Phyllocarid streak at DSR!

[Al Tahan]

Hey everyone!

 

Back at it again. This time I’ll keep it a little shorter and get to the fossils. I made it back out into the field last weekend and visited DSR and Cole Hill on Sunday 3/29/20 with fellow forum goer @DrDave. Usually we shake hands on our hellos and goodbyes like any two people would. It was odd not giving the usual greetings with a friend and keeping distance during social interaction. Almost feels rude it’s a weird feeling. You almost have to say “sorry I can’t touch you” so you don’t seem rude lol. Unusual times we must adjust to. 
 

Anyway. At DSR I have been kinda working an area that has been rewarding me over and over. Either I’m working a productive interval OR I am simply working an area that is easy to flip slabs therefore yielding more specimens. To actually know I would have to dig seriously at different levels and see what I find. 
 

There was actually and obnoxious amount of talus on top of this and I had to rake with a purpose to get it cleared up. 
 

FIRST slab I pulled up....do you see it? 
 

Same picture zoomed in a little....see it now? 
 

Same picture zoomed in more...see it now? 
 

I wiped off some mud and took another photo....this is why phyllocarids get missed. They don’t really pop when you first find them. I scour every rock very carefully and even then they aren’t exactly jumping out of the shale. I’ve found some of my BEST specimens in other peoples garbage piles. I’ve have found spectacular specimens this way. 
 

I knew I had a beautiful Rhinocaris double carapace and I could see something curious sticking out the end but I wanted to clean it up before I made assumptions on my observations. 

 

I actually found several phyllocarid specimens on this day  . I’m going to share some of the process I go through cleaning and cutting choice specimens and show the final results!

 

stay tuned 

[Al Tahan]

I only reduced the slab a little bit in the field. I now have a table saw to deal with samples I’m afraid to break down so I took home a nice chunk. 
 

I always wash the mud off then cut. I actually found 2 other phyllocarid partial carapaces after cleaning this slab. 
 

 

This is bound to make some people cringe. Depending on the shale you are dealing with this is an absolute specimen DESTROYER. Some shales just can’t deal with this and they will crumble. The DSR shale is more of a silty shale and the only real issue is the unpredictable nature the rock splits in. Anytime I clean a slab there are usually microcracks that show but rarely do I need to stabilize. If you just go quick and do 1 run it’s fine. I imagine repeat trips under running water would tell a different story. 
 

You can see the tiny cracks as the slab dries off. Check out the phyllocarid!! This is when I started to get excited. 
 

I asked for a tile cutter for Christmas for this reason. Takes maintenance because I’m using this for shale and it produces a lot of mud where tiles do not. So I have to clean it out pretty thorough after each use to keep the life for as long as possible.

totally worth it. I absolutely recommend a tile saw for small cuts and reducing slabs to aesthetic looking display pieces. It’s very satisfying. 
 

Such a satisfying piece. 
 

Now some close ups and some more phyllocarid finds!! I actually found another quality specimen. 

[Al Tahan]

This piece right here really blows my mind. I know I’m looking at a phyllocarid double carapace and I’ll eat my hat if that’s not a telson on one end. Or we may be looking at

some freak luck?....and it’s something unknown coming out the end? I think it’s gotta be a telson. It just looks a little different from what I would expect. I’ll elaborate a little more later. 

 

I cut this one up nice too. The counterpart is quality so it also got the special treatment! 

Here is a close up. The other carapace is stuck under bedrock but it’s prolly there or at least part of if is.

 

 

It really looks like 2 body segments with a possible buried telson present right next to the carapace. This screams “I need prep” so bad. Ugh...I envision a beautiful double carapace with a disarticulated telson in frame. 
 

This was an interesting find. It was a perfect single carapace on a large rock. I took 1 whack and it split terribly but....

