In an effort to turn the collecting season around (which, on balance, hasn't been bad), I managed to get out to Arkona three times in the last seven days, each one with a different field companion (Deb, Malcolm, Greg). We worked the Hungry Hollow Member almost exclusively. Those who have made that 2-4 feet of strata understand how frustrating it can be to work in: generally crumbly, dirty, virtually no bedding planes, and so filled with coral that if you never see horn coral again that would be too soon! This is generally the kind of stuff one has to go through. It is quite dominated by coral, but there are shaly pockets where crinoids, bryozoans, brachiopods, gastropods, blastoids, and trilobites can be found. However, it is also a bit of a shredder: only the hardiest specimens remained intact in this high energy environment, so bits and pieces are the norm... when you can see them, as this stuff is pretty dirty. I did stray briefly to the hard encrinal layer that the Hungry Hollow sits on. Again, no bedding planes, but also brutally hard. Most of what can be found will be shattered through, or a steinkern. Perseverance can be rewarding in finding huge brachiopods, and nicely inflated trilobites (I've only ever seen partials in this layer). Pictured above is just an example I left in the field of a very large Eldredgeops rana glabella. Apologies for the rubbish photo as this hardly does justice to these (particularly the one on the upper right). On one of the days, it was Crassiproetus canadensis city. It seemed I pulled a pygidium every few minutes. Most are in pretty poor shape, which is the norm for Hungry hollow. Again, the complete specimen eluded us, but this was by far the most examples of this species I've ever collected in one trip. I should state that all of these are pretty much field fresh, and I won't be prepping them for a while as I need to build up my stores for the long winter. But if one looks closely at this plate, there are three Crassiproetus pygidia (two on the upper right, one on the lower left) plus another fragment. A bit challenging to make out, but near the bottom is another Crassiproetus pygidium that I kept on account of its massive size. Sadly, it's halfway to steinkern. A first for me in the Hungry Hollow: carbonized wood bits. Having found these as well placoderm bits this year mark two firsts as these are more likely to be found upstairs in the Widder. In the middle is more Spinplatyceras gastropods, and a few more Crassiproetus pygidia at the bottom. This was from the hard encrinal layer -- a giant Spinplatyceras. Much of the shell is gone, sadly. When tabulate/colonial coral appears in the Hungry Hollow, they can get up to the size of wagon wheels. I did extract this one as a matter of circumstance, and it is much larger than how it appears here. The other coral piece in the foreground belongs to it. As I already have an example of this monster coral, I left it in the field rather than lug it back. Other stuff from my Arkona trip bucket. The middle trilobite at the top (Eldredgeops rana) is indeed complete as I can see on the other side of its crushed/folded nature. On its left is a headless rana, and on the right a pygidium of Pseudochenella. On the right of that is a big brach and a coral. Everything else is Spinplatyceras with the heartbreaking exception of the lowest right -- likely a Pseudodechenella with poor preservation and more steinkern than fossil. This was the tripmaker: the cephalon of an Eldredgeops iowensis southworthi. Of the five reported trilobite species in the Hungry Hollow, this one is the rarest. It is rumoured that less than 100 of them (almost all fragments) have ever been found, and that the holotype is a single cephalon. I do know someone who did find a complete enrolled one. Complete, this one would have measured possibly more than 10 cm long. It can be distinguished from the ordinary Eldredgeops rana by the number of dorso-ventral eye lenses, but more obviously by its excessively tuberculate shell. In other words, far "bumpier" than a rana. This would make the second example of this species I've found in the last five years, with a third one purchased from a fellow collector.
I've put it through about ten minutes of abrasion, and it still needs far more prep. I almost didn't see it, as its initial state was like much of the Hungry Hollow: dirty and uniform in appearance. All I saw was a bit of a bump, which more often than not means yet another coral. But I spied some little dots poking through, which is suggestive of tubercles. I'm glad I took the chance to bring it home! There may be so little left of summer before work pulls me away, but I do have some trip plans I'm waiting to finalize. This may not be the last post before autumn! Comments are closed.
|
Kane Faucher
Archives
February 2024
|