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.
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.
Made a trip to the post office to pick up a backlog of packages that couldn't be delivered at the door, and it was a lovely little bonanza of bugs.
Although a bit beat-up and sticky, this will be added to my winter preparation queue. This Ordovician corynexochid is Illaenus sinuatus, a new species for the collection. The cephalons on these kinds of burrowing bugs tend to be fairly robust, so there is considerable matrix to be removed. I'll post the complete results once I get this in the lab.
Another Ordovician trilobite, the phacopid Pliomera fischeri, from Kinnekulle, Sweden. Trilobites from the Swedish part of Baltoscandia do not tend to preserve as well, and can come out fairly weathered.
From Haellekis, Sweden, an enrolled Ordovician phacopid, Nileus armadillo.
Although I already have two other examples of this species, a small and enrolled Asaphus kowalewskii will nicely complement the Russian asaphid display.
Top prize for this bug bonanza would go to this lower Devonian Moroccan phacopid, Wenndorfia planus. Nicely enrolled, and uniquely prepared in a tilted pedestaled fashion to show off its "assets," this trilobite was reassigned by Sandford (2005) to Wenndorfia from the species Parahomalanotus... which in itself was possibly mistakenly elevated to genus status. For those interested in some of the twitchy taxonomic tango see:
Sandford, A.C. (2005)
Homalonotid trilobites from the Silurian and Lower Devonian of south-eastern Australia and New Zealand (Arthropoda: Trilobita: Homalonotidae).
Memoirs of the National Museum Victoria, 62(1):1-66
Basse, M., & Franke, C. (2006)
Marine Faunen aus dem frühen Unteremsium (Unterdevon) des Givonne-Oesling-Antiklinoriums (Luxemburg).
Chatterton, B.D.E., Fortey, R.A., Brett, K.D., Gibb, S.L, & McKellar, R.C. (2006)
Trilobites from the upper Lower to Middle Devonian Timrhanrhart Formation, Jbel Gara et Zguilma, southern Morocco.
Palaeontographica Canadiana, 25:1-177
A number of trilobites came in the mail, with several more waiting at the post office and some in transit. First up is a Paralejurus dormitzeri
This fairly common Devonian corynexochid from Morocco does appear fairly often for sale, but a lot of them are the victims of quick and brutal preparation. This one has very good quality preparation, with some minor restoration on the lower right pygidium. Finely detailed with the eye lenses, terraced growth lines, and pedestaled to show the cephalic doublure. Only a few scribe dings, and measures close to 80 mm.
A cute and small Asaphus kowalewskii. Although I already have an example of one (semi-prone), this young holaspid stage specimen was too adorable to pass up. Some slight compaction between the third and fourth axial ring, but virtually no restoration of this stubby-eyed example of the species.
Hooray! Another winter prep project to keep from going bonkers from fossil hunting withdrawal. This is a relatively small semi-prone Asaphus lepidurus.
Until tomorrow when a few more trilobites join the collection...
Recently returned from two weeks in Jamaica, and particularly in Ocho Rios (St Ann's Parish). The primary purpose of the trip was undoubtedly much-needed R&R after a hectic semester, so swimming in the ocean, drinks by the pool, and the usual laying about dominated our time there. Still, the lure of fossils is always strong.
About 75% of Jamaica's rocks are limestones dating back to the late Mesozoic and Cenozoic. The formation of Jamaica as it stands above water today was the result of successive volcanism. Today, it is surrounded by a diverse coral reef marine ecosystem, and has some mountainous peaks (primarily Blue Mountain, the base of which we were staying). The limestones themselves are almost entirely dominated by coral fossils, with some gastropods in the mix. The limestone is quarried from many areas and used extensively for local building needs.
When these appear as large blocks sitting around, closer inspection reveals that much of the rock is fossil coral. Pictured here are some examples, including a scleractinian coral colony.
Sadly, despite some efforts, I could not arrange to go off property to inspect some larger, natural exposures. Some exposed beds at larger quarrying sites or roadcuts rise to over 200 metres.
Pictured here are just a few of the shorter roadcuts, snapped from a moving shuttle bus. These are fairly typical of the island's limestone beds, although not pictured here would be the strata that is more of an orange-brown.
With such an abundant supply of limestone, it is used in many ways. These saw-cut patio tiles around one of the pools contain cross-sections of high-spired gastropods of some considerable size.
