A fossil friend of mine on the Fossil Forum, Jason Rice, recently sent me a package of goodies in trade for some spare material I had on hand from Arkona. The top row has some mouth plates and shells, while the bottom four rows are all fossil shark teeth. These are quite special for me as they represent the first shark teeth in my expanding collection. These are from the Miocene period, 6-20 million years ago. The teeth are definitely worthy of a close up image. This large fossil scallop is Chesapectens nefrens - a fairly popularly sought out one. The trilobite Elrathia kingii from the Wheeler Formation in Utah. Middle Cambrian (~550 million years ago). Another Asaphiscus wheeleri, with impression. It is fairly common that one finds these without their cheeks as they moulted their old carapaces and exited through their cephalons. The most iconic of the Utah trilobites, and the one you see most commonly sold in rock shops, here we have Elrathia kingii with a tiny friend - a "mini-me" version, if you will.
All very exciting stuff! Not only does this boost my trilobite species count for the year, but particularly Cambrian trilobites (see my post on the ones I acquired from Marcus here). As there are no Cambrian exposures anywhere near me, these are a real treat. Day 1 of 3: Craigleith AreaDeb was on vacation time, and so apart from a few beach days and staycation relaxation, we spent three days on the road. Our first stop was Craigleith near Collingwood, and we took the stunningly scenic route through Grey Highlands. The Craigleith area is filled with Whitby Formation shale overlying the Lindsay Formation limestone. You cannot legally collect from the provincial park, but there are a few very tiny spots left outside of the park where one can split a few shales to find a lot of Pseudogygites moults. At the park itself, there is a display area of fossils. Pictured above is a fairly large orthocone nautiloid - they got pretty big in the Ordovician. A complete Pseudogygites latimarginatus. Full ones are exceptionally hard to find as it is more common to encounter enormous hash plates filled with moults. A conularid. A fairly representative hash plate of Pseudogygites latimarginatus trilobites and brachiopods. Pieces from over a dozen in this shot alone. Another representative species of trilobite in the Whitby Formation is Triarthrus. I might be able to free up some of the overlying matrix on this one. It is partially pyritized, although it is tough to make out in this photo. The pleura of an Isotelus sp. in the Lindsay Formation. These small, feathery creatures are also common in this shale. These are graptolites. This is indeed a complete Pseudogygites latimarginatus. A bit crushed and torn, but all the pieces seem to be there. Nice! Day 2 of 3: Oro-Medonte to Gamebridge and beavertonAfter staying in Oro-Medonte / horseshoe valley, we made our way to our B&B in preparation for the big quarry dig on the following day. Although not a fossil collecting day as much as simply a touring of small town Ontario, there were a few rocks around. Deb took lots of pictures of some living creatures like sand pipers, geese, monarch butterflies (so many!), and a cormorant. In Beaverton, we took a stroll along the pier where the sides were shored up by Verulam Formation riprap. The Beaverton riprap: weathered gastropod hash. Crinoid hash plate as part of the landscaping toward the old mill park in Beaverton. We took a walk to Gamebridge's locks system, and then upriver where there were pockets of Verulam limestone. Pictured here as an appetizer to the main event for the next day in the quarry is a brachiopod hash with a piece of Prasopora on the right. By the same river, a crinoid stalk terminating with half a calyx showing, plus the impression of arms flowing from it. A neat piece! Last river piece: a hash of mostly brachiopods and bryozoans Day 3 of 3 (The Main Event)I was so excited to get into the quarry that I was up at 4 am and left the B&B at around 5:15 during nautical twilight to make the five minute walk to the quarry. I deposited the legal waiver forms, suited up with the hardhat and reflective vests, and poked around to look at the rocks the best I could until the sky lightened up a bit more. Those who have read my previous post on Brechin's JD Quarry (here) already know the place is incredibly vast and overwhelming. Top left: a large cephalon and genal spine of an Isotelus (fragments abound here, while full ones are very hard to come by). Top right: more Isotelus bits with a Flexicalymene