Deb dropped me off at my little hidey-hole near Thedford. She would have joined me, but it was far too hot: about 30 C, but pushing 40 C with the humidity and heat bouncing off the rock. But I kept well hydrated and moved a lot of rock to find some modest Widder Fm treasures. About 6 hours of slabbing and splitting leaving me a bit sore at the end. Thankfully, I took just enough water to keep me hydrated.
Spirifers are very common here, and can come to dominate certain layers. It functions to tell me where I am in the Widder, as it is a game of inches. If there are plenty of spirifers, I am either too high or too low from the productive trilobite layer. Thousands of these can be had, and many of them pop out of the rock easily. I snapped a picture of this one as it was fairly large.
Clusters such as these are also present. They don't pop out as cleanly, though.
Spirifers with the long wing tips are slightly more uncommon, but not rare. What is rare, however, is them appearing intact because the tips are very delicate. This one I had to keep.
Cephalopods. On the left is a pyritized nautiloid that could use a bit of clean-up; to the right, a Tornoceras with a lovely pyrite sheen. On occasion they can come out inflated, but this one is pretty flattened.
Trilobite moults of Greenops widderensis are very common. Hundreds of cephalon and pygidium fragments are scattered throughout the layers. In this case, whenever you see a thorax, there is a higher probability that it is complete. Sadly, this one is missing half its tail shell so I left it behind.
Next to the bivalve is another possibly complete trilobite buried in matrix, but missing its right eye. The shell is very thin and delicate, and the nature of the shale does not regularly split along bedding planes. They only rarely come out fully exposed, and more commonly (in the uncommon event of finding a full prone!) appear partially buried or dividing its shell between the positive and negative halves. Not always the best laminations!
The real purpose of my trip is to bag full trilobites. This one is partially buried in matrix, and I'll likely update this post once I have a chance to prep it out. It is complete... except for just a tiny bit of genal spine missing on its left side. And it is very small (about 1.5 cm). This would be my find of the day.
I took a break by the water where there are some outcrops of Hungry Hollow Member. Peering right back at me was this beat up Eldredgeops rana roller. Pity it isn't in good shape, but the rollers are not always the easiest to find here.
Fiddling a bit in the Hungry Hollow Members, I didn't find much else. This image is simply to indicate just how dominated by corals this Member can be. As I have enough coral, I didn't bother taking it home. I hope to go back this weekend and have another go looking for more trilobites. Until then!
Spent the day at the biannual Bowmanville dig at St Marys Cement quarry. Sadly, it seemed that wherever the real gems were to be found, I was not there or others found them first. It wasn't all disappointment, but it felt a bit demoralizing to come away with not the greatest stuff given how much I scanned and split.
Here I am in the parking lot before the dig began. This is a working quarry (even on Sundays), and full safety gear is mandatory. Once everyone is suited up, we go to the office, sign our waivers, and listen carefully to the safety procedures as told to us by the pit boss.
This is a vast quarry with six levels. Depth of field illusion here does not convey the size of this place, nor the blast piles that can rise several storeys.
While a few others were finding full Isotelus trilobites, I kept coming up with moulted fragments. This piece here is a partial ventral side of a cephalon, so if it were full it would be fairly large.
Large Isotelus tail pieces.
Small Isotelus pygidium and thorax. It might be complete, but enrolled. Some air scribe action may confirm it, and I'll post an update if it is complete. UPDATE: it is not complete.
A possible Leviceraurus mammiloides, but waiting to hear back on ID. This is after I prepped it a bit. In the field, only the thorax and part of the pygidium was showing. Unfortunately, it is missing any long tail spikes.
Weathered to the point of hardly being recognizable, a Ceraurus sp.
Other bits from the Lindsay Fm. A Calyptaulax cephalon, a busted Isotelus roller, and something I haven't figured out below that.
Could be Isotelus, but not quite sure yet.
By about 1:30, we retreated to the top level to split large books of Whitby shale. There's not a lot of diversity in the shale in terms of trilobites (Pseudogygites and Triarthrus, which usually only appear as disarticulated moults). But this was an oddball piece, and somewhat uncommon. There is some disagreement as to whether this is a cephalopod or a gastropod. UPDATE: it is a cephalopod, and a rare one: Trocholites ammonius.
Pseudogygites latimarginatus. I kept it because there was a chance it might be complete. After some work to remove the covering shale, I was disappointed it wasn't. Someone else found a full one that was a whopper of a size at about 6ish cm.
He left the impression, so I took it as a consolation prize.
Pseudogygites latimarginatus, mangled.
Typical hash plates from the Whitby shale.
