Adam's Ordovician.

[FossilNerd]

9 minutes ago, Tidgy's Dad said:

Thanks, Wayne, very nice specimens. 

The big one is a really decent size and judging by that and the relative equality of size of the striae, would be Rafinesquina ponderosa. The one on the right, too, probably.

The stacked ones are R. alternata. 

 

Glad I could contribute Adam.  

Thanks for the species correction. I’ve taken a quick look myself and would agree.  

[Tidgy's Dad]

There are also orthids present in the Bon Well Hill Waynesville Formation material. Orthids and strophemenids dominate most Ordovician brachiopod faunas, it seems. 

These are Cincinnetina meeki which I also have from St. Leon. They often occur in layers with thousands of specimens. 

The one bottom row left is a near perfect articulated specimen. Beautiful.

The pedicle valve is quite convex and has a clear ridge down the middle. 

The brachial valve is marked by a distinct sulcus and is convex, but only a little. 

The second specimen, the one bottom right, is just a brachial valve :

The median septum (ridge), adductor muscle scars and hinge teeth are very clear. 

The specimen in the bottom row middle is rather large for this species at 2.2cm wide :

Here are the two in matrix :

 

 

[Tidgy's Dad]

Vinlandostrophia is another orthid that appears commonly thoughout the Cincinnatian.

The Waynesville Formation contains a lot of species, at least eight, but it is usually possible to distinguish them from external morphology based on the number of costae in the sinus, on the fold and on the flanks, the size and shape of the costae and shell and so on. 

Here's two specimens from Bon Well Hill : 

 

The more rounded one on the left is Vinlandostrophia  laticosta. It has three ribs in the sulcus on the pedicle valve and the central one is stronger than the two on the flanks. It has seven plications on the flanks. 

A clear delthyrium (opening)  on both valves : 

 

[Tidgy's Dad]

The 'winged' shape of the specimen on the right in the photo at the start of the last post is known as acuminate. Hence the name of this species Vinlandostrophia acuminata, though other species are acuminate also. V. acuminata has three plications in the sulcus, all are weak, the lateral ones more so than the central one. It has between 7 and 10 plications on the flanks and is flatter than some other species. 

Unusually, this is only the pedicle valve, Vinlandostrophia has strong articulation so is most often found with both valves still joined together, but here we can see the inside of the pedicle valve, which I think is the first lone valve I have for this genus. 

This specimen sadly arrived broken into three pieces, but I have glued it back together. Badly.  

Notice the strong teeth and very deep muscle pit.

[ClearLake]

Oh wonderful, Vinlandostrophia from the Cincinnatian!  These are a great brachiopod and also a bit maddening. Formerly Platystrophia (for the old timers out there) these are a very robust brachiopod and therefore quite common at many of the area outcrops. But the literature on these can just be a mess to read as there is so much gradation between many of the named species. This is one of those genera where lumpers and splitters can argue until they are blue in the face!  I just spent last week going through a bunch I collected last year and I don’t know whether I’m more confused or less on how to tell them apart.  So I’m looking forward to seeing more if you have them as you do good job of detailing the differences. I have found several publications that go through the differences, but it all gets a bit messy when you have a pile 50 sitting in front of you -haha!!

[Tidgy's Dad]

6 hours ago, ClearLake said:

Oh wonderful, Vinlandostrophia from the Cincinnatian!  These are a great brachiopod and also a bit maddening. Formerly Platystrophia (for the old timers out there) these are a very robust brachiopod and therefore quite common at many of the area outcrops. But the literature on these can just be a mess to read as there is so much gradation between many of the named species. This is one of those genera where lumpers and splitters can argue until they are blue in the face!  I just spent last week going through a bunch I collected last year and I don’t know whether I’m more confused or less on how to tell them apart.  So I’m looking forward to seeing more if you have them as you do good job of detailing the differences. I have found several publications that go through the differences, but it all gets a bit messy when you have a pile 50 sitting in front of you -haha!!

Yes, I have Platystrophia / Vinlandostrophia from the Decorah Shale and onwards detailed on and off throughout this thread. Although all the North American Upper Ordovician species have been assigned to Vinlandostrophia, I can't find confirmation that some of the Middle Ordovician species have been reassigned, some probably not as they also occur in Europe where the genus Platystrophia is still valid. 

I have : 

Platystrophia amoena - Decorah Shale.

P. biforatus - Cummingsville. 

Vinlandostrophia hopensis Fairview Formation, Mt. Hope Member.

V. crassa - Fairview Formation, Fairmount Member

V. laticosta Mount Auburn Formation and Waynesville Formation.

V. ponderosa ponderosa from several formations.

V. acutilirata Liberty Formation and Lower Whitewater Formation

V. acuminata Waynesville Formation 

and the related Siljanostrophia jaanussoni) from Sweden. (now probably Neoplatystrophia).

I also have further specimens from the Whitewater Formation to examine, but I think may include V. cypha.

There are lots more for me to get my mitts on yet, and at some point, when I have the majority of the more common species, I must do a separate thread outlining the differences in hand sample where this is possible. 

 

[Tidgy's Dad]

This one's a slightly battered separated pedicle valve full of matrix but it's a monster! 

Hebertella occidentalis, I think, but I've never seen one this big.

Long, broad, strophic, triangular interarea with large delthyrium. 

 

Shallow sulcus :

Close up of delthyrium :

Strong costae start at the beak: 

And split as the shell grows :

More and more as they near the anterior. 

 

 

[FossilNerd]

2 hours ago, Tidgy's Dad said:

This one's a slightly battered separated pedicle valve full of matrix but it's a monster! 

Hebertella occidentalis, I think, but I've never seen one this big.

Wow! If it is an H. occidentalis it’s a whopper!

 

I’ve looked in my collection a bit to try and confirm your ID. I think you are on the right track. I don’t have any quite as big as yours, but I have a couple of large ones that just touch the 4cm mark. None of mine are from the Waynesville. Although, you think I would have some. It is MY formation after all! Ha! 
 

Does the end of the valve curl up any? Like shown in the Commissure View on the below example from Peat Burn’s collection. I know the pedicle valves can vary, but most of mine seem to have a sharp upward curl to the commissure on the pedicle valve at the sulcus.

 

 

[Tidgy's Dad]

1 hour ago, FossilNerd said:

Does the end of the valve curl up any? Like shown in the Commissure View on the below example from Peat Burn’s collection. I know the pedicle valves can vary, but most of mine seem to have a sharp upward curl to the commissure on the pedicle valve at the sulcus.

It does curl a little, but not a huge amount. But parts of the anterior edge are missing and I believe the specimen has been slightly compressed. I have other Hebertella occidentalis with fairly flattish pedicle valves. 

[FossilNerd]

18 minutes ago, Tidgy's Dad said:

It does curl a little, but not a huge amount. But parts of the anterior edge are missing and I believe the specimen has been slightly compressed. I have other Hebertella occidentalis with fairly flattish pedicle valves. 

Then I would agree with an ID of Hebertella occidentalis.  

[Tidgy's Dad]

9 hours ago, FossilNerd said:

Then I would agree with an ID of Hebertella occidentalis.  

To absolutely confirm it, I'd really like to see the internal structure, particularly the muscle scars, but unfortunately the valve interior is full of hard matrix which would be difficult to remove and risk damaging the specimen. 

On the plus side, there is in the matrix what I think from the small size and closely packed ridges is a specimen of Tentaculites stirlingensis. If so, this is my first Cincinnatian Tentaculites and thus the oldest in my collection, another gap filled. 

What is showing of it is 6 mm long.

You can just about see that the end seems hollow, not like an echinoderm stem.  

[Tidgy's Dad]

Lastly from Bon Well Hill I have this nice little Cyclonema bilix, with most of the shell. Most of the Cincinnatian gastropods had aragonitic shells which didn't preserve so you find them as internal molds, but Cyclonema had a calcite which did often preserve. 

It's about 1.9 mm tall and the same across the base.

[FossilNerd]

10 hours ago, Tidgy's Dad said:

To absolutely confirm it, I'd really like to see the internal structure, particularly the muscle scars, but unfortunately the valve interior is full of hard matrix which would be difficult to remove and risk damaging the specimen. 

I can understand that. It's rather annoying that many brach species (and a lot of other organisms for that matter!) have some of their diagnostic characteristics on the inside. Too bad we can't just have them open up and say ahh! 

[Tidgy's Dad]

Another new location for me.  This is Garr Hill, which is a bit north of Bon Well Hill and east of the Brookville reservoir, Indiana. 

The formations here are the top of the Waynesville, the Liberty, the Whitewater and the Saluda. Most of the fossils seem to come from the Liberty and Lower Whitewater. 

A great big thank you once again to Ralph @Nimravis for sending me these excellent specimens from a different location.

 

The two corals are Grewingkia canadensis. 

 

First specimen:

Second specimen :

 

[Tidgy's Dad]

While I was prepping the brachiopods, I did manage to separate a few nice little bryozoan bits and this Xenocrinus baeri columnal which means the rhynchonellid it broke off must be from the Liberty Formation as this square stemmed species only seems to occur in the one formation 

This is the biggest of the bryozoan bits at  11 mm long. It has numerous broad, low monticules :

The others are tiny fragments, 1 to 3 mm wide.

[Tidgy's Dad]

Here's some Strophomena planumbona from Garr Hill :

This one's a pedicle valve interior, width 32 mm.

The flat interarea only occurs on the pedicle valve in this genus. Notice the delthyium and the triangular plate or symphytium that covers most of it. This is often broken off. 

Anterior view :

Second specimen, 27 mm wide :

Third specimen, 25 mm wide.

Tiny rhynchonellid near the hingeline : 

The final specimen is a brachial valve of which I don't have many, it's usually pedicle valves. It's 24 mm wide.

There's too much hard matrix on the interior to fully prep, but here's a close up of the hinge area showing the strong teeth.

 

Some more bits of bryozoan :

 

[Tidgy's Dad]

Rafinesquina alternata. 38 mm wide.

An interarea on both valves :

[Tidgy's Dad]

Most of these I think are Lepidocyclus perlamellosum. They are very similar to Hiscobeccus capax, the key differences being internal, but as the valves are rarely found isolated it is difficult to tell in hand sample. However, a general rule of thumb is that Lepidocyclus is usually a bit bigger than Hiscobeccus (2 to 2..5 cm instead of 1 to 2) and the growth lines criss-crossing the plications are stronger. 

The first one is 2.3 cm wide :

The problem with prepping this species is trying to get into the tiny gaps between the growth lines. 

If you just leave it, the detail is obscured :

But if you overdo it, the detail easily wear away :

This second specimen is 2 cm wide and the growth lines are fainter so it could be Hiscobeccus capax :

But I still think it's a Lepidocyclus that's just a bit worn down in places.

The third specimen is also 2 cm wide :

The beak is unusually incurved on this one :

And a fourth one, again 2 cm wide :

And finally, this one is 1.8 cm across which is more Hiscobeccus size and probably is one :

There is still detail, but it's much finer :

On this specimen a couple of interesting objects are stuck. is the one on the left maybe an ostracod? I thought the one on the right was perhaps a microconchid at first, but now I think a tiny crinoid ossicle with a chip out of it :

 

[Tidgy's Dad]

This one, also from Garr Hill is a bit problematic. I'm not sure, but my best guess is a juvenile Lepdocyclus or Hiscobeccus, before the fold and sulcus had fully developed. 

[Tidgy's Dad]

Three Cincinnetina meeki from the top of the Waynesville Formation, Garr Hill, Brookville, Indiana.

Second specimen :

Third one :

[FossilNerd]

I just checked in and really like your latest additions to the thread Adam. I particularly enjoy your closeup photos to show detail. Thanks for taking the time to provide them.  

[Tidgy's Dad]

Hebertella occidentalis. 

This first one is 2.6 cm wide. It was a bit squished during/ after preservation, but you can clearly see the huge fold on the brachial valve

The pedicle valve is flatter, but still convex and has a marked sulcus. The beak is not properly aligned due to the squashing.

Also a clear interarea and delthyrium on the pedicle valve : 

This is a smaller brachial valve; 2 cm wide.

This is a pedicle valve, quite large at 3.6 cm wide. Unfortunately, it broke in transit and I made the situation worse trying to repair it after a couple of glasses of wine. 

 

A classic heart shaped muscle scar : 

Interarea and pedicle opening: 

It has a very thin valve but a noticeable sulcus.

Muscle attachment detail: 

 

 

[Tidgy's Dad]

The last species from Garr Hill that I have is from the Waynesville Formation and is Glyptorthis inscultpta. They are all isolated valves between 2.1 and 2.5 cm in width.

Both valves are convex, but the brachial valve is more inflated than the pedicle valve.

First a very nice pedicle valve :

Bifurcation of ribs :

Notice that not just the more obvious growth lines, but the smaller, incremental ones produce a reticulate ornamentation.   

Valve interior :

Prominent interarea, teeth, and delthyrium : 

A

Notice the overhanging pedicle foramen above.

Close up of muscle scars below :

The second specimen i first thought was Retrosirostra, but I now thin this is also a Glyptorthis insculpta pedicle valve with the foramen broken off. the typical cross-hatching is evident. 

Couple of square Xenocrinus baeri columnals in here.

A brachial valve, quite domed and with a sulcus:

Cross-hatching :

Interior:

Another brachial valve, covered in the encrusting bryozoan Atactoporella schucherti :

Atactoporella in detail : 

Interior details :

And a big thank you once again to the marvelous Ralph @Nimravis for all these Garr Hill fossils. 

Edited April 1, 2021 by Tidgy's Dad

[Tidgy's Dad]

This next little selection of Cincinnatian brachiopods are from my great and generous friend Debra @Paleome.

They come from around Dayton, Ohio.

And this first one is from Miamisburg. 

It's Plaesiomys subquadratus and is very similar to Glyptorthis insculpta (see above post) but is more rounded and, though it may have some strong growth lines, never shows the cross-hatching between the ribs and fine growth lines that G. insculpta does. This is a lovely specimen and is another tick off of my Cincinnatian brachiopods list. 

The brachial valve is domed and has a shallow sulcus running all the way across it :

There's a bit of really tough gloop on the shell i can't remove, but generally it's pretty nice.

The pedicle valve is only slightly convex, almost flay except where there is a fold, noticeable particularly near the pedicle : 

Short, slightly curved interarea but a straight hinge lline  : 

Triangular delthyrium and cardinal process : 

Detail : 

Commissure :

Beak : 

Costal detail without fine cross-hatching : 

 Commissure does have more detail : 

 

 

Edited April 15, 2021 by Tidgy's Dad

[Tidgy's Dad]

Also from Miamisburg, Richmondian, is this Rafinesquina alternata. Or rather two or three brachial valves all sitting on top of one another.

The coarse ribs  interspersed with several fine ones :