Adam's Ordovician.

[Tidgy's Dad]

On the reverse are some nice Flexicalymene cranidia. 

This one's 1.2 cm wide: 

This one 7 mm across :

And this one 8 mm:

And a really tiny bit of pygidium, 2 mm across ;

[Tidgy's Dad]

An Isotelus thoracic segment? 

Isotelus? 

[Tidgy's Dad]

From the Lawrenceburg road cut, Indiana, from slightly earlier in the Cincinnatian, also thanks to Ralph, I have a few little trilobits.

Anyone want to make any guesses as to what they are exactly, please feel free. I posted some of them in Fossil Id. a while back and received some good thoughts but nothing definitive. 

This first one is pretty small, about 2 mm 'tall'. 

And another similar thingy, scale in mm:

After a bit of pin work : 

The one below is about 3.5 mm long.

After some fiddling: 

And a bit more poking : 

Maybe something similar, near the centre top of this next picture?  

And a free cheek and spine or 'splintered' border of cephalon below? 

Genal spine?

And a little thorax segment :

 

 

[Tidgy's Dad]

WOW! 15,000 views for this thread. 

Makes it all worthwhile when I get the views, comments and informative posts. 

Thanks very much, everyone, and I have nearly finished Adam's Ordovician . Just a few echinoderms and a graptolite to go. 

Speaking of which, I read a very interesting paper recently, discussing how crinoid columnals are generally dismissed as a means to identification, but they shouldn't be summarily ignored.

Crinoid Columnals.pdf

So, i have been studying the columnals found in the Cincinnatian. 

Here, from Lawrenceburg, are some Iocrinus subcrassus, the only species found there with pentalobate or stellate stem sections : 

The rounded ones with a small lumen are most likely Ectenocrinus simplex..

[jpc]

15,001.  

[minnbuckeye]

15002, hope to see it at 30,000. Funny how a thread originating in Morocco helps me to ID so many things that I have found. Hope Forum members keep sending you more specimens!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Tidgy's Dad]

2 hours ago, jpc said:

15,001.  

Thanks, JP! 

Though you were about 15,065, unless you popped in a bit earlier as well. 

2 hours ago, minnbuckeye said:

15002, hope to see it at 30,000. Funny how a thread originating in Morocco helps me to ID so many things that I have found. Hope Forum members keep sending you more specimens!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Thanks, Mike!  You were about 15,070, this old thread is rattling along!

I'm glad it's been of some use to you. The other day I had a request for a link to my Silurian page, as someone had found it very useful for identifying fossils from the Wenlock limestone in the UK. I love doing research on the fossils I receive, though I'm not sure I'm always right. Sometimes, hopefully 

Yes, Forum members have been very kind to me, and i would still be immersed in Ordovician stuff if it weren't for this Covid pandemic making it too expensive or impossible to send parcels from the USA or Canada to Morocco. I had three parcels of Ordovician stuff all ready to be posted to me, but no dice. 

Still I have a parcel from Bulgaria waiting at my local post office, so some things are still getting through. 

And frankly, my postal problems are nothing compared to the job losses, isolation and tragedies that have befallen too many people this year. 

I am consider myself pretty fortunate. 

[Tidgy's Dad]

Another common crinoid columnal found at Lawrenceburg is Ectenocrinus simplex. This actually has two types of circular columnal; larger ones with a smallish lumen, wide sunken alveola and rounded crenularium that also has a rounded latus, and smaller ones that fit in between the larger ones, resting in their alveolae. These smaller ones have typical symplectial articulation and a flat latus. 

Some examples are shown above, here are a couple more : 

    

[minnbuckeye]

29 minutes ago, Tidgy's Dad said:

my postal problems are nothing compared to the job losses, isolation and tragedies that have befallen too many people this year. 

SOOOOOOOO true. I consider myself lucky not to have experienced anything life changing through the epidemic, but know many who have.

  

Mike

[Tidgy's Dad]

This is a third easily identifiable crinoid columnal from Lawrenceburg - Cincinnaticrinus varibrachialus. You can see the five oval, petal-shaped impressions on the articulating surface quite clearly in this specimen ( 4 mm diameter) : 

 

 

[Tidgy's Dad]

The last of my fossils from Lawrenceburg was a great and very pleasant surprise, found whilst I was pin prepping a large Rafinesquina ponderosa to more clearly reveal its numerous Petrocrania scabiosa epibionts. Here it is top left before prepping : 

And then after most of the pinwork was completed : 

Don @FossilDAWG spotted it immediately, of course. It's a rather lovely edrioasteroid; Carneyella pilea. 

