Despite some flirtation with the freezing mark the past few days that is looking to put my Friday trip to Arkona on hold, on the whole spring is definitely showing itself. This one is just a short post to highlight some river finds, and show off my newest Russian asaphid. UPDATE: actually, two.
On Monday I went back to the river on campus, remembering this time to bring my trusty rock hammer. There was not much to be had among the dull, plain, river-worn rock and the plentiful limestone only filled with tiny shell hash, but closer to the end of my time there before having to teach, I pulled out these odd beasts. Once I got confirmation of what they were, and that they are somewhat rare, I went back to collect the rest the next morning.
So what are they? I've seen these before and just dismissed them as some kind of wacky brachiopod. Not so! They are somewhat related to bivalves but occupy a place all their own as being rostroconches. These planktic, valved creatures would more resemble a taco than a clam. Their hinges are somewhat weak, and they have a long rostrum (the piece on the far left, centre shows it best - the striations that appear like someone scraped it). Looking at the comparable species in the general strata, it may be a Conocardium cuneus. It is a first for me ... at least the first time I've kept one. It was interesting to learn that finding these is far from common, and yet I pulled all of this from a single rock.
This is another lovely Russian asaphid, the fifth that has arrived in my collection, and with five more to come. This would be a nice, prone Asaphus plautini from the Mid-Ordovician, Aseri Stage, collected from the Gostilitsy Quarry near St Petersburg, Russia. It is about 62 mm long, so about average for this species. Here is the evolutionary sequence chart from thefossilmuseum.net:
But wait, there's more! Today I welcome species #6 to the family, Asaphus kotlukovi:
I received a piece of limestone matrix from a quarry near St Petersburg containing an asaphid trilobite. I'm giving it a go. Not complete, but pictures of the progress thus far.
The initial state of the matrix above.
This one has been a bit of a challenge. A lot of the matrix is nice and soft, but there are "sticky" bits. I knew that the piece was not going to be museum quality, so I expected there to be a bit of damage. The thoracic area at the axis was already missing some shell, so I was not surprised when uncovering the rest that it would be missing. Unfortunately, I don't have any spare pieces of this to attempt a minor restoration.
I did goof in one area, breaking off a bit of the shell. After uncovering the bulk matrix and performing some pin prep, I stabilized some areas with crazy glue, used the air abrader, and then brushed acetone on it to remove the gobs of glue. A few more pin prep attempts and I think this will have to be about it:
I have a soft spot for large asaphids (who doesn't? LOL), and the ones that occur in the Aseri Formation in St Petersburg, Russia are quite stunning for their size and apparent simplicity, if not their variation. As time went on, and with more turbid seas, these asaphids started developing longer eye stalks, or peduncles, so that they could - like modern day crabs - keep themselves buried while only their eyes would be above the sediment on the look-out for predators or prey. I recently purchased a Asaphus kowalewskii a few months ago, which also represents pretty much the extent of eye stalk development.
(Photo credit: http://www.fossilmuseum.net/Fossil_Sites/trilobites-russia/rissian-asaphida-trilobite-evolutionary-sequences.htm)
Above you can see the evolutionary progression of the Russian asaphids. Arriving in the mail today were two more to add to the family:
This enrolled specimen is Asaphus cornutus. The rolled up appearance gives it a kind of "Kermit" like look. My forum friend Roger has an Isotelus gigas (also a related Ordovician asaphid) that he nicknames Kermit.
And this lovely and large prone is Asaphus punctatus. I'm pretty happy with these two new trilobites.
Last I checked, it's still winter, and that means no possibility of getting out to collect. However, needs must when the devil drives and all that, so I have been doing some collecting indoors.
I am going to kick this post off with something very close to home (as in, at home!).
This pygidium was found among the many pieces I collected from my honey hole in town. When I first found it, I thought little of it and just threw it in the bag. However, now that the snows keep my troublemaking relegated to the indoors, I decided on a Sunday afternoon to look a bit closer at stuff I stuffed into containers from the previous year. This one is bereft of an identity at the moment. I've searched the literature, from Ludvigsen to Lesperance, to Levi-Setti to Whittington, and can't seem to get a proper ID on this lower Devonian trilobite. If anyone out there knows, I'd be grateful to hear from you in the comments.
So, setting aside mysteries, I purchased a few trilobites - one from eBay and two from a fellow forum member.
This is the eBay acquisition that I got very cheaply: a Declivolithus ?alfredi from Morocco. This is a neat looking asaphid trilobite from the Ordovician with a kind of textured "fan" that reminds me of harpetid bugs.
Adding another Moroccan trilobite to the collection (recalling I also have a Drotops megalomanicus acquired in July, 2017), this is an exquisitely well-preserved Hollardops sp. I got from a fellow forum member. The eye lenses show great detail, and I can tell it's genuine as opposed to the many fakes out there because of one very telling detail: notice the crack that travels across the specimen? The first picture shows it best. That is known as a discovery crack, and that is how these trilobites are found in Morocco. The matrix is ridiculously dense, so trilobites do not come out nice and clean. Instead, diggers will find a whisker line that shows the presence of a trilobite. From there, they glue the two pieces together and prep it out. This one looks very similar to Greenops, but this style for phacopids was quite popular in the Devonian!
From Russia with love! Yes, this is an Ordovician trilobite from Russia, Asaphus kowalewskii. It is a commonly sought after specimen due to its long eye stalks, or peduncles. Sadly, despite all noble efforts from my friend on the forum, the postal service still managed to damage this one, so it took an hour of trying to reattach several pieces of the peduncles. They may not be in their proper orientation, but you haven't explored your full lexicon of expletives until you try to use crazy glue and tweezers to try and restore broken peduncles. Despite its current state, it still finds a home here.
These trilobites, for some reason, developed long eye stalks. It has been reasoned that it was to be able to see in highly turbid waters, or to be able to continue their benthic existence safely while being buried up to their eyes. What is particularly unique about them is that they are only found in Russia.
And that isn't all. Yes, wait, there's more! - But that will have to wait until packages arrive. I have traded some spare trilobites with forum members in the Netherlands and South Korea who have some lovely bugs to send me in return. I also have another exotic Moroccan bug coming from England. I'll update this post or make a new one when they all come in.
Apart from that, I did some online shopping for fossil necessities. Coming in the mail will be a pin vice, which will spare my poor hands and fingers in using sewing needles for fine prep. I'm also awaiting a tactical backpack to replace my rather worn backpack that is pretty much unusable now as a cat peed on it.
But, so far, 2018 has seen the arrival of three new species to my collection, and one mystery unknown! I anticipate from between 4-8 new specimens in the next few months. Starting off the collecting year - in pre-season - strongly!