I've only managed to get out once in the last week to a local spot that exposes London's "strata" -- And by that I mean the vast depths of glacial overburden when all of this was once Lake London 13,000 years ago before it burst spewing more than five times the force of Niagara Falls, and emptying out in a matter of days. The nearby ski hill, for instance, is not imported riprap, but glacial erratics transported by the force of rushing waters.
Anyhow, no real keepers on this visit. The material is a mixed Devonian salad that extends from the Hamilton Group down to the Bois Blanc Formation.
These are all Anchiopsis anchiops pygidia from this location. What is interesting is that these appear in three distinct lithologies.
I also spent some time between grading papers in the lab.
This is a one inch / 2.5 cm baby Isotelus from Bowmanville I picked up about a year and a half ago just in case the urge struck me to do some resto with Milliput. I decided to give it a go. As can be seen, a lot of the trilobite was missing. Since it is very small, and I have big mitts with not the best carving tools, it didn't go as well as I would have liked...But I can actually fix this by smoothing out a few portions (with some fine grit sandpaper and very light abrasion) and ever so slightly downsizing the eyes, which actually turned out the shape I wanted them to be.
Okay, what's next? A before and after of a Ceraurus pleurexanthemus I found in the Neuville Formation on my recent trip to Quebec.
Both genals, tail spines, and eyes are present. There were some issues with a hard calcitic crust, but I was able to dolomite my troubles away. All that remains is some very careful matrix landscaping to make it pop. The photo does little justice to it, mostly on account of the finished product still being a bit dusty and damp. But here's a more dramatic shot:
The cephalon tucks down a bit, but I think it is a pretty decent prone. It is not easy finding these without something missing, like an eye or tail spine... or just finding bits and pieces forever.
It's been a rainy autumn so far, which puts a damper on getting out in the field. So, why not warm up the tools?
I started out with one piece with three trilobites on it, a combination flip and stabilization job. The shale is very brittle with numerous hidden fractures... and the pieces were not snug enough for the gluing, and there wasn't much of a way of fastening them together with the vice clamps without breaking the shale. Suffice it to say, it was an unmitigated disaster... but one I can fix later when I have the patience to give it another go. It wasn't the best of my ideas to take on a complex job right away!
I am performing a flip job on a ventral, and waiting for the matrix-paste I ground up to cure. That I'll save for another post.
Let's get to the low hanging fruit.
This is a Gravicalymene sp. I found in the Nicolet Fm in the Montreal area. Sadly, it was already exposed and missing some shell. Still, I made the best of it. I could tinker with it a bit more, of course. This is soft shale that takes well to baking soda abrasion. I didn't once have to take out the scribe for this one.
This is a giant, inflated Eldredgeops rana that I found not far from my house, in a particular horizon of the Dundee Fm that is cherty and breaks in chunks -- many times right through fossils. My collecting friend and expert preparator advised me to be very careful with this one since, well, how many Dundee Fm Eldredgeops rana have people found? Unlike the same species in the Windom shales of Penn Dixie, this one is not small or partially flattened. But, as can be seen, it is missing some shell and requires a bit of resto.
Preparation in this rock is hardly simple. This specimen needed considerable stabilization even before even thinking about scribing. I used the ME-9100 to remove the big chunks of matrix, always careful to control any transferred vibration that would cause the rock to break apart in an inconvenient spot. I swapped between a Pferd and full dolomite abrasion for the rest.
This was a tricky bug, including some fractured mess at the top of the glabella, and the shell is both relatively thick but also very fragile.. Still, a plump and healthy specimen measuring 50 mm (2 inches), or 60 mm (2.5 inches) if completely outstretched.
It would look even better if I landscape the matrix more, but I can't seem to master that skill yet.
This weekend I was able to get back to my Dundee Formation spot in Oxford County. The site is not quite perfect to permit full access yet, but in a few weeks (and early spring) will open up more of the rocks. It should be stated that these are brutally hard rocks that will shatter -- or the bones of the person who hammers these may shatter! This is why part of the excursion requires selecting the right rocks where natural forces have made them slightly more fissile for splitting. The fossils generally appear silicified, much akin to the Amherstburg Fm material I also collect from.
Nothing amazing, but it was an interesting visit.
I have already shown what the matrix is like in a post back in April, so I'll just show some of the things I picked up. Brachiopods are, by far, the most conspicuous and numerous fossils to be found in the platy layers, followed by abundant rostroconchs. Not only that, but the brachiopods could attain very plump and robust sizes as pictured above. There is an incredible diversity of them unmatched in most Devonian strata in Ontario. The brachiopod on the lower left is quite a looker, full detailed, free of matrix and with both valves.
