One of my fossil forum chums, Ron from Montana, shipped to me a big bug in a box. This thing makes all my other trilobites look puny!
He also threw in a sweet little ammonite with some opalescent lustre:
And here are some pictures of the big trilobite. It is from Morocco, and it looks like a Drotops megalomanicus. As there is a thriving cottage industry in Morocco in producing fakes, I've inspected this carefully. No resin bubbles, and these trilobites have some black calcite. It doesn't look like an restoration work was done on this one, and some of the prep was a bit rough. It is mostly covered with pustular little nodules, some of which seem to have been abraded off by a bit of sloppy preparation. Still, a very large trilobite at about 5 1/2 inches (12.5 cm).
Nothing too remarkable about the finds from two trips to Hungry Hollow, the first with Roger, and the second with my Deb. But I may as well post some finds.
On the Tuesday trip with Roger, we did scour the north pit, hacked out some slabs from the north river exposure, and ended by doing some surface collecting in the south pit. On the Sunday trip with Deb, we focused on the south pit since the north is filled with deer flies in the dense bush.
I looked in vain for the other half. This was worked out of the coral layer of the Hungry Hollow member.
Deb splits a coral to get a look at the structure inside.
A typical hash plate from the Hungry Hollow member, the layers without as many corals. You can see some trilobite cephalons in there.
Brach-encrusted shell pavement from the Arkona Formation. Found with Roger on the north pit part of the trip.
Not entirely sure what this is yet (to be updated). Could it be a Basidechenella trilobite glabella? About an inch long.
A pelecypod from the coral layer.
Lots of stuff going on here. Trilo-bits, a possible fish plate, tons of crinoid bits, a Platyceras conicum (lower left), brachs, etc.
Next up are a few of Roger's pictures and finds after he cleaned them up:
Roger snaps a picture of me up in the bench.
We were finding a few of these pyritized orthocones in the Widder shale. Not in itself a rare thing, but this one is intriguing.
These Tornoceras arkonense really clean up well! You can pick them out of the Arkona shale, but they also come out a bit bigger in the Widder shale. One must just be on the lookout for a bit of metallic glint, suggestive of something pyritized - and it could be one of these.
This one is a bit of a mystery. It is about 7 mm, but has some strange suture patterns. We're not sure which of us found this in the Arkona Fm, but that is immaterial. It is not a Tornoceras, and neither of us can find this ammonoid described in the usual places (such as the Stumm and Wright checklist or on the UMMP database). Could this be a new and undescribed species?
I had a fantastic time yesterday collecting with Roger, who makes an annual visit to Canada from Germany to see his family. We spent the day at Arkona where I showed him my productive spots on the north side. Many neat things were found.
Rather than post the finds in this post, I wanted to dedicate this one to Roger's generousity in gifting me some fabulous ammonites he has collected from Germany, very nicely prepared and coated in beeswax. Enjoy!
The last two on the bottom row are interesting and fully inflated brachiopods.
Apart from the very nice colour and thick-ribbing, I had to show the fascinating and well-detailed keel side.
I just wanted to provide another update on Malcolm's continued and excellent progress on some of the stuff I handed over to his care. You might recall that I found a Ceraurus during my first trip to Brechin. It was pretty submerged in the matrix, but I've read that this is ideal since it hasn't had much exposure to weathering.
So the picture on the left is how I found it. Obviously, it is missing a bit of its tail piece here and is pretty encrusted in matrix.
A few days ago, Malcolm posted some pictures of what he was able to salvage from this one.
Take a look at the results below. Absolutely fantastic. This bug's a bit beat up and missing the tail, but in all a good and nearly complete specimen made all the better by Malcolm's preparation.
Anyhow, a brief post. I'll likely be posting another next week when I hunt Arkona with Roger.
UPDATE (Aug 30, 2017): This specimen is now featured on Mineralienatlas Lexicon)
As a supplement to my recent trip to Brechin, Ontario, Malcolm Thornley offered to prep out a complete Greenops widderensis I found last year. The frustrating thing about these trilobites in Arkona is that they tend to be very fragile and flaky, and most times you find just tail pieces or parts of the cephalon. They only very rarely come out nice and whole like this one. You can go through tons of rock for just one half-decent specimen.
Before this received its masterful prep, I gave it a go using my primitive tools - a Dremel engraver and a sewing needle under a magnifying lens. Here is what I ended up with - as far as I would dare with such a specimen:
Ok, so not bad - but far from museum quality. For that, you need the right tools and the expert touch only a seasoned prep-artist can provide.
