lot of nervousness and care to ensure not blasting the spine off as a sacrifice to the hungry shop vac!
And this is where we are. I also sanded down the matrix (decided to leave a bit for aesthetic reasons). There is some cruddy glue stuff on the left pygidium that needs an acetone bath (abrasion is too risky at that section), but otherwise not bad at all for preparing what had been consigned to being a junk bug. I learned a lot, and ended up cussing a lot less while doing this one. To me this is a prep triumph.
Amidst teaching and grading, I am spending some time at the prep bench. Deb got me an early xmas present: a much-needed shop vac as the fine dolomite dust covering everything in the basement is a sign that it is also coating our lungs! I'll be hooking up that bad boy this week.
After the recent Bowmanville trip (post here), prep has begun on a few pieces while leaving much of it for winter. I've also been voraciously reading several trilobite papers as of late during my long bus commute. But this post is more of an odds and ends one.
Kicking it off would be ongoing work on my Isotelus (likely I. "mafritzae" morph type "B"):
The going is slow when the rock is dense, and the bug is flaky. During a quick exploratory abrasion, I had that heart-stopping moment of a piece flying off and miraculously located it in the dusty, bit-strewn blast box (that I can now clean out with the new shop vac!). It was some cuticle from the occipital ring that I glued back on. The eye is intact, and I suspect the other one will be as well. This one is tucked into the plane on an angle, so that means a lot of long scribe work to bring it down. Nothing can be easy! In this case, it will be worth it, as it is only missing a few tiny pieces from natural weathering, and already seems to measure 90 mm.
A few weeks ago, my fossil comrade from Texas, Kris, sent me hot peppers he grew and dried. We are both hot-heads and love our super hot peppers. This nice selection includes the famous Trinidad moruga scorpion that taps out at over 1.2 million Scoville Heat Units (that is about 3-10 times hotter than a habanero). I am keeping a few in the freezer to seed and plant next year, and the rest were turned into hot sauce. The process is fairly simple: sterilize the jar in boiling water, reconstitute the dried peppers in boiling hot water for 15 minutes or so, cut off the stems, add vinegar and salt, puree in a small blender. But this is a fossil blog, not "Kane's Kitchen"!
Kris perked the package with some fossils! Here are some ammonites and a reptile vertebrae from the upper Cretaceous.
Some really neat fish and shark verts, as well as a shark coprolite -- also all from the upper Cretaceous.
A very cool pyrite piece showing the cubic crystallization state, and exceptionally well preserved and detailed leaves from the Eocene.
Those leaves truly deserve their own photo. In the interim, I've been putting a very Canadian package together to send his way.
I really hope to get out to collect one more time this year, likely to Arkona. That will depend on weather, opportunity, and the healing progress of an ankle I sprained pretty badly. If not, then I suspect the next few posts will be detailing preparation progress and a round-up on a year that has been hit and miss.
Had a pretty good time at the biannual collecting event in Bowmanville (east of Toronto). Although the first half was a complete and frustrating bust, the second half was when our luck turned. I've some prep work to do, but some field fresh finds should do for now.
Here's our crew. It seems that ever more people are coming out to this event. The quarry is so vast (six levels), that even with this many collectors poring over the blast piles there is plenty of space and opportunity to make some lovely finds. It's also nice to talk shop with other fossil-hounds. The main attraction are trilobites, and particularly large Isotelus.
Finding a complete Isotelus pretty much necessitates scanning and splitting through a lot of rock that are filled with moulted partials, some of which can be quite large. Pictured above is a few of the larger partials I took home, and one can imagine how big they might have been complete. And this is nowhere near as big as these can get.
Midway through the day, our luck started to turn. Pictured here is a Leviceraurus mammiloides of some significant size. Although the left genal spine is missing, the right eye is in the impression side, and I can prep out the pygidium to expose the long spines.
A not so great Ceraurus. As an added thrill, they can also be quite flaky. I can use this one for prep practice. The cephalon and thorax should be relatively complete.
Poorly lit photo, but I'll retake it once I give this one a quick blast with the air eraser. A fully intact, perfectly round and enrolled Flexicalymene croneisi -- a new species in my collection. You just have to love the duck-faced look of these.