In all, a pretty poor showing by my standards. It's been a while since I've been skunked like this, made doubly disappointing when we can only gain access twice a year. Here's hoping the next trip is much better. If I do have a Leviceraurus, then at least that would be a new species in my collection.
With the long weekend in full swing, I decided to get up early and have a look at the pit/pond just beyond my backyard. Much of it is Bois Blanc and Dundee Fm fill. I've made a lot of posts about the area in the last five years. This time around, I found something new.
I spent some time in a 10 m x 10 m area by the pond, breaking whatever looked promising. I've found some interesting gastropod steinkerns in the past, and this one was no exception.
Trilobite partials to the left, a brachiopod on the right. Typical fare for these lower to mid Devonian rocks.
A nice split with a little bit of everything - mostly brachiopods and one horn coral calyx (the round item).
A high-spired gastropod steinkern (partially buried in matrix) with its impression.
Closeup of a bryozoan.
More trilobite partials (two pygidia impressions and one cephalon impression fragment)
Eldredgeops sp. cephalon fragment.
Believe it or not, this was the major find of the trip. Although it is only about 2.5 cm wide and kind of looks like it could be a fragment of coral, it is indeed a trilobite fragment... but which one?
I also ensured to collect the negative as well. It is a good idea, when in doubt about a specimen, to collect it - and all the other pieces it is associated with!
So to which trilobite does this "toothy" fragment belong? Courtesy of our resident trilobite expert Scott, on The Fossil Forum, the answer can be found here:
Stauffer, C.R. 1915
The Devonian of Southwestern Ontario.
Geological Survey of Canada Memoir, 34:1-341
It is Odontocephalus sp. and as Scott tells me, in the last century or more, this trilobite has only been reported in a few papers from Ontario, thus making this a far from common find! Pictured below is a simplified line illustration of what it looks like complete.
So... that's quite exciting! This site has now yielded up the following trilobites in the last few years:
Odontocephalus sp. (?selenurus)
This figure from Lesperance and Bourque (1971) shows the evolutionary branching from the genus Roncellia. My recent find means that I have representatives of each of the three major synphoriinae branches (Odontocephalus branch, Anchiopsis branch, and Trypaulites branch). What distinguishes them significantly is both the anterior glabellar process/border, but also the pygidial "spike" (or lack thereof). Note here the bifid spine that appears in both Odontocephalus and Coronura.
At this point, I am a bit more confident in assigning this one to the species of O. selenurus given the presence of 9 rather than 11 glabellar denticles as would be found on O. aegeria (which is also not reported to be found outside New York).
According to Stumm (1954), only three fragments of O. selenurus have ever been found in Ontario; the first, by Carl Rominger in 1888, and two by Stauffer in 1915. Assuming no further fragments have since been found, my find would be the first in 103 years, and the fourth in Ontario's paleontological history. This makes this find quite exceptional and rare!
This particular species is cited only a few times, including in Stauffer (1915), Stumm (1954), Lesperance and Bourque (1971), Lesperance (1975), Sanford and Norris (1975), and Ludvigsen (1979).
1. Lesperance, P. (1975) Stratigraphy and Paleopntology of the Syphoriidae (Lower and Middle Devonian Dalmanitacean Trilobites). Journal of Paleontology 49.1: 91-137
2. Lesperance, P. and P.A. Bourque (1971). The Syphoriinae: An Evolutionary Pattern of Lower and Middle Devonian Trilobites. Journal of Paleontology 45.2: 182-208.
3. Ludvigsen, R. Fossils of Ontario: The Trilobites. ROM.
4. Sanford, R.V. and A.W. Norris. (1975). Devonian stratigraphy of the Hudson Platform. Geological Survey of Canada, Memoir 379 I. 1-124; II. 1-248
5. Stumm, E.C. (1954). Lower Middle Devonian Phacopid Trilobites from Michigan, Southwestern Ontario, and the Ohio Valley. Contributions from the Museum of Paleontology, University of Michigan XI.11: 201-21.
6. Stauffer, C.R. (1915). The Devonian of Southwestern Ontario. Geological Survey of Canada Memoir, 34:1-341
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:
DAY 1: Penn Dixie
Returned Monday evening from four fabulous days swinging hammers, slabbing and splitting in the field. We managed to hit two sites, with plans for a third site falling through due to weather and site conditions.
We left home on the Friday morning to arrive at Penn Dixie, in Hamburg/Blasdell NY (south of Buffalo) by noon time. It was not a public collecting day at the site, but members of the Hamburg Natural History Society are permitted to enter the site.
