A few crinoids

[Kane]

I preface this by saying I'm not a crinoid collector, nor someone who has the foggiest idea of how to prep them effectively. If I encounter one that looks relatively complete, I'll bring it home. I focus prep on trilobites mostly, and there is a thread where I park those.

 

It's been a busy week at the bench, and I thought I'd close it out with one finished piece, and one that is halfway done. 

 

First up is the finished piece. I didn't take a before photo for some reason, but these appear as faint traces in this material. This one is an Ectenocrinus. It already had some damage in the field up at the arms. 

[Kane]

This one may be either a Dendrocrinus or Iocrinus. I'll have to look into the literature. This one is halfway done, and boy does it like to branch, and branch again! 

 

Here is how it was when I brought it from the field:

 

 

Missing a bit of the stem, sadly. The arms are all tangled up with bits of trilobite and brachs. 

 

Still a heck of a lot more work to do. I know some people are as gaga over crinoids as I am over trilobites! I have no idea what I am doing, but just following basic prep principles. In the Devonian material I collect from, a full crinoid simply doesn't happen outside of Arkona shale, with other formations mostly having scattered ossicles. Once I can get back to the lab, I'll finish it up and post the final result.  

 

[Tidgy's Dad]

Nice work.

Those are lovely. 

[Fossildude19]

Looks pretty awesome to me, Kane!   

[Kane]

Thanks guys!  

[Jeffrey P]

I am enthralled by those. Great prep work so far. You're revealing them in all of their glory. I hope to have some like that some day. I'm guessing those are Ordovician.

[Thomas.Dodson]

Looks like a nice prep job to me. Well done, very nice specimens.

[Kane]

Thanks, gents!  

The second one is still due for a lot more love in the lab. Soon I'll be switching to straight baking soda as those arms are fragile.

And, yes, Jeffrey, Ordovician! 

[FossilDAWG]

You can put me in the "gaga for crinoids" camp.  Those two are very nice indeed!  The second one has a Dendrocrinus "feel" to me, as my Iocrinus have more robust arms close to the calyx.  However it would be good to see the calyx in more detail to be sure, as despite their superficial similarity Iocrinus is a monocyclic disparid (so the calyx has basal plates but not infrabasals) and Dendrocrinus is a dicyclic (basals+infrabasals) cladid.

 

Don

[Kane]

Will do, Don! I am not sure there is much calyx to expose on the second piece, but maybe a bit more prep and a closeup with a proper camera might help (it seems to be a small calyx). The Dendro seems more a match to me, too, at the moment.

[historianmichael]

Good work so far! I am excited to see what the second crinoid looks when you are done. Nice finds!

[Ludwigia]

I think you're doing quite well. At what rate are you keeping the pressure?

[Scylla]

Those are really beautiful

[FossilNerd]

Those are some beauties! I have a recently developed soft spot for the echinoderms.

 

Crinoid columnals and ossicles are common here, but intact crinoids (or semi intact) are rare. Great finds and great prep work, even for a trilobite guy! 
 

How big are they? I imagine the second one will be even more of a pain to prep if it’s on the small side. 

[Kane]

2 hours ago, Ludwigia said:

I think you're doing quite well. At what rate are you keeping the pressure?

Around 2 to 4 bars (or mostly at 30 PSI) just to get the bulk done, but the finer details will see the pressure drop substantially so I don't blow off the delicate parts!

38 minutes ago, FossilNerd said:

How big are they? I imagine the second one will be even more of a pain to prep if it’s on the small side. 

The first one has a length from calyx to tip of about 4 cm, and the incomplete one calyx to tip of about 8-9 cm. Seems a good size for prep! 

[FossilNerd]

58 minutes ago, Kane said:

The first one has a length from calyx to tip of about 4 cm, and the incomplete one calyx to tip of about 8-9 cm. Seems a good size for prep!

That does seem a decent size. I have a small one that is just over 2 cm. I didn't prep it myself, but I could imagine it being a pain in the neck with its small and delicate tangle of arms.

[Sjfriend]

Beautiful work @Kane even for a "trilobite guy" lol. I too am more the trilobite kind but can still love a great piece!

[Kane]

Snuck into the lab this morning to finish things up. 

 

It doesn't look all too different than how it was before, but a lot more of the smaller arms are now revealed: 

 

I do like the little straggler bits. A closeup with Ceraurus and Flexicalymene in the arm-tangle:

 

[Kane]

While hunched over the scope, why not clean up a few other pieces?

 

A jumble of Ectenocrinus crowns and stems:

 

 

Tidying up this diminutive Cincinnaticrinus: 

 

 

And get started on a Devonian one from the brutally tough matrix of the Bois Blanc Fm. This crown rests atop a huge horn coral: 

 

 

 

 

  

[FossilNerd]

 

 

 

[Tidgy's Dad]

Very nice! 

Which Formation is  the Cincinnaticrinus from, please?  

Neuville Fm? 

Edited August 25, 2021 by Tidgy's Dad

[Kane]

10 minutes ago, Tidgy's Dad said:

Very nice! 

Which Formation is  the Cincinnaticrinus from, please?  

Neuville Fm? 

You have it absolutely correct.