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Eucalyptocrinites crassus Hall Waldron Shale Formation


Ken K

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Have been under the radar a bit here on the forum, but plan to get more involved.  Talk about involved!...the specimen featured here has been sitting in my shop for a number of years.  As I prepared numerous Waldron specimens from my huge stock of unprepared material, I kept thinking and planning the preparation of this piece.  This specimen was collected from the Middle Silurian Waldron Shale Shelby County, Indiana.  The crinoid was found on the floor of a bench of Waldron Shale with only the very top of the crown exposed.  So, the crinoid was in situ.  From what was exposed I could see that the inner arms were missing.  I could see two support arms with no inner arms.  Being quite familiar with the Waldron, this is to be expected in many cases.  The high energy of the Waldron environment caused the toppled specimen to be "re-worked" by currents thus uncovering the crown and allowing for the inner arms to disarticulate from the specimen.  So, I cut the piece out with my rock saw from the exposure floor and brought it back to my lab.  The specimen broke prior to removal about 2/3 of the way down from the crown so I could see the cross section of stem so knew approximately how long the stem was.  The stems get smaller diameter as they move away from the crown.  Firstly I glued the two pieces back together with 5 minute Epoxy.  I then pulled a thin piece of Waldron Shale from my stock (I keep nice thin, clean pieces of shale I come across when collected to back specimen), carved out a depression the size of the exposed calyx andf then glued the thin piece of shale right over the crinoid slab.  I then cut the piece I glued on to the same dimension as the original slab...still with me? Lol.  Now comes the INVOLVED part I was referring to at the beginning!  I had already marked on the back side of the now sandwiched crinoid approximately where the crown was.  I then proceeded to prepare the specimen from the other side, which was the downside of the original toppled specimen.  This side would likely have remained buried and thus fully articulated...I hoped!...Once I carefully found the crown, I prepared it first and as predicted it was wonderfully intact save for half of one inner arm...Hey, I'll take it.   

 

What followed can only be imagined by looking at the picture featured below.   Hours and hours of work exposing the crown and stem with an ever watchful eye for additional taxa, very often associated with stems of the Waldron Crinoids as secondary tier inhabitants.  The most common are the Rhynchonellid Brachiopods, note how the pedicle of the brachs are facing the stem.  A couple of small gastropods and bryozoans round out the additional taxa exposed thus far.  

 

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Specimen measures just shy of 12 inches long with the stem (rule is 15 cm.)  Note the multiple scribe marks.  The specimen was exposed initially over 1.5 cm below the surface.  The marks are where I'm leveling out the surrounding matrix so the specimen doesn't sit in a trench.  This will all be painstakingly smoothed out and contoured.  Also, note the crack line through the stem towards the bottom.

 

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Close up view of the business end of the crinoid.  Despite what it looks like now, this will be a beautiful specimen once completed.  I will keep you updated on the progress.

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What a great crinoid!  :drool:

Looking forward to seeing the updates! :)  :popcorn:

    Tim    VETERAN SHALE SPLITTER

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"In every walk with nature one receives far more than he seeks."
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Tidgy's Dad...Thanks 

 

Hey Tim, appreciate that. It is one of the better crinoid pieces I have collected from the Waldron.  Hard to get nice specimens with most of the stem and inner arms.  Will be well worth the time and effort spent preparing it.  Did a bit more work on the matrix and will have an update in a week or so.  Thanks for following along...Ken

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Here is a quick update on the preparation of the Waldron E. crassus.  Since the previous post I cut the slab down just a bit to better showcase the specimen.  I also have completed the rough landscaping of the matrix in my shop with a Chicago Air Scribe.  I then used my Arrow scribe to further smooth the matrix and then used my air abrasive machine to finish the matrix just around the crown to see how it was going to look.  I will then be carrying out the final matrix woirk on the entire piece, which will be quite time consuming.  This needs done before the final preparation on the crinoid and brachiopods and other taxa, so as to limit the abrasion of the specimen while doing the matrix work...more later...Ken

 

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Specimen slab cut down a bit further and rough matrix landscaping completed.

 

 

 

 

 

 

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IMG_9250.thumb.jpg.abaa4d9f63bf75813cf25b1f24d580c3.jpg

 

Close up view of the crown.  Note the darker ring around the crown.  This is the final matrix work that smoothes the matrix and takes out all the tool marks.