A calcified gastropod that looked sparkly in the sun at the upper left. And, of course, obligatory rostroconchs that I would put in my pocket if they came free of the matrix. I did keep one in matrix with a buddy brachiopod to function as an association piece should I donate a number of these to a museum.
On to the trilobites. Most of the species in this horizon were encountered, including countless Pseudodechenella sp. parts I tend to pass over. I do make an exception for these Odontocephalus sp. given that they are very likely a new species, which means collecting as many samples as possible. They were not as numerous today, and there were some fragments of denticle cephalic margin I didn't bother collecting, as well as some pygidia that were too busted to be of much use. Instead, my goal was to collect fragments that had much clearer diagnostic details, and particularly the morphological trait that would assist in describing this as a new species: the forked pygidial spine.
Compared to previous visits, the giant dalmanitid, Coronura aspectans, was particularly abundant -- in fragments only, of course. In most cases it would be the presence of a single thoracic segment. The piece with the most promise would be the one on the bottom where a good portion is buried in the matrix and awaiting my prep tools.
The photos do no justice to these partials. This again is a Coronura pygidium, much of it buried in both the positive and impression side. Some prep will be needed.
In all, a fair outing. The deposition conditions were turbulent, which rarely ever bodes well for finding complete trilobites, but it is a possibility. I am fairly confident that it is just a matter of time and repeat visits that I may come upon a complete one. A complete Coronura would be an incredible coup, but a full Odontocephalus would be invaluable to science.
Yesterday was a perfect day to be out. Not only was it national fossil day (at least in the US, but I suppose we can extend that more internationally), but it was in mid-teens, and a good mix of sun and cloud. I made my way to the local Amherstburg/Lucas Fm spot with no real expectation of finding much of anything at all given that I've made so many visits as to deplete its more gainful rocks. I can't say that this trip provided me with glorious finds, but it was a fair outing.
I neglected to take a picture of the armour stone I was dealing with. Let us just say that it was big, heavy, and very dense. How dense? I had scored the sides at multiple locations for getting in the chisel, which I was able to sink by a good two inches at each spot without so much as causing a crack -- just tons of rock powder. But, with a couple hundred more blows moving from hole to hole, a hairline crack emerged, and another hundred blows split the beast in two. It is simply the stubborn nature of many Devonian rock formations in Ontario to be brutally hard, with a tendency to shatter rather than split, which makes collecting specimens an added challenge.
Occasionally, these long bryozoans appear, and nearly all of the representatives of this species are mineral stained a deep ochre.
I found a few poorly preserved pygidium fragments of Acanthopyge contusa. Due to the silicification, the negative (on the right) are far clearer than the positive to show diagnostic details.
More of the same.
Pseudodechenlla sp. parts are widespread throughout the "layers," including isolated cheeks and pygidia. I suspect this may be one of the poorer examples, or possibly a Trypaulites. On the right is a partially buried Crassiproetus in a typically busy hash.
Thoracic segments are not entirely common in this material, as it seems to favour fragments of cephalons and generally complete pygidia. The size and width of these segments suggests Crassiproetus crassimarginatus. The pair on the right -- "fat man and little boy" -- are also the same species.
The two rarest to be found include a pygidium of Mystrocephala stummi, and a partially buried and poorly preserved Echinolichas sp. At this point, I probably have about six examples of this incredibly rare lichid not reported in Ontario rocks.
It would be a fool's errand to assume complete trilobites will ever be found in this material given the depositional conditions, and so one must be content with fragments. It is an interesting lithology which also gives off a kind of petroliferous odour. Unless I start flipping more rocks in the pile at random in the hopes of locating more rocks of this specific horizon, I may have tapped this location out. It has been since late August of 2019 that I have made repeated visits here, and I have performed due diligence in collecting almost every lichid fragment and most intact rare species fragments (Mystrocephala, Trypaulites), if not a few almost complete Pseudodechenella and plump Crassiproetus pygidia. Many of these will likely form part of a museum donation at some point.
This was a nice way to spend national fossil day. Although the finds were not showstoppers, I can be content that I bumped into examples of just about every species that can be found in this material, and they all emerged from one single armour stone that took a number of hours to break down.
Earlier in September, I was across the provincial border for a weeklong fossil dig -- and it was quite good timing indeed as it would not be long after that when both Montreal and Quebec City were escalated to "red" zones due to Covid. Fortunately, fossil hunting is already a socially distanced activity. Still, I was able to isolate upon my return.
