I spent four hours Monday at my nearby spot with the Amherstburg and Lucas Fm material, and likely split the last remaining viable rocks in the former that could potentially have bugs. The rest is pretty much stromatoporoidal Lucas Fm trash.
A really sad split. This would have been a fairly good sized Trypaulites sp. pygidium, but it just wasn't worth taking home. And so ends what was once a very productive location. I hoovered it well, draining it of its bugs. There may be some stragglers in some of the harder, more blank material, so it will remain my site of last resort. It lasted for well over 100 visits, and it has been very kind to me in giving up 7 different species of trilobite, 3 of which were new to my collection, and 2 of those being exceptionally rare lichids, and one dalmanitid that has never been reported in Ontario rocks. I never found anything complete, but I came close twice. The Devonian in Ontario is a big tease.
I'm fairly thorough and persistent, and so can say I've emptied two honey holes in my immediate vicinity. But a new one cropped up today. I've been meaning to have a look-see at this very large location for a while. It is certainly filled with layers upon layers of sand alternating with water-worn rock that spans the lower to middle Devonian, interspersed with lots of igneous and metamorphic gumbo. At a depth of about 300-500 feet, it is steady waves of glacial backwash. You'd likely have to dig a mile to hit bedrock in this town.
Devonian formations present include Bois Blanc, Onondaga, Dundee, and even some paper shale filled with Leiorhynchus that you find in the Hungry Hollow Member in Arkona. I started finding pretty sad Eldredgeops rana bits, but that was a sign of more to come. This was only meant to be a quick recon, but this place is massive and takes a while to traverse.
To the highlights, then...
This is the only E. rana I picked up and will show here. Why, because it's a roan red rana, that's why. This appeared in some Dundee material that is just littered with tiny red brachs all the way through, like the rock is infested with fat mites. The same process of mineralization that turned them red seemed to have worked its magic on this pygidium.
This battered bug bit is not even worth focusing the camera on. If, as my field comrade Kevin says, E. rana is the cockroach of the Devonian, Pseudodechenella may be a close contender for that title. Both of these have a very long stratigraphic range. No, I didn't take this one home.
Now this is where I get excited. Dalmanitids. These are not bad at all in terms of preservation, and possibly a bit better than how they come out in the material at my secret Onondaga spot. These both came out of the same rock. In fact, all the following Anchiopsis anchiops were found in it. This was truly a good rock that seemed to be a moulting ground.
The tails come paired with heads. The one on the left is sadly just an impression. The one on the right is likely complete, and I just need to do some cleaning and light scribing to reveal it in full. I've never found a full cephalon of this species before.
More bits and pieces.
No, it is not a fossilized chihuahua head, but an impendent hypostome belonging to Anchiopsis anchiops. This is the better of the two I found. This was a great rock. If I could find a lot more of it, I would be splitting all day.
And what is that pustular bit in the centre? Likely a Coronura bit, so make that species number four at this location.
So that was a nice three hours of exploring. I do plan on going back, of course, and it's nice to add another hot spot to the prospect list. I am hopeful my new backpack comes soon as I'm not sure if my current one will hold up for another adventure. Although my tactical pack is barely a year old, it is torn in a lot of places, and the straps have had to be tied and knotted to other hoops and loops several times. It doesn't help that I carry around about 30 or so pounds of tools in it, and then add another 20 pounds of rock. The thing was bulging at the seams, threatening to burst. Not what you want to have happen in the field, far away from home.
Site knowledge: it's a Devonian buffet. There is no sense in creating a trilobite list associated with the stratigraphy because the rocks are transport erratics from all over.
In other fossil news, I have created a fantastic prospecting field document for Silurian trilobites of Ontario, and am eager to get on the road to trial its effectiveness. Obviously I won't post that here unless my goal was to ensure others would scoop up everything first. But, a few of my field comrades will hopefully benefit.
Tomorrow looks like a rainy, ice-pellety day. A good one to do a bit of prep. On Friday it is back to my secret Bois Blanc spot to do a whole day's work. Stay tuned!