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great work so far^_^, the surrounding rhynchonellids really bring it to life as well, i think i speak for everyone here when i say i look forward to seeing the finished specimen :popcorn:

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Thanks Will and appreciate your comments here.  The associations of other taxa together in the Waldron is one of the big reasons I got hooked on this formation and its fossils.  I will keep you posted on the progress.  despite there being a great deal of work yet to go, this one is on top of the "pile" !   Ken

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Got some work done today on the crinoid but not ready to post the progress yet.  I decided to rough out a couple of other Waldron specimens.  The first one is a terrific specimen of the brachiopod Meristina maria, Hall.  This is a good sized species with this specimen measuring almost 3cm wide.  Although common and conspicuous in the Waldron, securing perfect and undamaged specimens is difficult.  Often the shell flakes off and sticks in the surrounding matrix.  The specimen featured here was roughed out with the air scribe then air abrasive with dolomite at a medium pressure and powder flow to this point.  The remainder of the prep will be under low pressure and flow to retain all the fine detail.  The second picture is two enrolled Maurotarion christyi, (Hall).  As with the brachiopod, final preparation will be with low pressure and flow with the air abrasive.  Will update on these specimens which I should finish up tomorrow...more later, Ken

 

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Thanks rew.  As I continue to prepare this guy it's turning out quite nice and will have the longest stem of any specimen I have in my collection.  The matrix work, as expected,  is turning out to be the big time consumer here as almost all of it contained tool marks which was unavoidable in order to fully expose the specimen without it being down in a trench of sorts.

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Here is the finished Brachiopod, Meristina maria, Hall.  The trilobites are done and more progress made on the crinoid...more laterIMG_9339.thumb.jpg.3d558be9cb8dafcca1e06cec55bcadc8.jpg

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I'm closing in on having the crinoid finished.  In the mean time, I decided to post the next specimen I'm going to be preparing.  The following is a wonderful plate from the Waldron Shale measuring 17 cm x 23 cm.  There is a perfect Calymene beviceps (3cm) nestled in between a couple of bryozoan colonies.  In addition there is a root system, a couple of brachiopods and the rarely perfectly preserved bivalve; Pterinea brisa, Hall (lower right).  I have started the rough preparation with the root system scheduled to take most of the time involved in the prep work.  Should prove a wonderful piece.

 

IMG_9346.thumb.jpg.65cef1598af8e39a23249547016d6240.jpg

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Great work! Love the crinoid but like the trilobites more (ok, I'm partial since trilobites are my favorites lol)

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Sjfriend,

 

Yeah, I would have to say I'm more partial to the Trilobites as well.  However, my main interest of late is of course the Waldron, all taxa...Thanks for the note, appreciate it.  Ken

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So far so good. I usually like trilobites more myself, but that is a heck of a crinoid! I wish the limestones here in my area had complete intact crinoids with all the parts. I'm happy to find a complete, non crushed/ compressed calyx! That Meristina maria prep is nice too, I like how you left it atop the shale.

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Thanks Jackson g, I like to prepare specimens, like the brachiopods, on their original matrix most of the time.  Firstly, there is usually additional taxa on the same piece, like the Meristina specimen here.  Secondly, it provides a nice means for display.  Now in a series of the same species I like to prepare and display as follow:

 

- Several really nice loose specimens displayed on acrylic bases.

- A growth series of loose specimens (ie the brachiopods and gastropods lend themselves for growth series) displayed on acrylic bases.

- Finally, choice matrix specimens

 

I'll target one particular species and go through my stock of unprepared material and pull out all the really good specimens and start in.  Doing that with the brach genus Meristina right now.  Constantly rearranging the displayed material in my cases...but that's fun stuff!

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18 hours ago, Ken K said:

A growth series of loose specimens (ie the brachiopods and gastropods lend themselves for growth series) displayed on acrylic bases

Can't wait to see this!  I have always been a fan of growth series both in fossils and beach shells.  Your prep work is outstanding!  I looked at the pictures under your profile and your prep and display setup are drool worthy -haha, very nice!!  Looks like it would be a great "museum trip" in your area!

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Hey ClearLake,  

 

Thanks for the kind words.  I'm with you on the growth series, brings a whole different perspective to the various species.  Welcome to stop in and view the collection if you are ever up this way...once the dust settles of course!  

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Beautiful work! :drool: 

    Tim    VETERAN SHALE SPLITTER

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__________________________________________________
"In every walk with nature one receives far more than he seeks."
John Muir ~ ~ ~ ~   ><))))( *>  About Me      

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During the initial stages of preparing the Calymene breviceps plate illustrated above, I came across the disarticulated remains of an exceedingly rare Waldron trilobite Acidaspis fimbriata, Hall.  I have actually collected several complete and nearly complete specimens of this trilobite. Although undoubtably an Odontopleuridae,  I'm not convinced as to its affinities with the genus Acidaspis (keep in mind I'm no expert on trilobite taxonomy!).  It is however, the trilobite that was described by hall.  In the photo this diminutive trilobite is identified by the fimbriate free cheek, thus the species name.  A few other parts are in the same vicinity.

 

On with the prep work...

 

IMG_9380.thumb.jpg.7cb800769acc25c7db403b432ebb6e3c.jpg

 

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