Malcolm spent a good amount of time with this one, using a Comco abrasion unit at 7 PSI, with dolomite as the abrasion substance through a 320 mesh screen. He worked out all the scuff marks of my Dremel and removed some of the excess matrix. Using a .015 nozzle, Malcolm prepped this using his Nikon scope at a magnification of 14x. Here are some images he provided of the process:
And finally, below, is the finished masterpiece. He used a .010 nozzle, as small as they may come, to get out the grit between all the nooks and crannies. As Malcolm told me, there were no restorations or use of consolidants. The only imperfection is a bit of damage to the pleura on the mid-right side, but beyond that an exquisitely preserved - and now masterfully prepared museum quality trilobite! I am certainly in awe of his skill.
And, just to compare, the top image beside where this bug was before prep, and halfway through the process, just to show the big difference a good prep can make
Deb and I made the four hour drive up to the east side of Lake Simcoe to dig at a quarry in Brechin. This was my first time working an active quarry, and it was exciting (and potentially fairly dangerous if you don't properly observe some common sense and safety precautions). It was about a day and a half of rummaging through the rocks on mostly sunny and hot days. But we didn't come away empty-handed!
Deb and me ready on our first day. We arrived shortly after 2 pm. Francie from the Ohio Dry Dredgers and a few of their members were just finishing up. They had just come up from Penn Dixie, and we thank Francie for snapping our picture.
I cannot stress enough that this is an active quarry with regular blasting and areas that are not entirely safe, so there is no messing around here. Full safety equipment (steel-toed boots, hard-hats, and reflective vests are absolutely mandatory), and it requires signing a legal waiver before entering the site. On the right is the entrance.
On the left is just some of the mountainous crush piles. To the right, I'm hauling our wagon full of gear to the uppermost tier flanked by some gullies.
This is a view from the second level overlooking a part of the pit. For a sense of scale, a person standing at that back wall would look little bigger than a dot in this picture. The machines below are quite large. The stratigraphy is mostly Verulam Formation from the Ordovician, with some Bobcaygeon Formation now being dredged out from the base.
Again, a bit tough to make out scale, but the drop here is precipitous. That rock near the top could fall at any time, so it is generally a good idea not to be poking around directly at the base of any of the walls. The usual rule is to keep about no closer than a 45 degree angle from the top of the wall. A lot of loose stuff out there just waiting for any tremor to send it all down - and no hard hat is strong enough to save you from a few hundreds tons of limestone crashing down!
A typical hash plate rich in crinoid and other bits. I tend to either photograph or take home interesting hash plates, and particularly from places I don't get to collect from very often. It gives a sense of the marine bed.
Another hash plate. The Verulam limestone itself is mostly storm-tossed debris as opposed to just the quiet deposition of organisms and sediment over time. In some rocks, you can see the violent wave/ripple of mud having had churned everything.
Two more hash plate with some rich biota. If you look very carefully toward the upper right of the second one, you can pick out the tail piece of a tiny trilobite.
One of the hash plates I brought home of a storm depost of brachiopods and some trilo-bits.
Last hash plate pics, I promise! These are just a few I brought home. The one on the left that is brown fell from the uppermost part of the Verulam and has a good collection of gastropods and a few brachs.
A few members of our crew. From left to right: Roger, Malcolm (with the rock saw), and me. Deb took some video footage of Malcolm in action cutting out a nice multi-plate crinoid slab. Malcolm has been a regular at this quarry for several years, and there is very little he hasn't yet found in terms of the large faunal variety present here.
Malcolm's infamous no-fooling-around rock saw beside a multi-plate of crinoids (picture by Malcolm)
I've been tasked with turning the rock over so that Malcolm can continue his cut to free the crinoids (picture by Malcolm).
Some high-spired gastropods (Fusispira sp) and flatter ones. These weather right out of the rocks. New material depends on the quarry to be blasting out new stuff. Deb and I found that splitting the blocks was not getting us very far - most of the stuff to be found is either weathered out, or appears solely on the exposed parts of the rock. The rock itself alternates between thinly bedded mudstone/shale and very dense encrinal layers. Splitting the mudstone usually had traces or were just blank for us.
Malcolm found this cystoid (Pleurocystites?), and was kind enough to give it to us. I'll try to confirm the species when I update this post.