It was a fairly productive trip. Due to obvious reasons, I will not be posting specific sites in name or in photos, nor some select finds I'd prefer to keep private. I will leave this somewhat circumspect to say that I collected in the Neuville and Nicolet Formations (both Upper Ordovician), which covers a fairly broad geographic stretch. In all, I came back with a healthy number of trilobites, crinoids, and other interesting items. It takes a lot of work and a lot of shorelines.
My immediate pre-trip, pre-scruffy self. The view from the train on the long travel day. Montreal skyline by the evening. One of the highlights of this trip was to pay a visit to Mario who curates the Musée de paléontologie et de l'évolution. A fabulous and drool-worthy evening was had in viewing just a small selection of the over 70,000 catalogued specimens, drawn from the donations of the best collections in both Quebec and Ontario. There is just too much to post and comment on individually, so here's a slideshow. Prepare for eye candy:
As for my own finds, I would class them as very good for me, a visitor, but fairly typical and common for those who collect in the Neuville and Nicolet Formations. Just about any shoreline will have something to offer, but one has to work at it to get anything half decent (fairly standard in most fossil-bearing areas).
I'm going to be lazy and not caption everything above, but a typical array of fauna from a few carpoids, crinoids (Ectenocrinus and Cincinnaticrinus), a conularid, bivalves galore, and my favourite, trilobites (examples of Ceraurus pleurexanthemus, Flexicalymene senaria, Cryptolithus tesselatus, Gravicalymene sp., Isotelus gigas, Triarthrus rougensis). The big Triarthrus glabella might belong to a T. beckii, but there isn't enough diagnostic material preserved for me to make that call. Oh, and that lovely book was courtesy of the author himself, whom we met briefly (socially distanced!) in Kingston, en route to Montreal (Thanks again, Phil!).
This was how my fossil trip kind of began, finding this Bathyurus superbus in a dump pile in Kingston. It was a good omen, if not another checklist trilobite in my collection. It will need some serious prep of what is left of it. Speaking of, I dabbled a bit with my current batch of finds,
Two Ectenocrinus crowns surrounded by a lot of stem action. This is just a start, and practice as I don't generally prep crinoids.
Work in progress on this Ceraurus pleurexanthemus. I'm still trying to fish out the right eye and genal, which is currently under a very tough calcitic crust.
So that is about it. A pretty OK trip, and my first time digging in PQ despite having gone so many times (in that interval between my post- and pre-fossil days). So now, due to Covid restrictions, any digs I do will be much more local. This has already been a fantastic collecting year for me, so even if things start winding down I have no regrets... and tons of stuff to prep and draw.
And this just in: a Cybeloides plana from the Bobcaygeon Fm in the Ottawa area.
This will be a relatively short post as I begin gearing up for another multi-day adventure out of province.
As I wait on a few more regional spots, I made a casual return visit to a local spot that is a Devonian salad of southwestern Ontario formations. The only notable trilobite find was a pygidium of Trypaulites calypso. Ludvigsen (1979) tells us that this species is not reported in Ontario rocks, but does appear in correlative strata in both Michigan and New York, which is to say it occupied both basins.
I performed some preliminary scribing just enough to ensure that the diagnostic details would square with the certainty of proper identification. I have found quite a number of this species in Amherstburg and Dundee Formations, but the nature of the preservation has generally meant that they were either silicified or appearing as a steinkern. In this instance, the ornamentation is clearly visible. One of the key diagnostic traits of this species would be the backward-facing axial nodes that lends it a kind of sagittal ridge appearance, in addition to the number of pygidial pleurae, which has a variability of between 10-14 (see Lesperance, 1975).
A focused image-stacked photo reveals the very fine granules on the shell. It is fortunate that this was preserved in such good condition, as many of the recorded examples do lack the detailed prosopon. This is not by far a tremendously exciting find, but certainly of interest for its detail.
But this is just the beginning of the end of the season, and autumn is the ideal time to kick it up a notch due to the cooler temperatures. I've already been fortunate this year in having made two extended trips far from home, and I can safely say that this has been the very best collecting year so far despite the ever narrowing prospects for fossil collecting in Ontario. It has taken a lot of diligence and sweat, but I think I may have graduated to "serious and dedicated collector" as opposed to "weekend warrior." The efforts, although not all gainful, have certainly paid off. Stay tuned for what the remainder of this season may bring!
UPDATE: Just a quick and neat find today barely a few minutes' drive from my house, amongst river transport rocks, all Dundee Fm. I made a run to the hardware store to replace a missing brick hammer, and it was the last one in stock. I checked out a new, very small, spot that would only take a few hours to exhaust. Breaking in the new hammer, after no more than ten minutes, a full prone Eldredgeops rana that will measure about 50 mm when prepared was staring up at me from a fresh split. Sadly, some of the shell is missing or stuck to the impression (which I kept), but I can do some light restoration with Milliput.