A group of us digging through some fresh material
Of particular note was just how much PD had changed since last season, and that is due almost entirely to some well-directed excavations at some key spots to reveal more of the Smokes Creek trilobite layer, but also opening up other on-site locations such as the Bayview brach layer and the North Evans limestone. We had the excavator on site for the second day, with the previous day ripping up a new spot in preparation for the annual Dig with the Experts event. We did not touch those piles, and focused on other spots.
I found this piece of Devonian wood, and it is a fairly healthy size for this location.
One of the excavated spots we spent the most time working on was fairly thin on trilobites, which suggests that they appear in deposition pulses on the seabed. There's no way knowing in advance if there will be a lot of trilobites, and so you hope to hit paydirt by attacking the Smokes Creek layer.
A fairly large Goniatite, sadly all busted up.
Later in the day, we migrated to a new gully area where some of our other collectors on the Sunday previous had found a few examples of the rare Bellacartwrightia whiteleyi trilobite. Sadly, that lead dried up and no Bellas were found. For the most part, trilobites were mostly appearing as disarticulated bits and moults, with not much in the way of assemblages or complete prones and rollers.
Full prone, but containing shell on both sides of the rock. This will need to be glued together and prepared.
I did have some luck despite the parsimonious nature of the slabs we were splitting. However, the "trilo-bonanza" was still eluding us all. A little before sunset we decided to leave and check in to our motel, grab some pub food, and rest up for day 2 of our trip.
DAY 2: Deep Springs Road
At around 6 am the next morning, our friend Jay picked us up at the motel to begin our first ever trip to Deep Springs Road in Central NY (Madison Cty). DSR, as it is known, has a shale outcrop that rests at the farthest edge of the Windom Formation, but the fauna is quite different than what is found at Penn Dixie. For example, instead of bountiful Eldredgeops rana, they are much rarer here, and in their place are more Greenops sp. and Dipleura dekayi. Also, the real stunner is the enormous diversity of bivalves and brachiopods. It is also quite abundant in Devonian plant pieces, larger cephalopods, phyllocarids, and other goodies.
Our crew gearing up to work.
We arrived just after 10 am, having gone through the scenic rolling hills and farmlands of Central NY. We were greeted at the site by so many of our Fossil Forum friends, some of whom I got to meet in person for the first time. There was no shortage of fun-loving personalities here, and the amount of camaraderie, sharing, and helpfulness was exceptional.
Jay and me ready to start wrecking it all up to do some serious landscaping.
Within five minutes, I was ready to get to it. In the picture above, that wall behind me would be the first to be ripped out to generate a lot of slabs for splitting. By the end of the day, I would have cleared an area 2 m x 2m x 1.25 m.
This slab simply has to go, 150-200kg or not.
Unlocking fresh stuff requires some slabbing, something I tend to enjoy doing. After some overburden was cleared, it was time to maneuver this one off the ledge. As can be seen above,. the rock is heavier than me as I sit on the pinch-point bar which was bending. Eventually, I was able to work from the left wall, wrestling it out, and driving it with my boots down the hill for others to split.
Group shot. From left to right: Dave, Jay, me, Mike, Tim, Dave 2, Jeffrey, and Leila (who fed us scrumptious homemade cookies).
The weather had been promising to make this trip a real bust, but fortunately we only had some intermittent drizzle, with the rest of the time being clear and not too hot. Everyone came away with lots of interesting finds, and friendships were formed or strengthened in breaking rock together.
Bivalves and gastropods. I'm not really up on the taxa, but these are fairly typical finds for this site.
More neatly ridged bivalves.
Large spiriferid brachiopods are fairly abundant at DSR.
On the left is a nice association piece: a spirifer, a Greenops pygidium, and a Devonochonetes sp. . On the right is a high-spired Glyptotomaria.
A well-preserved Cimitaria recurva.
Deb found this wee Greenops that might be complete once I can remove some matrix. This one is barely a few millimetres long.
As Eldredgeops rana are not common here, I bucketed this roller.
Large cephalons from Dipleura dekayi. Finding them full as opposed to moults and disarticulated bits is an event. I think only one of us found a complete prone that day, while someone else found a complete one with the head disarticulated.
More Dipleura dekayi. I'll need to probe this piece a bit more to see if they might be complete (but I somehow doubt it).
A nautiloid and an ammonoid fragment.
With the collecting day over, it was time for us to get back to the Buffalo area. As is natural for us fossil collectors, we never miss an opportunity if we're collecting together to share some gifts. A massive amount of gift exchanges ensued! I was sure to hand out plenty of goodies from Arkona, as well as whatever Ordovician extras I had lying around. Pictured up here is a lovely Herkimer diamond from Dave. These quartz crystals are quite spectacular, and regularly have inclusions of anthraconite.