Possibly a Thaleops on the left, and a Flexi on the right. Both obviously require some prep.
What I really came for: Isotelus! This being my third trip to Bowmanville, I had never found a complete one. This one has its head tucked into the matrix, so there is a chance the eyes are intact. In most cases (when the bug is exposed), the eyes are sheared off from blast damage or weathering. On the right was a small consolation specimen I picked up in case I didn't find a full one.
But wait, there's more! Well, not so much more in terms of trilobites (I have a few others I haven't added here yet). This big nautiloid chunk was worth taking home.
It's always good to break rock with good folks. It is always a great pleasure to meet up with Kevin B. with whom I've had collecting adventures. A professional preparator by trade and trilobitologist, I had entrusted him with a very delicate and challenging preparation job of three notoriously thin-skinned, enrolled Greenops widderensis from Arkona. The genal spines and lappets were flying. In the process of prep, Kevin found a fourth one on the plate. This is incredible and painstaking work. Here are a few other closeup images:
So, in all, a great time in the Lindsay Formation. And now the prep season begins...
While I had the compressor running, I figured I'd do a quick blast on what will probably be a very challenging prep this winter, as well as preparing some "low-hanging fruit" in the form of a prone.
First, the investigative quick air abrasion blast on this Greenops widderensis roller with flying genal spines. This one will certainly be a major challenge to do without screwing up. I'll probably end up cutting the rock a bit above the spines and delicately work my way down to reveal the other side.
This was the low-hanging fruit: a small Eldredgeops rana prone from my Penn Dixie weekend. The matrix is very thin on one side, so there was the risk of the trilobite flaking.
I just came off a fairly disappointing dig in the field where the group of us pretty much got skunked. It would appear our grand bench we created and extended so well this season has been tapped out. It was tough work, and several visits, but I think we extracted some real gems there this year, so I'm not too sad. But between that, my own nearby honey hole tapped out as well, and a quarry that is now shuttered to collectors, the trend moves steadily toward collecting sites going the way of the extinct arthropods I collect. That doesn't leave many local options, and so more trips to the US become an inconvenient necessity.
But apart from the doom and gloom of all that, a few items of note on the home front.
I haven't really taken pencil to paper in about 20 years, so sketching feels as natural to my hand as trying to sew a button with my toes. This was a 15 minute sketch of Asaphus punctatus using a 9B pencil. I can see where I goofed, but to be fair I am out of practice. Perhaps this is something I should take up again? I gave it up long ago with the advent of art-making software that seems to have rendered obsolete the old hand/pencil/paper triad.
What is this strange box sitting on top of my prep bench? That is a much-needed blast box so that I'm not filling the air (and our lungs!) with dolomite powder when using my air abrader. I needed a blast chamber with a flat top, not on an angle, but stores like Canadian Tire and Princess Auto only sold the latter type. I got in touch with my collecting comrade Malcolm who custom made this box using his ingenuity and an affordable array of parts. Using a double-sided press-board, getting the cuts just right, using weather-stripper and latches on the side to secure the top, adding picture glass (you never use plastic as it will scratch and fog), and sealing in an attachment for a shop vac to create negative pressure, this box is ready for some serious work. I'm going to need a sectional on the right for some of my other tools etc., but I've already connected my air tools that are now sitting ready in the box.
About 7 bucks in parts here. This is definitely something that makes preparation that much more convenient. I purchased a manifold blue block and two double-ended male 1/4" attachments so that I can run both my scribe and eraser from the same line without having to swap them out all the time. Now the only thing I have to do is remember to adjust the pressure when switching between the two (I run the scribe at around 100-110 PSI, and the air eraser at 10-50 PSI).
I'm almost there! The last big thing I need is a much bigger capacity air compressor. Other things like a Chicago Pneumatic 9361 for bulk matrix removal would be nice, but I can probably get by without one for the time being. I still need to do a serious reorganization of the prep area to optimize on the small space.
So with site locations drying up, not quite sure when my next dig will be. Still, there will likely be fossil-related activities in the offing, so stay tuned and thanks for stopping by.