The brachiopod is about 5.4 cm wide and the edrioasteroid 1.5 cm in diameter. 

You can see the three plates that cover the mouth where the ambulacra join very clearly in some of the photos. 

After some more poking : 

Showing some detail of the peripheral rim : 

Mouth plates :

Peripheral rim : 

Lateral view : 

 

[Tidgy's Dad]

So, that's it for my Lawrenceburg specimens. A huge enormous thank you to Ralph @Nimravis Thanks to you I have thirty species from this site! 

WOW! 

[Tidgy's Dad]

Back to my favourite hash plate from St. Leon and a look at the crinoids stems. 

The first one is very distinctive as it has , very unusually, square stem sections. Xenocrinus baeri. It is also the most common crinoid in the piece and points to it being from the Liberty Formation, rather than the Waynesville, as I had originally suspected. 

These are tiny, only 1-2 mm. 

All the columnals of all species are not articulated in my various pieces from St. Leon. 

 

[Tidgy's Dad]

Then we have the petal pattern of Cincinnaticrinus again, but a different species, this is C. pentagonus. 

They're a bit bigger, up to 5 mm in diameter. 

[Tidgy's Dad]

Just 1 to 2 mm again for Gaurocrinus nealli. 

These columnals are pentagonal but have very rounded corners.

On some specimens the corners project, but remain rounded :

[Tidgy's Dad]

Plicodendrocrinus casei has much more stellate columnals. 

[marumo]

Thank you so much for posting these! Honestly, you have some really beautiful and exciting samples!

[Tidgy's Dad]

1 hour ago, marumo said:

Thank you so much for posting these! Honestly, you have some really beautiful and exciting samples!

And thank you for your kind comment. 

[Tidgy's Dad]

There are also round columnals, but these could belong to several species. 

And that's it for the wonderful hash plate and for the St. Leon road cut. 

17 species on the hash plate alone! 

So, yet a further huge thank you to the super generous Ralph @Nimravisfor these as well. 

 

[Tidgy's Dad]

Of course, telling crinoids apart just from the columnals is not always possible. 

For example, here are three pieces of the crumbly mudmounds of the Boda Limestone, Late Ordovician from Rattvik, Sweden, sent to me by the canny @Kasia

It is thought that fifty or so species of crinoid and several cystoids are found in these deposits, but only a couple of species of the crinoids have been formally classified. It seems that the bigger ones lived mainly near the centre of the mudmounds with some smaller ones among them, but getting the species get smaller towards the edges of the mounds where most of the cystoids also are to be mostly found. 

I decided to keep one of the rocks as intact as possible, but the others, being mostly very crumbly with some hard lumps, I decided to carefully bosh with Harry the Hammer and see what I could separate. Apparently, the area nearby suffered a meteorite strike further adding to the smashing up of the rocks. 

Here are the crinoid bits that I extracted, the biggest is 1 cm in diameter, the smallest about 1 mm. Most were single columnals but some were articulated, the longest section being 2.5 cm. 

Close ups of a few of the columnals : 

 

 

[Tidgy's Dad]

Then there are a lot of tiny cirri, often only about a mm wide :

A branching arm :

A cystoid or crinoid calyx? 5 mm tall. 

 

[Tidgy's Dad]

Even better, hidden deep within these crumbly rocks I found some brachiopods! 

Yaaaaaaaaaaaaaayyyyyyyyyyyyyyyyyyyyy!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

So, I smashed up the last rock as well and found a little bivalve, I think. 

 

 

[Tidgy's Dad]

The smallest one is a little strophomenid, about 7 mm wide. Leangella longae.

Really difficult to get a decent photo, I'm sorry to say.

This is the quite long trail. 

Very fine costae.

h

Posterior view : 

Beak (and a crinoid columnal) :

[Tidgy's Dad]

A little bivalve, about 7 mm wide :

Hinge. And another crinoid columnal. 

 

[Tidgy's Dad]

Another strophomenid, Eoplectodonta rhombica. 

The maximum width of the brachiopod is 8 mm. 

Note the few thin widely spaced ribs.