Crinoid stalk. Certainly not the longest you can find here!
Closeup of a branching bryozoan (Stictopicorella?).
Malcolm tells me that this is a bit of rare one at the site. I found this in the fallen materials on the second level. It is now been confirmed by veteran fossil collectors Kevin K. and Joe K. as the bryozoan, Constellaria - and this may be only third one ever found at this site.
Closeup of a trilobite I pulled from the bottom level. I was really coming for trilobites on this trip, and I was not disappointed. The first one I found in the upper level gullies was a Flexicalymene senaria roller, but this one is a prone and partially/maybe disarticulated one?
One of the most common trilobites in this formation is Isotelus, but full specimens are a bit tricky to find. Just about every rock has bits of them. On the left is a collection of tail pieces, with the one on the extreme left a fairly large (4 inches wide) example that Deb found. On the right are some other pieces, mostly of a genal spine, a hypostome (the mouthpiece, which looks a little like a wrench head) and some head pieces (cranidia).
This I found on the second level: a ventral view (underneath side) of an Isotelus - or what remains of it. You can see the hypostome.
This is a virtually complete Ceraurus missing only its pygidial spikes. It is currently with Malcolm who will be prepping it for me.
Trilobite rollers! I had very much wanted to find a complete Isotelus, and I was not disappointed. The "Kermit" looking one on the left is virtually complete and found lodged in the strata on the second level of the quarry. The one of the far right is a Flexicalymene that I had found minutes upon exploring the site, and the middle one is a Ceraurus sp.
A closeup of the middle one.
I still have a bucket of stuff to go through, and some IDs to put on the finds. In all, it was a fantastic and exciting trip. My thanks to Malcolm for being our gracious and knowledgeable host.
The site boasts a heck of a lot of variety for trilobites alone. Below is a table of identified and described species found in the Verulam Formation by B.A. Liberty (1969) Paleozoic Geology of the Lake Simcoe Area, Ontario. Geological Survey of Canada, Memoirs 355. Since then, Ludvigsen (1979) describes a few others, including Amphilichas (a pygidium of which Malcolm found just this weekend, and is considered a rarity - and never found whole).
Update: I just performed a bit of light cleaning of the rollers and snapped slightly better pictures of them here:
I spent the entire morning on Saturday at the hill & pit just beyond my backyard. My expectations were fairly low given how much I had picked the place clean over the years, so it was my goal instead to take pictures and record some of the fossil fauna there for posterity. How plans can get upended - sometimes in unforeseen yet lovely ways.
This picture is not exciting, nor was it meant to be! I began on the southwest portion of the hill (which is now pretty weedy with burdocks and spiky plants, by the way!). I had not spent a lot of time in that lower quadrant as I always seemed pulled to the upper southwest and southeast areas. Pictured here is a typical brachiopod assemblage - some spirifers, an atrypa-type, a Leptaena, and other assorted kinds. As I said, the purpose was to photo-document the typical stuff of the Bois Blanc Formation.
Another very typical assemblage from another distinct layer of the Bois Blanc. This tiny brachiopods can be quite numerous (I forget their name at the moment). So numerous, in fact, that some of the rocks bearing them actually are more shells than matrix, and just crumble. There are several examples of this type of assemblage in the area where the brachiopods are stained a kind of vermillion.
A similar assemblage to the first picture - some atrypas, a leptaena, and a large ?Strophodonta. Bored yet?
Performed a brief scan of the upper south quadrants and assembled a few of the specimens I had set aside from previous visits. If you zoom in for detail, you'll see, left to right, a rather chunky brach assemblage (name escapes me at the moment!), a lingulid pelecypod, a horn coral, and a typical (for particular layers in the Bois Blanc as a signature feature) cherty rock with a few corals showing cross-section. By this time, I had enough of the hill and was ready to give the adjoining pit another try.
Oh, but wait - I was distracted by a rock I had split and left behind some weeks ago. I decided to break it down to pluck two bryozoan specimens. The first pictured above is a typical fenestellate bryozoan. The next is a bit more peculiar...
Now what the heck is this? I made inquiries on The Fossil Forum, but at best we might describe it as Sulcoretepora. As described by a single specimen in the Amherstburg Formation by J.A. Fagerstrom:
"This specimen is a short bifoliate stem with three rows of apertures on each flattened side and none on the edges. Slightly raised longitudinal ridges separate adjacent rows of apertures. Apparently no mesopores are present between apertures but they may have been destroyed by recrystallization" (17).