A pretty robust one! I seem to be able to find trilobites anywhere.
And this just landed in the post on the eve of my journey to la belle province. It was listed as Mucronaspis zagoraensis, but on account of the blunted genal spines I was leaning toward this actually being Dalmanitina socialis, which is also found in the Ktaoua Fm in Morocco. This was later confirmed by my friend and trilobite expert, SM (my thanks!). It's an internal mould, and about 7 cm long with the caudal spine in place, with just a bit of crush damage on the left side of the cephalon, missing an eye.
I've just returned from an almost week-long adventure to Manitoulin Island and surrounding areas. Three of us prospected numerous sites harvested from old literature, word of mouth, and satellite imagery, including a large number of road cuts, ditches, and piles. Most of our more productive and interesting finds came out of the Bobcaygeon Formation, north of Manitoulin, whereas many other sites were the wrong material, tapped out, overgrown, or far too weathered.
In an effort to be circumspect about locations, no site pictures will be presented here -- only typical material and finds. I will cluster these slideshow style by site, with descriptive captions. Not all sites that we prospected will be presented here.
Site #1 - Bobcaygeon FM upper interval
Site 1 was an upper interval of the Bobcaygeon Formation. Much of the Ordovician material around the Manitoulin area occurred in relatively near-shore environments (save for during Whitby/Collingwood time), and are all high energy. This means many of the specimens have been heavily disarticulated.
Site #2 - bobcaygeon fm middle and upper interval
This site contained the middle and upper portions of the Bobcaygeon exposures of the area, and was by far the most productive for trilobite diversity.
SITE #3 gull river fm (?)
This was a cut that has since weathered too much and become overgrown. Most of the horizons were blank.
SITE #4 - ordovician - silurian boundary
Our search for eurypterids in the Ordovician-Silurian contact was not productive beyond finding numerous algal material.
Site #5 - manitoulin fm
The dolostones of this formation contained nothing other than numerous corals and brachiopods.
site #6 - Whitby/collingwood
Locating some Whitby shale, much of it was very dense and largely blank. No traces of trilobites were found.
This site was an aggregate of material from local roadcuts, with some variability of lithology. We were able to map it against a nearby road cut that was quite tall and had representation of every rock type we found in the pile. This was also the spot where the two trip-makers were found.
Overall, this was a long and exciting adventure with two incredible field comrades. There were certainly more misses than hits in our prospecting, but the occasional stellar finds made up for some of the frustration and disappointment. It was no less thrilling for me to find examples of ten new species for my Ontario collection:
Bathyurus (Raymondites) sp.
I'll tie up this blog post with two trilobites that were waiting for me on my arrival home:
I'll be heading up north on a big dig at numerous locations. Today I was able to get out to my Amherstburg/Lucas Fms spot with a focus on Lucas Fm. Why? The Lucas is pretty blank, crystalline, or riddled with nothing but Eridophyllum-esque corals and domic stromatoporoids with a dash of tiny rostroconchs or Amphipora brachs. The sandier layers contain rostroconchs and poorly preserved low-spired gastropod steinkerns. My goal was to perform due diligence as I start filling in the chapter in my Devonian trilobite guide on the Lucas.
Well, the Lucas was not lucky today. Instead, I became distracted with some Amherstburg blocs. Not too much to show, but some lichid pieces.
This is the positive and impression of a lichid fragment with the telltale tubercles. The positive side is almost impossible to make out.
Hypostomes. These are all the same size (about 7 mm wide). The one on the left would likely belong to Acanthopyge contusa on account of how the "divots" are spaced apart, whereas the positive and negative specimen on the right looks more a fit for Echinolichas sp. as the divots are closer together. Again, nothing complete (and likely nothing ever will be in this material), but I think I have more Ontario Devonian lichid material than just about anyone!
Nothing all that exciting or new, but a nice send-off before it's 5-10 days up north to dig into some Ordovician and Silurian material. If I can't come back with fossil riches, I'll at least come back with good memories breaking rock with a great field comrade. Until then...
I spent the last two days in the field, prospecting about nine different spots and coming up fairly empty-handed. I'll chalk this up to practice, and performing due diligence in crossing off possible locations to better identify the productive ones.
The first day was close to home, mostly sifting through glacial erratics.
These would be a positive and negative of a poorly preserved pygidium in Amherstburg Fm material (and the thinly-bedded, bituminous, crumbly, trilo-poor stuff). Judging by size and other morphological clues, I would label this a Trypaulites sp.