 

Continued 

[Al Tahan]

It split showing that the other carapace was folded over. First time I’ve found one like that. It did not hint at being a double and folded so I wonder how many more I have that are like that. 
 

here is a nice little partial Rhinocaris. 
 

Here’s my only trilobite find from DSR. It also got cut cause I didn’t want to deal with the large rock for a small specimen. 
 

COLE HILL FINDS:

I also visited Cole Hill but only for a short time since I was pretty drained from DSR. 
 

I found a crushed roller!!! I’m not sure if the pygidium is there cause nothing is exposed on the underside of the rock. I lost the eye unfortunately . I tried really hard to find it. I was not in the counterpart which I kept. Sometimes these things happen. On the bright side check out the greenops association!! How lucky! Still a neat piece despite it missing the eye
 

I only took a few other things home with me from Cole Hill. 
 

 

ok lastly just a few comparisons photos and a conclusion!! 

[Ash]

Nice finds! I wonder if any of our resident prep guys would be so kind as to clean up the trilobite for you?

[Al Tahan]

I’m just going to make observations here and only that. Due to my lack of ability to find information on Rhinocaris columbina phyllocarids from the middle Devonian I’m only left to a couple sources. 
 

Here are the 2 best diagrams I could find of Rhinocaris. The lower photo is from James

Halls Paleontology of New York: trilobite and other Crustacea. The top is from John Clark.

 

 (Clarke, John M. “On the Structure of the Carapace in the Devonian Crustacean Rhinocaris; and the Relation of the Genus to Mesothyra and the Phyllocarida.” The American Naturalist, vol. 27, no. 321, 1893, pp. 793–801. JSTOR, www.jstor.org/stable/2452130. Accessed 1 Apr. 2020.

 

Clark’s diagram came later on and I’m guessing he had better specimens to go from so there are more details. 
 

This is a complete Rhinocaris columbina found at Geer rd quarry in 2010 by a well respected collector in the paleontology world. I forgot I had this buried in my phone. Hard to deny what is in the photo. Looks very legit. 
 

Here is a disarticulated specimen I found last October. The telson is to the right of the carapaces. 
 

Close up on the telson of that October specimen. 
 

I found this Rhinocaris a few weeks back. Definitely has some body segments going on and the telson is probably buried. Take note that this phyllocarid DOES have that slight grove in the carapace seen in John Clarke’s diagram. I see them present on some specimens and not on others. I do not know why. 
 

 

Then we have this one. Call me crazy but it’s not exactly what I was expecting when I found my first complete (I figured it was possible at DSR) 

 

Here is a close up with some telson details. 
 

 

Here is a little mash up with comparisons. In my honest opinion I want to say I’m looking at a complete phyllocarid however it does contrast a little with other specimens I have found and have seen from others. Maybe the body segments and telson could be disarticulated and partially under the carapace. James halls book lists 2 species of the genus Rhinocaris. Rhinocaris columbina and Rhinocaris scaphoptera however the latter is described with basically scraps and partials. I invite anyone on the forum offer their opinions! I am open to ideas. 

 

I hope you enjoyed and thank you for reading   

 

Al

 

[Tidgy's Dad]

Fascinating thread, fascinating creatures. 

Breathtaking finds. 

Thanks for sharing. 

[Peat Burns]

[Huntonia]

Hey, that roller is still pretty awesome! Looks like the remaining shell has some nice detail. I'd be over the moon with that, however I really love homalonotids. Nice finds, some great phylolocarids!

[Wrangellian]

^ what those two said!  I'm envious of anyone who has access to phyllocarids and similar things.

 

I also appreciate your description of trimming and seeing your setup. I need to get a tile saw. The chopsaw I'm using is not ideal, but it works for some stuff. I just wonder how big a chunk a tile saw can take...

I agree with trimming large chunks with small fossils, but I'm glad to see you're not trimming them too close.