Fagerstrom, J.A. (1961). The fauna of the Middle Devonian Formosa Reef Limestone of southwestern Ontario. Journal of Paleontology 35(1):1-48.
There are some interesting branching, radiating patterns in this one, with two zooecial apertures near the upper left and upper right corner (the dimply stuff). Colony form here is likely remnant of bryozoan encrusting substrate (with thanks for our experts on the forum). But why are we even talking about Amherstburg Formation? Let's keep this flagged for the time being.
I was not expecting to find any trilo-butts, but I managed to find about six. So now I am in the pit and can confirm that it contains Bois Blanc formation rocks. I dug this rock out of the wall of the pit, and pictured above is the pygidium of the dalmanitid trilobite Anchiopsis anchiops (which only appears in the Bois Blanc), but missing its full trademark pygidial spike.
Some in situ photos from the pit as I work the same rock. The top picture shows some typical assemblages, while the two lower pictures are closeups of the most frequent brachiopods.
Trilobite impressions (Anchiopsis anchiops). I took the positives home.
After I patrolled the rest of the pit and did not find much more to my liking, it was time to go home and take stock of the finds. Pictured above is a gastropod steinkern (the inner whorl occurs on the reverse side). Beneath that is a nicely inflated clam, and on the right is another spike-deprived Anchiopsis anchiops.
This specimen, found on the hill, is the real "meat" of this post. This is not a trilobite that appears in the Bois Blanc, but solely in the Amherstburg formation. The Amherstberg is a younger formation, contiguous with the Bois Blanc if there is no Sylvania formation intervening. Note the nodules on the fringe of the pygidium.
Consulting Ludvigsen's 1979 text, Fossils of Ontario. Part 1: The Trilobites, there is a specimen reported that looks nearly identical to this one, but it is simply called Dechenella halli. The name was updated by Ludvigsen in 1986 and recognized as a new genus: Mannopyge halli.
Here is a plate from the Ludvigsen 1986 text on the left, compared to my find on the right:
Quite exciting, as this makes the 19th species of trilobite in my expanding collection (I've more than doubled it since March of this year alone). Let's learn more about it:
"A warburgelline with pear-shaped glabella, deep sigmoid 1s furrow, narrow (tr.) and faint 2s and 3s furrows; no preglabellar field, tropidium, or tropidial ridges. Large eyes located anterior of cephalic midlength; genal spines short. Semicircular pygidium iacks a flat border,-axis with 9 - 10 node-bearing rings, eight faint pleural furrows and incised interpleural furrows, each pygidial rib terminates abaxially as a rounded node isolated by moderately deep paradoublural furrow. [...] No other warburgelline has a semicircular pygidium, and none possesses a conspicuous row of fringing nodes such as that of Mannopyge. The pygidial pleural ribs of M. halli, however, are of the flat-topped warburgelline-type (Owens 1973, Fig. 2), and there is no reason to doubt that Mannopyge is a late member of the subfamily Warburgellinae." (Ludvigsen 1986, 683).
Ludvigsen, Rolf (1986). Reef trilobites from the Formosa Limestone (Lower Devonian) of southern Ontario. Canadian Journal of Earth Sciences (24): 676-88.
Two remarks: First, this tells me that there are some Amherstberg formation rocks in the mix at this site. Second, trilobites in the Formosa reef limestone are not particularly common, dominated as it is by coral and stromatoporoids. Of the uncommonly found trilobites in that limestone, it is mostly dominated by Crassiproetus, followed by frequency occurrence Mannopyge halli, followed - in descending order of frequency - by Mystrocephla, Acanthopyge, and Harpidella.
I'll leave off today with a few more pictures, mostly to underscore that my picture-taking ability has seen a little boost in quality on account of having acquired the third-party app, Camera+, so that I can take proper macros. Using an iPad to take closeup images can be a bit unsatisfactory, but the app I purchased allows me to get in much closer and increase the resolution (which is probably why those of you with slower bandwidth are cursing me right now). As a test, pictured above are two sides of the same piece of crinoidal limestone found at Penn Dixie.
And this is a closeup of a coral piece from Arkona. I'm pleased with the detail.
Ok, enough from me until next weekend, when I'll be headed to a quarry east of Lake Simcoe for some serious Ordovician collecting. Until then, thanks for reading!