senaria cranidium in the centre. Bottom: typical busy hash plate of assorted crinoids, trilo-pieces, bryozoans, and brachs. First blood is a prize find: a semi-prone Flexicalymene senaria in the scree at the top level of the quarry. I found it in two pieces and had to stabilize it with crazy glue. Unfortunately, the pin that functioned as the stopper for the nozzle had snapped off, so my glue bottle would be one use only. This piece is still, however, lovely and quite robust. Eventually, I was joined by Malcolm, Kevin B., and Jabali. We split some new blast piles, and also worked on the new area hauling out tons of rock where Malcolm had found some exceptionally rare cystoids. Sadly, it looked like what he had found the weekend before was an isolated death pool, but it felt good to move enormous slabs of Bobcaygeon Formation limestone. Just to give you a sense of how serious we can be, one piece we moved had to weigh over 700 lbs, and I ended up snapping a steel pry bar. Groar! I spent the rest of the day trying to cover ground, going through weathered piles of scree along the upper ledges and wandering the immensely mountainous crush piles. We don't screw around. Jabali snapped Malcolm and me trying to pry this big rock into the pond. We needed to remove from the top down by a good six feet to see if the cystoid layer was going to continue. Bottom of the quarry, new blast pile. Crinoid stalks can run forever here. Close up of crinoid stalks. In situ photograph of a full prone trilobite, Flexicalymene sp. Sadly, as I didn't have any glue left, I wasn't able to stabilize it. The tail piece of this one is now missing. What survived transport. I might be able to very delicately tease out the left side. The pustular glabella is poking out at a vertical angle on this piece. Not sure yet what species this is, but will update when I find out. Update: it is looking like I have myself a Calyptaulax callicephalus. Trilo-pieces. Top right: impression of a pygidium with a margin (to be identified). Centre: Possible Flexicalymene cranidium (to be confirmed - actually no: see picture below). Bottom left: pygidium and some pleurae of an Isotelus. Well, what do you know? I get to add another species to my collection. Thanks to Don C. from the Forum in planting the bug in my ear that this might be an Achatella achates, an uncommon phacopid trilobite. I just picked off some of the matrix here to reveal the telltale diagnostic features of this species. Both plates contain partial Ceraurus. Assortment of trilobite pieces: Flexicalymene, Isotelus. The big Flexicalymene found at the beginning of the dig is joined by a Flexi roller I found in the afternoon. This one in need of identification. I have some ideas, but it's just guesswork at the moment. Some big honkin' pieces of orthocone nautiloid. The one on the lower right I make have to photograph independently as it is the very end of the taper, and with a brachiopod association. The middle one may be Geisonoceras. A hash plate with a gastropod on the left, and some trilobite pieces throughout. A close up of this hash. The cranidium belongs to Calyptaulax callicephalus. Deb found this tiny pygidium. Species needs identification! I love these high-spired gastropods! The majority of these are Fusispira sp., (and others like Hormotoma and possibly the thin one being Subulites) and the cluster on the lower right with the pinched spires is likely Lophospira sp. I can't help but to pick up crinoid pieces. Low-spired gastropods that weather out of the matrix. The one exception is the corkscrew-shaped high-spired gastropod I missed when I took the initial "family photo" of high-spired gastros earlier. A collection of brachiopods. The bottom two levels are a very typical heart-shaped species - various types of Rhynchotrema. Odds and sods: top two rows are sponges and bryozoans. Bottom two rows are trilo-pieces. Bonus Round!Before Malcolm left for the day, he gifted Deb and me some fossils. The trilobites I had found and given to him for prep, and I now get to see them in all their expertly prepared glory - my thanks, Malcolm! This is one of the many pieces Malcolm gave us: segments from a eurypterid (a sea scorpion from the Silurian). The are likely from the quarry in Fort Erie, and so are very hard to come by these days. Readers of the blog will already be familiar with this Greenops widderensis. Some Eldredgeops rana I found at Penn Dixie, after Malcolm's masterly touch. The next three images are closeups to show the exquisite detail. Simply wow.
