More Crinoids

[Guest solius symbiosus]

I went back to the same out crop today and pulled out 5 more crinoids. This time, I found the horizon, and found them in situ. The ones the other day were found in talus.

I think I have found a garden. All of them were found with in 1m of the hammer; in the clayey bed.

This one where the hammer was setting

The other ones are deep in the matrix, and I need a new stylus for my scribe. I fired the blaster up, and it makes a mess. So, I have to make a cabinet.

Though, they should prep out nice.

[Guest Nicholas]

Nice Crinoids, I know many people who make their own boxes. Usually out of plywood and any transparent plastic top.

[geofossil]

You've hit a jackpot! Quality finds of crinoids are rare. Your discovery of that horizon might be one of those 'WOW' motherlodes. Keep us posted with your finds from that site

[Uncle Siphuncle]

Congrats Soleus. I've only found one crinoid stem logjam that proved to be a bed of crowns. I think I got 12 Ectenocrinus from that site. On echinoids in limestone I often so some of the detail work with KOH when the fossils are in limestone or marl. Would this help or hurt these specimens?

[Guest solius symbiosus]

At this site, I have also been seeing some scolecodonts. I'll photo the next one I come across.

I've found at least 1 other garden, and maybe 2. In one I pulled an Ectinocrinus every time I went to the site. I collected 12 before highway construction destroyed the site. Though, I was never able to locate the horizon.

At another site, I found 6 Columbicrinus in one slab in a creek. I haven't been back to that one years, but I have always planned to go back.

The Ectinocrinus are in my warehouse, but here is a pic of the best Columbicrinus.

[Guest solius symbiosus]

I often so some of the detail work with KOH when the fossils are in limestone or marl. Would this help or hurt these specimens?

I've never used it, sounds interesting. How caustic is the stuff? What is the molarity that I should use?

[Uncle Siphuncle]

I use it in flake form. I first wet the specimen to help the flakes stick, place it in a pyrex dish, apply the flakes, then spray it with water until the flakes fizz and begin to dissolve. The flakes will then form a crust over the specimen that I like to leave in place, occasionally spraying to keep the reaction going. This is an exothermic reaction that turns limestone and marl (not sure able shale) to mud, some formations faster than others. Some calcitic fossils don't jive with it well, others do. On something delicate like a crinoid crown I'd start with columnals first as an experiment, then work on the crown with successive 10 minute applications to keep from overcooking, discoloring, and/or disarticulating the segments. When done I rinse the specimen in water while scrubbing it with a toothbrush as the KOH can often leave a gel like slime coating on the specimen. From there I drop it into vinegar for 10 minutes or so, occasionally scrubbing the vinegar in with a toothbrush. This is to neutralize the alkaline KOH. Then I soak the specimen in water for several minutes. On echinoids this stuff often reveals fine tubercles in good detail, but overcooking can make fine surface details lose definition. Experimentation is the key, starting with junk, and as always, use in a well ventilated area with hand and eye protection. I'd use this method only the matrix is too hard to properly air abrade.

[ashcraft]

Crinoids are rare? I guess it depends on where you live/collect. I see all the shark teeth posted, and am just amazed. I have only seen two found in this area, and neither were mine (sigh). On the other hand, I have a block of Girardeau limestone sitting on the table at the house that has 10-20 whole crinoids showing through the matrix, about the size of a dime.

Due to their small size, and my old eyes, I have to get a base set up for my microscope before I can prep. The crinoids are all silicified, so I use acetic acid, applied with a paint brush, and a sears engaver, for most of the work.

Someday soon I'll get a camera and show y'all.

Brent Ashcraft

[RJB]

Hey Solius. thats purty dang cool that you stumbled across some super cool crinoids! Thats one fossil Ive never found yet. You must be in heaven? Very nice specimens.

RB

[Guest N.AL.hunter]

Dan, thanks for the KOH info. I have many crinoids sitting unprepped. Crinoids is something we have in North Alabama. Some in large matrix and many free from most of the matrix. I have left them because I have never been able to successfully prep one without damaging it. I must have 50 laying around waiting. I was hoping to put together some sort of air abrasion tool. Anyways, I'll give your technique a try.

For anyone interested, the SW shores of Cedar Creek Lake/reservoir in western Bama have many crinoids laying around if you look carefully. Some are even completely weathered out. This area gets collected a lot, so turn over many rocks. Also you micro collectors out there, some areas of the shoreline is nothing but extremely small bits and pieces of stuff. Also some of the longest Archimedes I have ever seen in one piece, over 6 inches (in matrix)!

[worthy 55]

Great looking finds!!!

[geofossil]

At this site, I have also been seeing some scolecodonts. I'll photo the next one I come across.

Just curious. How large are these? Are you speaking of the jaw elements or the body itself of the polychaete worm? Are they large enough to be visible and photographed?

[Guest solius symbiosus]

They are micro, and I never mark them, so once I "move on", They are lost. Unless, I go back over the pieces(which I tried to do last night, but they are few, and far in between, and hard to spot.

They are about the size of a pin head(the sharp point), or a little larger.

[Guest solius symbiosus]

I was at the same spot today, and pulled a couple of more pychnos of the ledge. I found two weathered ones that were pretty much just the arms.

They were found about 2 meters from the others I have found, and they had fallen down to a ledge about 1/2 meter below the bed that the others were found in.

Here is a pic from the horizon(didn't focus well).I started to dig a little in to the horizon, and was able to "pop" a little(3cm) piece out that had an arm of pychnos. The arrow is pointed to where I popped the piece out.

Here is the arm.

If I could get in there and quarry, I think there are some good ones left. I'm going to bring a sledge the next trip.

[Guest solius symbiosus]

That last pic was added by mistake. It is one that I found a few weeks ago.