More poolside tiles with fossils.
I'm sure there would be some issues if I decided to extract this from the pool side, but it would be neat to be able to prep out the other side in 3D.
There are little spoil piles in out of the way places everywhere. Some of these are discards from being shaped into wall pieces, or stuff to be used as filler elsewhere. I went poking around on the fringes of the property, behind all the resort action. All coral fossils. It's not easy to go scrambling over piles in your flip flops.
This scleractinian coral fossil was my keeper from these piles. I later cleaned up all the dirt pictured on this one, and it looks nice. With luggage weight requirements, I really can't be hauling back anything more than fragments!
Case in point would be this chunk (closeup detail on the right). This stuff is very dense, and without a hammer it becomes nearly impossible to crack out a piece without turning it into dust while bashing against other rocks.
Some in situ pics along the beach where the cliff was close to shore. This stuff is fairly resistant to the pounding of the waves.
Not all the patio material is derived from fossiliferous rock. Pictured here would be "fakes." The left side depict tiles that are clay and based on a mould. The one on the right is simply poured concrete with a sectioned modern shell. Using large leaves as imprints on the wet concrete give it a neat aesthetic.
Ok, so no big fossil haul, but still interesting to bump into fossils while on vacation. When I came back home, there were a number of packages waiting for me, with others waiting for pick up at the post office., They are all trilobites, with a few for me to prepare. Stay tuned...
On a grey, snowy day, Deb and I paid a visit to the annual London Rock and Mineral show. Shows like these are heavily dominated by vendors who specialize in minerals, jewellery, healing crystals, etc., but there are tables with other stuff as well, including space rocks, microscopic crystallization displays, the local rock club, and the local university's earth sciences department. Vendors specializing solely in fossils were uncommon, and one could encounter a few fossils among the sale items by the mineral specialists as well.
In terms of fossils, a good bulk of them are the typical fare of polished Moroccan orthocerids, polished Madagascaran ammonites, eminently displayable Green River fish from Wyoming, and standard trilobites (common Moroccan phacopids and proetids, mostly, and the usual flush of Elrathia kingii from Utah). Some neat stuff like shrimp from Solnhofen, petrified wood, and the like as well.
The real highlight was in speaking with two vendors, both fairly aged, who are still collecting, and with one collecting locally. There are certain names of collectors, sites, and species we know as we talk shop. It is a small world! One vendor actually knew Charles Southworth personally, so that was a local bit of history.
I didn't buy much, as there wasn't much of interest I wanted to buy (or prices were marked up far higher than what I could acquire them for elsewhere). But, I did buy two things.
A sealed, new copy of what is a kind of trilo-bible for NY collecting (with some significant overlap with similar species in Ontario). I already had the digitized copy of this in my rather robust trilobite book and article library, but sometimes nothing quite beats having a physical book. The photo plates are very nice, and I suppose it may be better to drool on paper rather than on a screen.
And the other purchase: cephalon of an Eldredgeops iowensis southworthi. I don't usually purchase fragments and partials, but it just so happened after all the conversation about Arkona and Charlie Southworth that I figured I'd pick up the trilobite named in his honour. These ones are quite rare to find in the Hungry Hollow Member (a collecting comrade managed to find a full roller of one last October, the lucky duck!). The sheer size of this phacopid is impressive, even in fragmentary form. It differs from the standard Eldredgeops rana mainly in terms of the highly tuberculate sculpture. I do have a small pygidium of one collected some years ago, but this seemed too special to pass up. The vendor I bought this from extended an invite to visit his shop up the highway, and maybe an opportunity to collect with him.
And that's about it this time. With ongoing labour strife with Canada Post, I have a few items coming that will likely be delayed for some while. So far, I am still waiting on some Milliput for restoration work, and two Russian trilobites to prepare (one a new species of Illaenid for me, and the other an asaphid I already have two examples of, and will probably prep and flip).
Until next time...
Unless by dint of some miracle the snows melt away, I think I'll have to call the season. This year has had its highlights and its challenges, and so I would class it as mixed in terms of collecting success compared to 2017. There were some notable challenges this year:
* Late spring and early winter definitely truncated the season.
