While I wait for some material to arrive, I snuck in a prep of a Rust Walcott plate with six Ceraurus pleurexanthemus. Most of them are very small (a few millimetres), but the central one is also the biggest. Smaller trilobites in this material take much more care with abrasion at lower PSI and good powder control as they are very easy to blow right off. My good fossil friend who put this in my hands over a year ago cautioned me to take it slow, and possibly wait until I had much better tools. I took the risk, but certainly took it very slow. The plate in its initial state: And the final result:
A year after finding it, and 155 hours of prep, and I can finally put down the tools and take a breather. Many were the times I wanted to quit this one, but I remained dedicated and determined to see it through on account of its size, and location. Giant Isotelus gigas are known in Quebec, but almost always as fragments compared to Ontario where they are more commonly found whole (but it is still a rare delight to find one in Ontario, too!). I've posted about this one already at an earlier stage of the process here. The amount of matrix was obscene, and the dense nature of the rock was murder on the tools, which meant agonizingly slow going. I abandoned it for almost a year. The preservation is crappy -- flaky, delicate shell that blows off with even the slightest vibration, missing parts, the works. This is how I found it in the field. Just look at all that tough rock sitting on top of the thing! The number and variety of tools and accessories that were used to get this one prepared could run a whole page. Everything from rock saws, angle grinders, Dremels, scribes, abraders, tape, brushes, putty knives, Milliput, Bondo, files, sandpaper, glues, fixatives, paint, etc. What an ugly brute, and this was after 20 hours of additional scribe work. It is missing eyes, cheek skin, most of the pygidium, half of the pleurae on one side, and for added enjoyment the anterior part of the glabella is displaced and shifted. The bigger the bug, the higher the likelihood of problems. The first task was what to do about that glabella -- it looks ugly, and preparing it as-is would have really detracted from the piece. Problem, meet (extreme) solution. I just scribed the thing off entirely leaving only the "footprint." I took a photo of that and fed it into my Camera Obscura app, hollowed out an area just below the intact glabella, and then projected the footprint onto the area where I placed it where it should be, used a marker to plot it, and tried out some initial restoration using Milliput. In place, and while I was there I decided to replace the missing skin on the genal spine, and used a sewing needle to make the little pores. As I knew I would have to be building some new parts, I relied on Rudkin and Tripp's excellent text where they indicate the proportional ratios. I opted for a flat and conservative 50% width to length ratio. Milliput is not cheap, and certainly not to be used as fill. Since there was a huge chunk missing out of the right pleural area, a fossil prep expert friend of mine suggested I use Bondo to form a base, and then apply milliput on top of that. On the right is a preliminary shaping of the pleurae before more detailed work of carving and sanding with varying sandpaper grit. A similar process was followed for the pygidium. After, it was a matter of stabilizing, some sanding, painting, and other little finicky details. The result is not perfect, but I've never attempted a reconstruction to this extent before. I toyed with building a whole new cheek on the right side as it is smashed inward, but then that might have thrown off the rest of the trilobite's proportions, so I opted to keep it as-is. And there it sits in its big, ugly glory -- a bit like me! What a long process. It has just about every conceivable problem, but I felt this one deserved a chance. At 11 inhes, it is by far the largest trilobite in my collection.