I'll end with a nod to Don McLean:
Bye bye, Devonian pie,
Drove my chisel in the Widder, but the Widder was dry.
Us good ol' boys who hunt Arkona now cry
saying 'this'll be the shale that won't supply.'
No rest for the weary! After the big multi-day dig, I was up in Barrie helping to downsize a house and got to keep some supplementary tools that will help at the prep bench and in the field. A selection of awls, sandpaper, tiny screwdrivers, and even a fish knife all come in handy when paired with the precision tools I use.
So began a bit of prep.
This is the placoderm plate that I chased to its end. I'm thinking it is a plate from Protitanichthys rockportensis.
I'm always looking to hone my preparation skills, so practicing on less than perfect trilobites is ideal. The one on the left is by far the best of the two, but could still use some restoration on the right side by grafting a bit of cephalon and the right genal spine.
Small and battered, this goniatite is now clean.
Although incomplete, this Tornoceras unioangulare has some stunning detail after I put it under heavy abrasion.
A pity this one is missing a few pieces, but not a bad preliminary prep if I do say so myself!
Some of the other trilobites are going to be much tougher work, and they are also missing pieces. The main thing is that my prep skills are improving with practice. Beyond that, someone from the University of Calgary has shown some interest in the placoderm pieces I pull from the Widder Formation. There is a remote possibility that I might have something new to science, but who knows? Just as a refresher, two previous placo pieces that might be worth studying:
It's just too darn hot to go out collecting these days, but I'm really hoping to get out there relatively soon, if not also a possible trip to Western NY pending Deb's work schedule.
I managed to spend some time this week preparing a few of the finds from Penn Dixie. It looks like I had a few more full trilobites than I had thought, so there was a good deal of material to practice on.
Preparing these Eldredgeops rana is a fairly straightforward job. The shell is thick and forgiving, and there are no big spines, flaky lappets, complicated horns, and the like to present much difficulty. I managed to prepare three, which I'll show in ascending order by size.
Bug #1 - 1.7 cm
This one was fairly small, but I had recognized it as being complete in the field, and my friend Malcolm was able to chop it out of the block with his saw. There are areas on this where I could have bit in a bit deeper around the sides and the anterior of the glabella, but these smaller ones can be a bit tricky. I may take this one back to the bench for some detail work.
Process: a quick trenching with the ARO clone air scribe, some spot work with the pin vise, and three rounds of blasting at 55 PSI using dolomite and the Paasche AECR. No finishing oil applied.
Time: 25 minutes
Bug #2 - 3.8 cm
This shows a before and after picture (in the field, and after prep). This was one of Deb's finds, so I took care not to screw this one up! There is some slight damage to the left side pleura near the ridge of the cephalon, and some damage to the right side pleura as well, but in all not a bad prep.
Process: Alternating between ARO clone scribe and Dremel, pin vise work, multiple rounds of dolomite blasting (20-60 PSI) using Paasche AECR. Finishing is just a light oil to bring out the detail, but it fades back to matte.
Time: 90 minutes
Bug #3 - 4.6 cm
Before and after
This big bug had some issues. When I found it in the field, it had been cleaved diagonally, so there is some missing pleurae bits on the upper left and lower right where the rock had split. I wrapped it up in a secure container, and when I got home I used cyanoacrylate to stick the pieces together with some clamps, and suitable time for curing. Despite the ugly fracture mark with some stubborn glue, it looks okay. I may take to trimming the excess matrix on either side to better centre this bug.
Process: The right side had a lot of bulk matrix which took some time to scribe off. I trenched around to reveal the tips of the pleural segments and cephalon features, sculpted the surrounding matrix a bit to even out the jagged parts, sanded off the scribe marks, and blasted it with dolomite (25-55 PSI) with the Paasche AECR.
Time: 75-90 minutes
There are a handful of others that will need prep, including both prones and rollers. With time and practice, I am doing much better in terms of technique - but there is still a lot to learn. Fortunately, I'm in no hurry and will hopefully have decades to fine tune my preparation skills.
Here are the others in the prep queue: four rollers and two prones: