Adam's Ordovician.

[doushantuo]

It's quite a long thread,and I just noted the graptolites .

**explosives deleted**

[Tidgy's Dad]

On 10/17/2019 at 5:05 AM, doushantuo said:

It's quite a long thread,and I just noted the graptolites .

**explosives deleted**

Yeah, I really love graptolites, got another one to post later.

 

[Tidgy's Dad]

Back on Page 9 I posted some lovely bryozoans that Ralph had sent me from the Lawrenceburg Road Cut. 

Since then Ralph has sent me a shed load more stuff from this locality including these little has plates  : 

It's quite interesting as you can see different kinds of matrix. 

The two on the bottom left contain a few complete but very small Zygospira brachiopods and are packed with lots of bits of smashed up bryozoans, brachs, crinoid columnals and trilobits. 

The one with the big Rafinesquina brachiopod is softer and more thinly bedded but still contains bryozoan fragments.

The three on the right are a more yellow colour and though not as packed with smashed debris as the two bottom left also contain a rich variety of fossils as well as an abundance of well preserved Cincinnetina brachiopods. 

Anyway, I've been playing with my new toy, a digital microscope, also kindly gifted me by the incomparable Ralph @Nimravis and I thought some of you may be interested in the results. 

First off, on the reverse of the piece bottom right, was this, which i think is the receptaculitid Ischadites circularis : 

 

It's about 7 mm in diameter and i'm very happy with it. 

[Tidgy's Dad]

Then there are tons of fragments of bryozoa, some may be fragments of those I posted before while others are different. Very hard to id for me. 

From the bottom left piece : 

The stick-like smooth, black ones may be Batostomella gracilis, but I've really no idea. 

From the reverse of the same piece, some of the ones with larger, round zooecia with thick walls are possibly the couple of species of Peronopora found here, most commonly Peronopora vera  : 

And from the other darker grey piece:

From the same piece as the Ischadites with a tiny Cincinnetina brach : 

Some of these more ramose forms are probably Homotrypa, there are half a dozen species in the Fairmount Member alone. Interestingly, these are found in abundance in the yellow matrix but not at all in the more grey stuff, but with a sample size of two pieces it doesn't really prove anything.  

From the piece shown top right in the previous post : 

 

 

[Wrangellian]

Interesting stuff, Adam. I do love the brachs from those areas. I've got Fisherites but Ischadites is another one for my list!

[Tidgy's Dad]

15 hours ago, Wrangellian said:

Interesting stuff, Adam. I do love the brachs from those areas. I've got Fisherites but Ischadites is another one for my list!

Thanks, Eric.

I've added a lot more photos to the above post as well as a bit of extra dubious information. 

I have a Fisherites from the Galena Fm. in Minnesota, so I need to get a Devonian Receptaculites next, as i don't think I have one yet. Or something Silurian. 

The brachiopods are often marvelous, the preservation is often astounding especially considering the age of 'em. Lots more of those to come.

But for now here are some more bryozoa from the pieces above. These very thin ramose 'stick' bryozoa with oval zooecia that exit the branches at an angle are probably Bythopora dendrina. 

These occur in all the pieces.

Some are really thin. branches or another species? 

Surrounded by Cincinnetina brachs that are about 5 mm across.

A crinoid ossicle and a really weird thin long bryozoan.

With some Batostomella.

 

 

 

 

[Tidgy's Dad]

I like this one. 

Ramose, but only half a centimetre high, bifurcates at the top, though mine don't show it well, and with very well spaced apertures, this is Arthrostylus tenuis.

Only found in the grey bits in my limited sample.

 

 

[Wrangellian]

What that plethora of bryozoans, I'm leaning towards bryozoan for your Ischadites... Does it appear to be made of the same stuff, similar-sized pores, etc?

[Tidgy's Dad]

1 hour ago, Wrangellian said:

What that plethora of bryozoans, I'm leaning towards bryozoan for your Ischadites... Does it appear to be made of the same stuff, similar-sized pores, etc?

There are indeed a large number of bryozoans in the grey matrix pieces in particular, though brachiopods abound in the yellowish stuff. There are also lots of crinoid columnals from three or four species, plenty of trilobits and one or two other things that I haven't posted yet. 