You're right about shale - my local stuff just does not hold up well under water, at least not if it has had even a little bit of weather exposure up there at the site, and when it does get wet and starts to dry, those cracks show up as in your example. If I excavate deeper into the rock, that stuff holds up a little better, but still I want to be careful and keep water off it as much as possible, especially before soaking glue into the cracks.

 

[Al Tahan]

@Wrangellian I have definitely learned from my silly mistakes with over trimming in the past ....I have since learned to appreciate the matrix as part of the picture! The tile saw can handle chunks about 3 inches thick and I’ve cut some large slabs as long as it’s not to thick. Really a treat to have I highly recommend. It’s a wet saw so depending on matrix it may not be a fan of that. I’ve done a couple dry cuts but yikes it basically caused a breathing hazard on the basement!!! I do want to get a saw for field cuts eventually for when I can’t get a specimen free of the bedrock. 

[Fossildude19]

A few more images for your perusal, Al. 

Great phyllocarid finds, my friend.  

 

Also a neat paper on a new Tropidocaris

   

 

   

[Al Tahan]

Thanks @Fossildude19 I’ve been looked at the Lindsley source and Carl Wilson source and I kinda think it’s 1 of 2 things. I’m in the Rhinocaris train or the Elymocaris siliqua train. Only thing is the Elymocaris in James halls book is from the Chemung group in Pennsylvania. I guess the really shortened telson is getting me confused and or unsure of the ID. Maybe I’m just too picky over details? 
 

 

@Tidgy's Dad thanks!! 
 

@Huntonia I have to agree with you...I really want to get a Moroccan homalonotid someday 

[FranzBernhard]

Just !

 

And you are already my fossil hero of the year because of this:

6 hours ago, Al Tahan said:

I’ve found some of my BEST specimen in other peoples garbage piles. I’ve found spectacular specimens this way. 

Nothing else to say! 

 

Franz Bernhard

[Huntonia]

2 hours ago, Al Tahan said:

 

@Huntonia I have to agree with you...I really want to get a Moroccan homalonotid someday 

Indeed, I was fortunate to snag a small curled Wenndorfia off the auction site, to this day it is still one of my favorites and I'd love to get another. I've also been dying to add a calymenella to my collection but so far no dice. Happy hunting, keep it up!

[Wrangellian]

6 hours ago, Al Tahan said:

@Wrangellian ....I have since learned to appreciate the matrix as part of the picture!

That's what I'm saying!

I've been cutting dry but I have the luxury of doing it outside. Just too nervous to use water on this shale. I've got a wet/dry blade so I know it's OK to cut dry, but it's slow going, I think because of the chop-saw setup - it really needs to be a linear type like a table saw or radial arm, like those tile saws. Someday I'll have one!

[t-tree]

Great finds  and location photos.

John

[Monica]

Amazing stuff, as always, Al!  Your full forum name should be "Trilobite/Eurypterid/Phyllocarid Enthusiast"!!! 

[Jeffrey P]

Congratulations Al! More superb Rhinocarid specimens to add to your already awesome collection. Thanks for sharing. 

[Fossildude19]

10 hours ago, Al Tahan said:

I guess the really shortened telson is getting me confused and or unsure of the ID. Maybe I’m just too picky over details? 

Keep in mind, the rest of the telson tips and body end could be under the shale/valve of the phyllocarid.

That one Rhinocarid  (in your example pics) with the long telson looks odd, to me. 

[Al Tahan]

@Fossildude19 I’m thinking you are right. I also wondered if the telson looked short cause it was tucked under. Seems like a very likely scenario. I needed some other opinions, thanks for the input tim . 
 

thanks!! @t-tree @Monica @Jeffrey P

 

@FranzBernhard ha thanks! The disarticulated specimen I found in October was a garbage pile picking. I also have 2 beautiful Echinocaris specimens from junk piles that weren’t in the post......kinda crazy! 

[DrDave]

Home run of a day out, home run of a find with that complete Rhinocaris plus telson, home run of a post!!!