* An overly hot July and rainy August + scheduling conflicts meant less trips
* My backyard honey hole is pretty much tapped out
* A premium Ordovician collecting site was shuttered to collectors this year
Trilobite collecting diversity was a bit low. Whereas last year I had managed to collect 14 new species, this year's total was only 4. The surge in species acquisitions was mostly supplied through purchases and trades.
Of the trips made this year, a roundup:
* 10 trips to the backyard honey hole with one exceptional find
* A combined 6 days at Penn Dixie (late April, early October)
* My first trip to Deep Springs Road (late April)
* 2 trips to Bowmanville (May and October)
* A combined 15 or so days in the Arkona area
Due to a lack of more local viable sites this year, it meant many of us had to fall back on focusing our efforts on the Widder beds near Arkona, and we managed to excavate extensively this year. The finds were quite good (numerous full Greenops widderensis, placoderm plates, pyritized cephalopods), but somewhat repetitive.
Serious collectors up here in Canada are a little like squirrels. We try to collect as much material as possible for preparation over the winter. Pictured below is 4 of about 5 or so beer flats of material for preparation.
There is more than what is pictured here, but it isn't preparation riches.
Two new areas of focus certainly mark the year. The first has been in the gradual improvement to both my preparation tools/area and skills.
2018 saw the inclusion of that handy trolley, the manifold block for the air tools, a blast chamber my fossil comrade Malcolm made for me, a shop vac, and a new sturdy stool (previously, it was a too-low kitchen chair where the seat was propped up by boxes of rocks with a cushion atop it -- hardly comfortable or convenient). Other stuff include the usual tools of the trade (not all pictured): scrapers, blast media, glues, blades, brushes of all sizes, portable cases, etc. I also now have a nice display cabinet for the trilobites in the living room.
The second area of focus has been extensive reading and research. As I make the transition from "weekend warrior" style fossil hobbyist to something more substantive, I have been consuming a large volume of academic literature on trilobites -- everything from studies on Isoteline hypostome function, biostratigraphy, ecdysis patterns, pathologies and predation, provincial faunalism, eye-blindness trends in evolutionary morphology, microsculpture variation, etc. I also managed to read through the entirety of the trilo-bible, "Treatise O" (the revised Kaesler volume of 1997, sadly not yet including the much-needed two other volumes to round out the rest of the taxonomic Orders). Courtesy of a trilobite worker's kind textual gifts and raiding my own university library, I am effectively training myself to be a subject matter expert on all things trilobite.
IN FOcus: Arkona
Before and after: excavation area #1 (January - October). End of season image does not do much justice to the work done as a lot of debris is already burying the work.
I have been tardy in photographing all the more recent finds from Arkona since my last post about it back in July or August, but there were a few more trips made where I made mostly similar finds as in previous trips this year. Excavation work was extensive this season (and, as I'm the human backhoe, my bar for what I consider extensive is fairly high!). Last season's work became entirely buried by several metres of overburden and debris after the usual processes of winter and the fall of the erosion-resistant widow-makers higher up in the Widder.
Effectively, we had to start from scratch. Pictured above was our first major multi-day foray to get a bite into the cliff from which we could clear out debris and extend benches. It took some doing to locate the productive trilobite layer given that the overburden was obscuring the visible facies, meaning we were flying a bit blind. At the point pictured above, we're still a bit high in the formation by about 1-1.5 metres. Not a bad guess, though, and we were able to work it down and across throughout the season, managing the usual issues of cross-bedding and complicated interlocking of the Widder.
The difference a month makes. In May, Malcolm unlocking new areas. In June from the same vantage point, during Roger's annual visit to Canada, the aftermath of much more removal. We finally hit pay dirt as some remarkable finds were being made at this point after about 7 combined days of clearing and slab hauling.
By the end of spring and into early summer, excavation site #1 is well over 2 metres high, 1-1.5 metres deep, and 10+ metres wide.
Many of us contributed time and muscle to dig this out, with most (solo) visits done by me given that I live the closest to the area and have more ready access. About 12 of us hammered away at this, with a dedicated core of about half of us making repeat visits. By summer, our first excavation was pretty much tapped out unless we wanted to repeat the long clearing process to dig in deeper, which would have meant having to work from the top. We then struck a new claim nearby to the east of the same exposure.
Excavation area #2 was a bit thinner on trilobite pulses. You can see the first area to the far left of Greg.
The slope below the excavation is littered with splits from previous visits. I was able to unlock everything to the right of Greg.