Another of Dave's wonderful gifts: an assortment of mostly brachs, bivalves, and gastropods from Cole Hill Road.
The other Dave put out a box for all of us to take whatever we fancied. This is a fern from the St Clair site, a site that is no longer open to public collecting.
Of course, little did I know that Tim remembered that Deb really liked those St Clair ferns, and so she received some pieces as well!
Tim gifted me a plethora of trilobites. Two new species on my list: Crotalochephalina gibbus (the Devonian phacopid from Morocco at the very top), Changaspis elongata (a wee corynexochid from the Cambrian, China), a full Greenops sp. from DSR in case I had no luck, and three nodular Eldredgeia venustus from Bolivia.
And the second bunch from Tim. A large Elrathia kingii with cheeks intact + impression, and the rest are Eldredgeops rana.
And Jay gave me a copy of the reprinted classic, Geology and Palaeontology of Eighteen Mile Creek by Grabau. The taxa listed in this one is pretty much the same as what is found at Penn Dixie, and some of those taxa are now outdated or reassigned. But it is indeed a classic from a real pioneer and giant of palaeontology.
DAY 3 - Penn Dixie
After two days collecting with Fossil Forum friends, it was now time for Deb and me to hit out on our own. Plans to visit another site on Sunday were nixed on account of weather... Yes, it was snowing in the Buffalo area! Deb went shopping in the morning, but by the afternoon the sun was out, so we figured we may as well play at Penn Dixie again. Although it was 10 C, the winds were bitterly cold.
Deb standing in the newly excavated zone we were all working on the Friday.
We decided to make a go of trying to find the elusive trilobite layer. This involved a great deal of hauling out slabs. Again, we treated the piles for the Experts event as off-limits.
The Smokes Creek layer is usually at or below the water table. This is what one of the gully areas looked like before I came in to rip out about 2 m wide of slabs. Sadly, the rock was far too dense, and shattered rather than split. Much of what was coming out was just bits and pieces anyway.
This trio of images shows the process required to access fresh material. As these slabs at the contact layer tend to interlock, it is important to kind the keystone slab to unlock them. In this instance, I've used the chisel to exploit and widen a crack running vertically. This one is tucked under another rock, so I had to use the pry bar to wiggle and jiggle it out. After that, I flip the rock over and scrutinize the underside; if there are trilobites or impressions thereof, I then carefully inspect the mini-domes at the site of extraction. As the water is muddy, this is largely done by touch. After that, it is time to remove another slab or split the ones I have.
Probably my best find of the day. The split runs right through the trilobite, but some crazy glue and prep will make this fairly large one turn out just fine.
This one came with a small price to pay. As I was tossing down a slab, it hit the pick end of my rock hammer, which then came at my face like a bullet. It struck and split my cheek, not far from my eye! It could have used a stitch or two, but I simply clamped it together with a bandaid.
Day 4 - Penn Dixie (Again)
After three days of slabbing, splitting, pounding with sledges, wrestling with pry bars, shovelling tons of overburden, my body just about had it! It was also our departure day, which meant we needed to get back on the road by 2 pm at the latest. So we agreed to inspect the newly excavated Bayview brachiopod area where, last October, we were pulling out buckets of brachs.
This stuff splits fairly easily - sometimes just with your hands. Trilobites like Greenops are much more common here, but the shale is so thin and fragile, and the trilobites usually only come out as disarticulated bits.
Brachiopods come out easily from the shale, if they haven't already weathered out and make for some easy picking. These are from about a minute of searching. Inasmuch as we agreed that we'd just do some light surface collecting, after 20 minutes we were getting bored with the brachs (we still have several hundred of them from October's visit),.so we went exploring back to the trilobite beds in search of a plentiful area.
Going through my splits, Deb finds this beauty.
A spot-check on some nearby rocks indicated that this particular area on the site might prove productive. Pictured here, after I removed the covering slab, is a very large dome. Domes at PD can either be full of trilobites or full of nothing.
Paydirt! We finally found the productive part of the layer. Although none of these are complete, it is strongly indicative of the presence of more assemblages in the depositional environment. Of course, it was almost time for us to leave just when we found the sweet spot. But we did manage to pull out a few rollers and near-completes that I haven't had a chance to photograph yet, but I think I've got the real highlights here in this post anyway.
And so it was back to Canada after a four day adventure. I was beyond sore, of course, but overall it was great to collect with friends old and new, enjoy the outdoors, and come away with treasures found and gifted.
Upcoming digs will likely be in the Arkona/Thedford area, and a trip to Bowmanville at the end of this month. Until then, time to manage some new backlog on the prep bench!