So I've returned numerous times to my new spot, but have not had the same level of success as my first two outings. I now have a ludicrous amount of Crassiproetus pygidia, but nothing complete and not even a whisper of another Terataspis. If all this material is indeed Bois Blanc Formation, I do find it curious that I haven't yet encountered even a tiny fragment of the dalmanitid Anchiopsis anchiops, which is fairly abundant in that formation. That may be attributable to the specific paleoenvironment in which these were deposited, just as one may encounter trout in one part of a river, but not in a smaller river nearby.
I've been able to identify six distinct types of rock at the site, with only one of those being trilobite bearing. I'll be giving the spot a bit of a rest for the time being while I focus on other projects (and get back to teaching).
I've two illustrations -- one complete, and the other in process -- that I can reveal in the next while. For now, I want to discuss this:
Seasoned trilobite collectors in Ontario are very familiar with this text, a veritable bible put together by the masterful Rolf Ludvigsen who passed away in December, 2016. He was an intellectual giant, a taskmaster, and an exacting top tier scholar. This book was published in 1979, and a lot has changed in Ontario trilobite knowledge since then: the genus Phacops in North America was reassigned to Eldredgeops, the great Bill Hessin formally described the cheirurid Leviceraurus mammiloides, Lieberman and Kloc reassigned Neometacanthus to Bellacartwrightia jennyae, and even humble amateurs like myself have put in tireless efforts in finding some trilobites that haven't been reported in over a century.
The state of fossil collecting in Ontario is mixed. With more site closures, places getting tapped out, suburban sprawl, areas now under provincial park designation, and other issues all too common in many parts of the world, the halcyon days are certainly over. Of course, the undaunted die-hards like myself will continue trying to locate new spots, to dig deeper and farther in unlikely locations, even if they are small and quickly exhausted.
I do think it is time to honour Ludvigsen's project in revising this text. Of course, that is a matter of expertise, time, and money. There is not a tremendous amount of research interest in such a niche project. That being said, some small and remarkable steps have already been taken. For example, Philip Isotalo's book on Ordovician trilobites of Ontario is exactly the kind of enterprise that we need more of. Bill Hessin's invaluable field guide to southern Ontario fossils has also quickly become a kind of bible for collectors in the GTA and surrounds.
There is still so much more work to do, and sometimes I regret not specializing in this field when I entered university. We still do not have a formal description of the Cobourg Fm Isotelus "mafritzae", which should be a top priority housekeeping item.
I can only do so much on my own given my limitations. I'm not a paleontologist, I do not have access to the granting structure. What I do have is the passion and energy. If someone reached out to me and asked if I wanted to play even a tiny role in revising Ludvigsen's text, I would very much take to it like a duck to water.
So, to that end, I've been combing through the literature to create a kind of "master list" of Devonian bugs in Ontario. There are plenty of known unknowns. There are species that should technically be found here by stratigraphic correlation, but have not been confirmed. I'm providing my list, a work in progress. I've been fortunate (and stubborn enough) to find examples of 15 of the roughly 25 species found in Ontario. If you are a trilobite worker in Ontario reading this, I'm more than willing to put in the work needed to revise the Ludvigsen text. We've already seen the resurrection of another of Rolf's projects courtesy of Fred Sundberg in the form of the rebooted Trilobite Papers.
It is a major ask for a major task, especially when we have yet to even see the second volume of the Treatise! But there are so many tireless trilobite workers out there today whose efforts are on par with the greats of yesteryear, such as Jonathan Adrain, Gerd Geyer, Richard Fortey, Joan Corbacho, Gerald Kloc -- just to name a few.
So here is my list so far. My thanks to the indefatigable efforts of Scott Morrison as the true trilo-lit archivist par excellence for putting key documents in my hand. I hope this list assists our collectors -- professional and avocational.
Pseudodechenella ?rowi / ?arkonensis
Widder (Hungry Hollow)
Eldredgeops iowensis southworthi
Crassiproetus sibleyensis* (corr. Michigan)
Pseudodechenella nodosa* (corr. Ohio)
Odontocephalus selenurus (?)
Coniproetus folliceps (corr. NY)