Stay tuned: on Monday I am receiving a gift of fossils from fellow fossil collector Jason Rice, from Utah! With the appearance of yellow in the trees, reminders from the dean to submit the syllabi for the Fall semester, it all points to the end of summer. It also means getting in as much rock-breaking time before school duties resume. A trip to Arkona - my nth one this year - did not yield up many wow specimens. My goal of finding a full Greenops widderensis has not borne much fruit this year for some odd reason. But I did come close on a few occasions. This time, I crossed the river to the south bank for the first time (not to be confused with the south pit). While on the south side of the river, there were some mighty large corals. I left them there since I already have enough coral, and I didn't fancy hauling all that around with me for the rest of the day! This one is a real heartbreaker. Two nearly complete Greenops (one of which is just an impression), with a third one showing. As readers of my blog already know, the trilobites in the Widder Formation are quite delicate and flaky. Not only does the Widder shale not commonly follow regular bedding planes, breaking anyway they like, but any exposure to rain will cause them to fracture and crumble into little chips. Finding these bad boys intact, and not just endless moults, is rare. After about two hours on the south bank, there really wasn't much to find. The cliffs were too vertical to risk chopping out benches, and all the fallen slabs had been split and picked over. And so I defaulted to my usual location on the north side of the river, attempting to continue some benches and find some trilobites. While splitting for a few hours, this oddball showed itself. No, not a fossil snowflake, but a hederellid - a kind of branching colonial animal that usually affixes itself to brachiopods and corals (thanks to Don C. on The Fossil Forum for the ID). Some of the orthocone nautiloids that come out of the Widder can be very impressive as they are usually pyritized. However, they are also very delicate in that unforgiving shale. The pieces below all belong together, but it will be a matter of Humpty Dumpty to put them into their proper shape as some of the pieces crumbled into nothingness when I attempted to clean them. Derp. The grey shale pieces here all come from a very thin layer I was working where it seemed the Greenops were coming out relatively whole. Following it horizontally, and spot-checking vertically at various parts of the strata, ended up in the trail going cold - just butts, bits, and pieces. Notice the squished one at the top middle... ...So I gave it a quick and careful application of the engraver to pop off some of the matrix. I might risk doing a bit more to see if the cephalon is still there. One has to be very careful in using vibration tools as the trilobite itself is liable to flake off. I might apply some quick crazy glue before trying again. It was getting close to departure time, so I made my way out of the river and woods back to the north pit, and then scanned the Hungry Hollow Member for little bits. This fairly decently sized Platyceras was only showing a tiny bit of spine from the dirt. Digging it out, here it is in its large glory. Spines on this coprophagous species usually only appear on the juveniles, which can be very tiny (0.5 cm or less!), so it was surprising to see them on such a large one. Here are two other pictures of the same specimen from different angles: That's about it for this time. Next weekend I hope to be making a trip back in time to the Ordovician - stay tuned!
So today I decided to spend part of the morning at that site near my house, the infamous "riprap hill" and associated pit. I've long suspected most of the rocks I split there were trucked in, and have confirmation of that due to the three different kinds of trilobite I've pulled from it (two in the last four months - Anchiopsis anchiops and Mannopgye halli). I had been finding examples of rock from the Hamilton Group, Dundee Formation, Bois Blanc Formation, and the Amherstberg Formation. A good and wide range of Devonian age rocks. As can be seen above, the usual assortment of brachiopods and a gastropod. My expectations were low as I'm running out of rocks to break after four years of scouring the place. Ok, but what about this? I get the line by Morpheus in the Matrix in my head saying "what if I told you everything you knew was a lie?" So at first I was in disbelief: this must be a shell impression, not the impression of a trilobite pleura. But I've seen this before. In the Ordovician. Yes, it is a fragment of a Pseudogygites. The nearest Ordovican outcrop is 300 km away. If I needed further proof, I flipped over this piece of shale and saw a fossil barely bigger than the head of a pin. Putting it under the microscope, it is indeed the cranidium of a Triarthrus. Oookay, then. Confirmed: dumped rocks that span over 100 million years. From a field perspective, this is going to make things much tougher in terms of certainty over finds, but I suppose it means a veritable potential bonanza of finds spanning a much broader range of geologic history.
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Kane Faucher
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February 2024
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