The closely packed, diamond shaped apertures, the way they swirl out from the centre, the domed shape and the fact that Ischadites circularis does occur in this formation and it doesn't match any of the bryozoan species found in the formation nearly as well, has me fairly sure my id is right. But not certain.  

Here are the last of the bryozoan images :

 

 

[Tidgy's Dad]

Among all the multitude of other smashed up bits here, in the middle left is that a larval gastropod/ protoconch ? 

Less than a mm across.

[Tidgy's Dad]

Though all the pieces contained a fair number of brachiopods, I haven't taken too many photos as I have examples of all three represented species free of the matrix which i will be posting soon. 

The two dark grey pieces, which had all the smashed up bits, contained only tiny Zygospira modesta, both complete and multiple fragments. 

It is noticeable that their diminutive size and black colour is in contrast to the Zygospira that I have free of matrix from this location which are considerably larger and a pale grey colour. 

Scale in mm. 

The block with the large brachiopod Rafinesquina also contained Zygospira of the same size but preserved pale grey. 

 

The other, pale grey/ yellowish tinged pieces were packed with beautifully preserved specimens of the orthid Cincinnetina multisecta, and these erode free nicely as I have literally dozens of them, single valves and complete specimens sent to me by Ralph. But no Zygospira in these pieces. 

Scale in mm. 

 

 

 

 

 

 

 

   

 

[doushantuo]

Nice large brach photography, Adam.

Awesome finds

Edited November 8, 2019 by Kane

[Ludwigia]

That microscope appears to be a very practical new toy for you. Ralph sure is a generous fellow. Thanks for the informative posts. Looking forward to more.

[Wrangellian]

10 hours ago, Tidgy's Dad said:

There are indeed a large number of bryozoans in the grey matrix pieces in particular, though brachiopods abound in the yellowish stuff. There are also lots of crinoid columnals from three or four species, plenty of trilobits and one or two other things that I haven't posted yet. 

The closely packed, diamond shaped apertures, the way they swirl out from the centre, the domed shape and the fact that Ischadites circularis does occur in this formation and it doesn't match any of the bryozoan species found in the formation nearly as well, has me fairly sure my id is right. But not certain. 

I am far from certain, too - you could be right. (I hope you are)

[FossilNerd]

On 11/5/2019 at 6:35 PM, Tidgy's Dad said:

I've been playing with my new toy, a digital microscope

I’ve been thinking about getting a digital microscope myself, but have been on the fence about it. Seeing your pictures has made me fall right on over the other side! Great stuff! I was rather fond of the bryozoan pics... Then I saw the crinoid... Then the brachiopods...  Thanks for sharing! 

[Tidgy's Dad]

19 hours ago, doushantuo said:

Nice large brach photography,Adam.

Awesome finds

 

15 hours ago, Ludwigia said:

That microscope appears to be a very practical new toy for you. Ralph sure is a generous fellow. Thanks for the informative posts. Looking forward to more.

 

14 hours ago, Wrangellian said:

I am far from certain, too - you could be right. (I hope you are)

 

13 hours ago, FossilNerd said:

I’ve been thinking about getting a digital microscope myself, but have been on the fence about it. Seeing your pictures has made me fall right on over the other side! Great stuff! I was rather fond of the bryozoan pics... Then I saw the crinoid... Then the brachiopods...  Thanks for sharing! 

Thanks, guys. 

The microscope is a real boon, great fun as a toy, but useful and practical too. 

I try to put in a bit of effort with the bryozoa, they are so often overlooked or just recorded as 'bryozoan' or 'fenestellid', so I've had a bash at trying to id a few of them. As lophophorates and therefore cousins of the brachiopods, they deserve my respect and they're very pretty too. 

I'm very pleased with this next one, only a cm away from the Ischadites in the same piece. 

I was delighted to see : 

A Cornulites ! And this one I am sure about. It's only 1.5 mm across and about 4 mm long but it's adorable. 

There are four species known in the Fairview, C. corrugatus which grows in little clumps, though this could be one broken off, I suppose, C.flexuosus which is long and thin, C. conicus and C. minor. Maybe C. minor if anyone knows a bit about these weird creatures? 

Of course i thought about doing a bit of prepping with my pins but decided, as it's so tiny, probably fragile and that it's the only one I've got, that that would be stupid. 

Here's the result : 

 

 

[doushantuo]

Again, great photography.