So, when is my next big trip? I hope in July. I have something in the works that should see some prospecting adventure somewhere far away. I might sneak in another prep before that happens, but for now I am taking a well deserved breather! And a shout-out to Bill who was immensely helpful in giving me both great information and fantastic conversations on the phone, so I could pick his brain a bit while I was on site! Those who know which Bill I am referring to are likely part of the same niche group of fossil hounds of Ontario, and he is certainly a treasure. So May has been a slow month where I visited six local spots to no real great gain, but a month-end trip that saw me taking the train out east to Hastings County to do some exploration of the Bobcaygeon and Verulam formations. These are not "premium" spots for those formations on account of some wonky preservation and a lower volume of trilobites compared to the equivalent strata in the Lake Simcoe area. But, since there is virtually nowhere in the old spots that are legal to dig, needs must as the devil drives to visit lesser locations. Here is a selfie of your intrepid adventurer en route to the location. I do like riding the rails as being the more relaxing travel option. This was a weekend quickie, a burn and blast blitz. Once I got settled into my motel, I had the whole weekend to go digging. Upon entering the site, this was my first greeting -- and a good sign. This Ceraurus is terribly weathered and incomplete so I did not take it home, but certainly a good way to start the day. One very neat aspect of this material was how frequently Ectenaspis appear. Although rare, they are a bit less rare here. But this material is also quite turbulent, and so parts are more likely. Here are two pygidia with the one on the right being a juvenile. That little "lip" at the tip is the sure giveaway to discern this elongated and enigmatic asaphid. Isotelus were also present, but almost always as fragments alone. In this case, two-thirds of one appearing some pretty nasty matrix. A good eye can spot the weathered Ceraurus at 5 o'clock. In fact, if I had a dime for every weathered impression of a complete Ceraurus I encountered, I am sure it would have covered the cost of the trip! The number of ribs on the narrow pygidium gives me the impression that this impression might be something like a Calyptaulax, but it could also be just a Flexicalymene (which were fairly numerous). The cephalon on the right is clearly a Calyptaulax. Speaking of Flexis, they were present. Not all of these survived, though, as they wanted to congregate in the middle of huge blocks, and all I had for extraction tools was a hammer and chisel. The bottom two survived, with the upper left not worth getting and the upper right specimen a victim of extraction (I was going for something else). And this was the "something else" I was trying to extract, a Gabriceraurus. In the very middle of the giant block, set on a thick hardground that just shatters rather than comes off in a nice sheet. Suffice it to say, I did get this one out... in two pieces. The pygidium is tucked under, and our friend Bill speculates that this may be indicative of the female of the species as many do appear with this pygidial folding at the eighth segment, possibly suggestive of protecting eggs. A positively giant Gabriceraurus missing a lot of parts. I kept it on account of size. On the right, a heartbreaker weathered prone. Scanning surfaces carefully (which I did -- every one of them!) can yield up finds, but they will more than likely be damaged and weathered. The better material is through splitting, but the material for splitting was sparse (either too small or way too large), and the matrix somewhat ugly. Smaller Gabriceraurus plattinensis. Only the one on the left survived extraction while the one on the right was sacrificed to the fossil gods. It is missing parts so likely just something to stick in a box. It is said that Erratencrinus vigilans are relatively common in this material, although I only found fragments: a cranidium and a pygidium are representative of my collecting efforts. Some of the effaced trilobites did appear, although just once each. A battered Bumastoides and a headless Thaleops/Nanillaeanus (KB would howl with indignation if I didn't include the historic name!). I'm quite bad at taking photos on a more regular basis as I'm so caught up in the hunt, but an obligatory "context" shot. Brachiopods were excessively numerous and were second in volume only to burrows. Lots of burrows. Echinoderms were mostly represented by the occasional long crinoid stalk with no terminating calyx, but I did encounter two examples of cystoid. This Pleurocystites was extracted in two pieces, free of matrix. Here is one of my prize finds, and a new species for the collection. Although they are said to be common, this was the only example I found of Cyphoproetus wilsonae. The very thin shell is in the negative, which I also collected, but they are virtually impossible to prep that back together. It is good as is. Be still my trembling heart, a complete-ish Gabriceraurus plattinensis (our friend Bill has good reason to want to park this in the genus of Ceraurus, but such are the vicissitudes of taxonomy). It is missing an eye + palpebral lobe, a pygidial spine tip, and a notch out of the axis, but I have since prepared this and restored much of what was missing, and it looks lovely and somewhat 3D. That will be the subject of a subsequent blog post.
So, overall, two full days did yield some goodies, although not as many as I had hoped. In terms of "value," I broke even on the trip. It was a bit of a slog in this material, and I performed my due diligence to scan and split anything viable. There were some heartbreaker moments, but I was buoyed up by some pleasant surprises. Would I return to this site? Not likely. Whatever could be got has likely been got. Having the Devonian around me, I sometimes forget how exciting the Ordovician can be where finding fragments is a disappointment compared to that being thrilling around here! I really should post more often to avoid these long silences. My bad to fix. Until hopefully soon. |
Kane Faucher
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