The extent of excavation area #2 just won't fit in a single photo. On this final day, I was able to clear out over 15+ metres to the east. Below the excavation, you can see the massive blocks of the encrinal Hungry Hollow Member. The Widder begins just atop of that and extends to the root of the trees above. The Widder is a strange (and sometimes frustrating) formation where certain faunal intervals repeat, including very dense brachiopod limestone, mushy shale, fossil-poor nodular calcareous shales, and stuff that just weathers to chips and nothingness with poor preservation due to underground water runoff.
In all, it was a substantive amount of focused work to get the site productive again, although I fully expect it to be completely buried by next spring, when the process will have to be started from scratch yet again.
A mostly pyritized and enrolled Greenops widderensis found on my very last trip to Arkona. I have a few rollers to prepare this winter, and such configuration does not lend itself to just basic preparation skills.
FINDS OF THE YEAR
As stated, collecting opportunities were not as plentiful this year due to site closures, weather, and scheduling conflicts. And, of course, the occasional injuries I would sustain from various physical activities. This year, rather than post my best according to taxonomy, some highlights of what made the year special. I am only including here the stuff that was collected, not purchased or acquired as gifts and trades.
Perhaps among my most scientifically significant finds would be this fragmentary cephalic fringe from Odontocephalus sp. found in the imported low-mid Devonian fill (Amherstberg - Bois Blanc - Dundee formations) of my backyard spot. Only a handful of fragments have been reported in the literature in terms of Ontario of a species that is more common in New York deposits. The last significant find of said fragments may be Stauffer's in 1915.
Not just one, but two examples of a new species for me from Bowmanville: Levicerarurus mammilloides. Specimen on the left was prepared by Kevin B., and I have the on the right in my preparation queue (the right eye is in the impression). This is an uncommon cheirurid initially identified by Bill Hessin in 1988, and is restricted to Bowmanville (Hiller Member of the Cobourg Formation). The first one was find in the May trip, and the second in the October trip.
Just a few samples of some placoderm pieces, some of which may be new to science (I still need to deposit them to the ROM along with previous years' finds). The middle one is certainly not new, but a typical placoderm armour plate from Protitanichthys.
This was more a bucket-list item for me. It took three trips to Bowmanville, but I finally found a full Isotelus mafritzae. This one is morph type 'A' due to the presence of the genal spine. I'm still in the process of preparing it, and will be restoring some missing shell. It is only slightly above average size for the species at almost perfectly 100 mm (sag.). I've not seen any specimens that also present such distinct muscle attachment scars on the axis.
Initially just a Greenops widderensis threesome, my friend Kevin's prep skills on my early summer Arkona find produced the surprise of a fourth one. All are enrolled in this gregarious assemblage. As these are body fossils rather than moults, it is likely they enrolled in response to a sudden catastrophic mudslide that effectively buried and smothered them.
Of the four new trilobite species found this year, this would be a short list:
* Odontocephalus sp. (?selenurus) - My thanks to both Scott M. and Dave Rudkin for confirming the ID.
* Leviceraurus mammilloides
* Thaleops sp.
* Flexicalymene croneisi
I was fortunate this year to make new field friends courtesy of their visits to my collecting localities, or to theirs. I was able to meet several new people from The Fossil Forum in person, and many others who are not on the Forum. I made new friends, and cultivated existing ones. In a niche passion such as ours, camaraderie is quickly established (and it helps that we can talk shop without our interlocutors becoming glaze-eyed!).
In the year since I took on a more serious approach to fossil preparation with specialized equipment, I've seen marked improvement in my skills, and I've had an embarrassment of riches in terms of getting guidance from veteran preparators. Some highlights of this year from my "lab":
Although the season has now dictated that I must down collecting tools, it means picking up the preparation tools while dreaming of what new and exciting opportunities for collecting may be in the offing for 2019.
I am reminded of one of Charles Southworth's statements about February, when we stop reminiscing about the collecting season that we've just had and start thinking about the season to come.
Looking ahead to 2019, there are already some new potential opportunities in central New York, in Ontario, and possibly even some digging when I visit Germany next summer. I am also hopeful that some of the sites that have been removed from our list this year will be available next year.
This blog will also not be taking a hiatus just because snow blankets the sites; I will be updating periodically as I acquire new specimens via purchase, and tackle my preparation piles. Stay tuned, and thanks for reading.