Gracias, amigo.

 

Edited November 8, 2019 by Kane

[Wrangellian]

Nice Cornulites. I like those too.

What kind of camera are you using, or should I ask what software? Your pictures have that half-melted snow look of a typical cellphone photo. I gather a lot of cellphone images look this way as a result of being compressed (automatically), or perhaps the software is trying to sharpen a slightly blurry image. In any case I don't think it's your fault, it's the hardware or software.

[Tidgy's Dad]

18 hours ago, doushantuo said:

Again, great photography.

Gracias, amigo.

 

 

16 hours ago, Wrangellian said:

Nice Cornulites. I like those too.

What kind of camera are you using, or should I ask what software? Your pictures have that half-melted snow look of a typical cellphone photo. I gather a lot of cellphone images look this way as a result of being compressed (automatically), or perhaps the software is trying to sharpen a slightly blurry image. In any case I don't think it's your fault, it's the hardware or software.

Thanks again, chaps. 

I am using my new 'plugable Digital Microscope' which has the camera included.

I think I need to adjust the brightness on occasion, this is easily done. 

Now it's on to crinoids. 

I have only found isolated columnals in these pieces, not even two together let alone long sections or calyx pieces. 

But it is fortunate that a couple of the crinoids here have unique columnal designs. 

The yellow rock pieces with the Cincinnetina brachiopods seem to contain only the one type of crinoid, the most common type in the Cinncinattian, unshockingly called Cincinnaticrinus.

The species found here is C. varibrachialus with very distinctive patterning on the columnals. 

A few examples :

The grey rocks with all the smashed up bits, bryozoa and Zygospira by contrast do not seem to contain Cincinnaticrinus at all in my limited sample, but two or three other species instead. 

One of these is easy to identify as it is the only crinoid with pentagonal and star shaped columnals in the formation, it is Iocrinus subcrassus : 

The other crinoids are harder to identify but the thick walled round ones may be Ectenocrinius and the thin walled ones Glyptocrinus, but that's tentative at best.

Thick walled examples :

Flatter ones with ridges in the above photo may be Pycnocrinus or Glyptocrinus. 

 

[Tidgy's Dad]

Finally for these particular rocks, here are some possible trilobits. 

i'm not certain what they are but Ceraurus milleranus, Acidaspis cincinnatiensis, Primaspis crosotus, Flexicalymene granulosa, F. meeki and Achatella caleyi all occur in the Fairmount among others. Anyone know the trilobites here? Might be a bit difficult to tell from these teeny bits anyway, of course. 

 

A librigena / free cheek, I think. Some nice crinoid columnals here too : 

Scale in mm. 

Scott @piranha? 

Ralph, @Nimravis, recognize anything here? 

Ralph, you may like to look at the previous few posts as well, some great stuff I've found in those bits you sent me. 

Thanks so much. 

 

 

 

 

[Nimravis]

On 11/5/2019 at 5:35 PM, Tidgy's Dad said:

I've been playing with my new toy, a digital microscope,

Glad you like it Adam and the pictures look great.

[Tidgy's Dad]

15 hours ago, Nimravis said:

Glad you like it Adam and the pictures look great.

Thanks, Ralph.

Next up are the brachiopods from Lawrenceburg, and firstly these Cincinnetina mutisecta that you sent me. 

There were three or four more, but I've given a few away.

On the left are isolated pedicle valves, right are brachial valves and in the centre complete specimens.  

The question is - do I prep one or two of each, a few of each or all of 'em. 

Photos to follow in a few days. 

Or weeks. 

[Tidgy's Dad]

Okay so here are the prepped specimens of Cincinnetina multisecta from the Upper Ordovician of the Lawrenceburg Roadcut, Indiana. 

Pedicle valves : 

Brachial valves : 

Some complete specimens : 

Some close ups : 

You can see here why some of them still have some matrix in the grooves; there are tiny ridges on the shell that are destroyed with too much fine pin prepping. 

The little ridges :

Pedicle valve interiors:

Brachial valve interiors :

Lovely. 

[Bobby Rico]

I love your microscope work absolutely beautiful images.    

[Tidgy's Dad]

13 minutes ago, Bobby Rico said:

I love your microscope work absolutely beautiful images.    

Thanks, Bobby, I've just added a load more to the above post.