The remainder of the day morphed into a challenging three hour hike in the woods, so not much by way of further fossil opportunities for the day.
On the second day, Deb and I met up with our dear field comrade to inspect about seven prospective spots beginning with an outcrop section of the Dundee Fm listed in a relatively recent dissertation, and then to the lower Devonian Bois Blanc Fm, and finally to a number of Silurian locations around the Niagara region. I am not one to post location photos anymore for obvious reasons, but it would be hard to place this location and it really doesn't have much to make going back there worthwhile as it is mostly just reefal madness. This is Dundee Fm, and it had absolutely nothing but coral and a few bryozoa. Not even brachiopods.
That is a single coral with likely a second branching off it. The length extends to the full frame of the first image.
This location is all Bois Blanc Fm, but sadly not the right horizon. In terms of biodiversity, a single brachiopod was found, and two scarce gastropods; everything else was entirely reefal material of corals, crinoids, and bryozoa.
Case in point would be these hashes. There is virtually nothing here but the coral, crinoid, and bryozoa salad here.
And let's not forget giant coral colonies.
The Niagara region is filled with likely hundreds of creeks vermiculating across its landscape. This is one of them. The strata on the right is quite distinct, and not gradational. The yellowish dolostone is likely Lockport Fm.
A giant millipede. We did find a good chunk of Rochester shale, but it was entirely blank, and not even the hard-ground limestone lenses had any fossils. This stuff would be brutal to try and work with, as it is wet and just weathers out as chips -- a bit like some intervals in the upper Widder Fm.
This would mark my second big attempt to find anything of interest in the Silurian of Ontario. I've covered a good stretch of it in the north (Bruce Peninsula area) and now the south (Niagara), and have yet to hit proverbial pay dirt. In this recent trip, we covered about 500 km and did not prosper. To my disappointment, I have yet to collect a single fragment of Silurian trilobite from Ontario despite a great deal of research and effort. Perhaps the Silurian is a cursed geological period for me! We do have to keep in mind that just about over half of the Silurian exposed in a narrow band in Ontario from St Catherines up though Tobermory is Salina and Bass Islands -- both unfossiliferous units when this part of the world was salty sabkha. Of the other half that are fossiliferous units, about half or more of those were very poor preservation conditions, and the other half is generally inaccessible. I may just have to cheekily rename the Silurian formations in Ontario along the lines of "and here we have the Bugger All Formation, which lies conformably over the Utter Crap Formation, and contains the Nada, Bupkis, and Blank Members."
I will leave the Silurian alone for a bit and refocus on the Devonian and possibly the Ordovician as early as next week.
It's been a bit of a fossil famine as of late. The heat has been pretty fiercely oppressive, but it has been more the issue of not having much collecting opportunities on account of sites that are tapped out, temporarily or permanently inaccessible, and the need to prepare for the upcoming school year by pre-recording a monstrous amount of lecture content. But it is also a dry spell I hope to break in the coming days and weeks.
For now, a few minor trilobitic items just to keep the blog warm.
A fairly sad ensemble, but these were pretty much all that was to be found at my Devonian salad location. Upper left is likely a ventral cephalic fragment of an Anchiopsis anchiops, and the lower left is a busted butt of a Burtonops cristata. I may have effectively drained the site of its riches. These samples above were not worth taking home.
A snapshot of a section of my Amherstburg/Lucas Formations fill area near my home. This would be the area I would concentrate on, with understandably low expectations given how hard and often I've hit this place since I bumped into it last August.
The productive rocks are scarce at this point. Above we see the typical proetids of the Amherstburg: Pseudechnella sp. and Crassiproetus crassimarginatus.
This is culled from two of the productive rocks. Nothing I don't already have numerous examples of. Top row is Crassiproetus crassimarginatus, second row is an unknown, a Trypaulites sp., and a Mystrocephala stummi. Third row is a big Crassi, another Mystro, and some disarticulated Crassi thoracic segments. Bottom row is Mystrocephala stummi, Pseudechenella sp. Acanthopyge contusa. At least I found a lichid bit.
This was a purchase from a forum friend. An effectively complete, albeit somewhat roughed up, Odontocephalus aegeria from the Needmore shale of Pennsylvania. Given my excitement over the genus after locating fragmentary specimens here in Ontario, I was hankering for a complete one to function as a kind of lucky charm for when my Moorehouse Member site becomes accessible again, once the water levels drop.
I have two more trilobites coming from the Purchase Formation, so to speak, but right now the operative focus is on getting back out there, and prospecting new sites. Fingers crossed that this blog doesn't go into another prolonged radio silence!