When it rains, it pours. With what were to be the last big two trips of the season -- one to my prospected Cobourg Fm roadcut near Nottawasaga Bay, and the other to Bowmanville -- were bust. The trip up near Collingwood did not yield any complete trilobites. Worse, the stuff was weathering into blank, undulating nodules with the occasional bits. Small, junky fragments of about five typical Cobourg Fm trilobites were all I came away with, and the usual giveaway gastropod steinkern and miscellanea. I spent a good deal of time (including in a misting rain on a cool morning) splitting to no avail, and surface collecting the weathered rubble to slightly better luck. Photos of my underwhelming finds: So, Isotelus, Flexicalymene, Ceraurus, Pseudogygites... in fragmentary form + gastro and sundry bits. The "prize" were all these Thaleops cephalons. So, fairly skunked for an eight hour round trip drive. I won't be bothering this roadcut anymore. As for Bowmanville, funny story. Forty clicks out from London as we are making our way, our car decides to give up the ghost on the 401. That means getting a tow back into town, it means not being able to get refunded for a hotel room some three hours away, and it definitely means no coveted Bowmanville trip for me. As trips to the quarry are limited to the two times a year they let collectors in, and with a new rule about putting a hard cap on the number of collectors, my luck in not being bumped to the waiting list for next spring meant little if our wheels would not get us there. So, what was going to be the final big trip of the season went up like a puff of smoke. That bummed me out a bit. But the season is not quite done as I continue wrestling the stone at my personal backyard spot. It's a lot of fighting to get the rocks out and broken down, with some just too large to do much other than shatter. But here's another pygidium of Acanthopyge contusa. Genal spines belonging to another lichid, but unsure if it belongs to Acanthopyge or Terataspis. None of my literature describes the genal spines of Acanthopyge contusa, so it remains uncertain. A giant and fully inflated Crassiproetus pygidum. Two poorly preserved lichid pygidia, and an uncertain fragment. Another Acanthopyge contusa cephalon (two angles). The mystery deepens, or am I closing in on the formation these rocks are coming from? I still need to retrieve the positive, but my trilobite comrade Scott says it seems to compare to Trypaulites erinus. Initially, I had passed it off as a Pseudodechenella until I got home and looked at more closely: too many pygidial ribs and an axis much more tightly tapered. A dalmanitid! This one sits on the exact same bedding plane as the Acanthopyge pictured above, with only about 3 cm of daylight between them. So... what are these rocks? According to the reported material, the Bois Blanc Fm has the following trilobites:
Terataspis grandis Anchiopsis anchiops Burtonops cristata Crassiproetus crassimarginatus Pseudodechenella planimarginata Otarion sp. Calymene platys Trypaulites erinus The ones in bold are those that I have found in this imported fill. But the trilobite out of place here is the Acanthopyge contusa that is only reported in the overlying Amherstburg Fm. The evidence seems more to suggest that a) I am dealing with Bois Blanc material for sure, and b) Acanthopyge specimens in the mix may mean it had a longer geological range, first appearing a bit sooner. That would not be an entirely absurd hypothesis. ___ The rocks at my spot are starting to thin out in terms of giving up nice finds, taking much more effort for less reward. As the days grow shorter and colder, the fossil days of the season are in their twilight. That being said, it is not officially "down tools" yet; there are still a number of weeks left where I can squeeze out the odd day or two a week between teaching duties. In the hopper is some planning to visit the type locality of the Formosa Reef (Amherstburg Fm). Full trilobites in those reefal environments are as unlikely as my current backyard spot, but I'm hoping to find a fragmentary example of at least one species of trilobite I do not have as this year has been a bit light on collecting species I don't already own. I'm also expecting a scribe I picked up for cheap that will bridge the gap between my ME9100 and the Aro, and I have another Asaphus lepidurus coming to be prepared. Looking over my materials this year, I'm not sure I'll have enough to last me through the winter, so I may spend more time planning out the 2020 season. But it's still the 2019 season. I will continue breaking rocks until the snow comes. Comments are closed.
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Kane Faucher
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February 2024
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