Adam's Early / Lower Devonian

[Tidgy's Dad]

I dunno?

Acrospirifer? Costispirfer? 

Would be grateful for ideas from those who collect in New York. 

Edited August 8, 2022 by Tidgy's Dad

[Tidgy's Dad]

And this little one would seem to be from the Delthyrididae. 

Probably Howelella cycloptera ? 

[FossilNerd]

On 8/7/2022 at 7:55 AM, Tidgy's Dad said:

Would be grateful for ideas from those who collect in New York. 

I got nothin, but maybe Tim or Jeff could assist? 
 

@Fossildude19 @Jeffrey P

[Tidgy's Dad]

On 8/12/2022 at 11:42 PM, FossilNerd said:

I got nothin, but maybe Tim or Jeff could assist? 
 

@Fossildude19 @Jeffrey P

Thanks, Wayne, though both Tim and Jeff's posts and galleries have been very useful to me. 

Here's a species I am sure about.

From my favourite brachiopod genus of all, here are some Lochkovian Lepataena rhomboidalis from the Catskills of New York. 

L. rhomboidalis has rather been used as a 'waste basket' taxon but it certainly seems to have been a species that was wide ranging both in terms of geography and it's time span. 

I prepped this one a tad : 

Part of the trail is nicely preserved.

This one is too fragile to fiddle with :

The hinge teeth on the reverse ; 

And this one is beginning to be revealed but is going to require a lot more time : 

 

[Tidgy's Dad]

This couple of specimens from the Catskills seem to be Discomyorthis again, though the matrix and preservation are markedly different from the specimens from the Kalkberg Formation that I have and are shown in an earlier post on the previous page. This seems to be a flaky, thinly-bedded, mid-grey shale, though I understand the Kalkberg contains shale bands? Or the New Scotland Formation? The two are preserved differently to each other as well, so there may be two different formations or members here. If anybody recognizes the matrix, I'd be most grateful for your input. 

Thank you.   

The second specimen : 

 

 

Edited August 15, 2022 by Tidgy's Dad

[Tidgy's Dad]

I put this one in the Fossil Id. thread and a had a couple of welcome responses, but I'm still really left without a definite identification. 

It's not helped by the fact that I can't even tell if it has a strophic hinge line or not. 

I'm leaning slightly toward the pentamerid Anastrophia verneuili as it looks similar to other Anastrophia specimens I have, though admittedly from a different age, country and species. 

But it could easily be one of several atrypids, athyrids or even maybe a strophomenid found in the Helderberg Group. 

Anyway, once again any help would be greatly appreciated. 

Notice the number, fairly wide spread, deep and sharp ribs that have secondary ones appearing roughly half way from the posterior to the anterior. No obvious fold or sulcus.

Not a great pic, but not high domed and with a slightly flattened top. 

 

Details of primary and secondary plications :

There's a bit of bryozoan on the reverse :

Edited August 15, 2022 by Tidgy's Dad

[Tidgy's Dad]

I must thank Jeff, @Jeffrey P for his wonderful Lower Devonian fossil gallery and his experience in helping me identify this species, the athyrid Coelospira dichotoma. 

This is from just above the Helderberg Group belonging to the Tristates Group, Glenerie Limestone Formation, where the preservation is more silicious. 

Probably thus Pragian in age, still from the Catskills in New York. 

 

1st specimen : 

Second one :

[Jeffrey P]

15 hours ago, Tidgy's Dad said:

I must thank Jeff, @Jeffrey P for his wonderful Lower Devonian fossil gallery and his experience in helping me identify this species, the athyrid Coelospira dichotoma. 

This is from just above the Helderberg Group belonging to the Tristates Group, Glenerie Limestone Formation, where the preservation is more silicious. 

Probably thus Pragian in age, still from the Catskills in New York. 

 

1st specimen : 

Second one :

You're welcome Adam. You've been a big help for me with my brachiopod IDs as well. Thanks. 

[Tidgy's Dad]

On 8/16/2022 at 12:24 PM, Jeffrey P said:

You're welcome Adam. You've been a big help for me with my brachiopod IDs as well. Thanks. 

Yup, one of the many marvelous things about this forum! 

What do you think about this one? Looks like Glenerie silica presevation to me and the colour is the same. 

I think it's a chiliidiosid, something like Xystostrophia becraftensis? 

Made more complicated by the fact that the genus has changed from Eoschuchertella and the species is not actually found in the Becraft Formation., only in the Glenerie. 

Sigh.

Edit: the name has changed again. It is now Floweria becraftensis.

 

[Tidgy's Dad]

The Lochkovian in Oklahoma is represented by the Haragan and the Bois d'Arc Formations. 

The Haragan formation is rightly famous for it's beautifully preserved caramel-coloured trilobites, but it produces some very lovely brachiopods as well. 

The following specimens came to me courtesy of my good friend Ralph, @Nimravis

Thank you, Ralph, they're marvelous. 

 

I mentioned earlier that the Orthidina didn't survive the Early Devonian, well, here's one of the last genera of impunctate orthids known from the family Orthidae which became extinct at the end of the Lochkovian, so this really is the end of the line for this ancient family. 

Here is a super specimen of Orthostrophia strophomenoides parva.  The specimen comes from Black Cat Mountain, Clarita, Coal County, Oklahoma. 

Edited August 18, 2022 by Tidgy's Dad

[Tidgy's Dad]

Next from the Haragan Formation is the rhynchonellid Sphaerirhynchia lindenensis. 

I have the genus from the Middle Silurian, but the Lower Devonian spelt its extinction.

 The specimen on the right is from the Birdsong Formation of Tennessee and came to me as the same species, but clearly isn't, though the Birdsong does contain most of the same species as occur in the Haragan and Bois d'Arc. Further investigation of this one is required. 

The Haragan Formation specimens:

The second, more squished specimen:

 

[Tidgy's Dad]

Also from the Haragan Formation of Black Cat mountain, I have this beautiful Atrypa oklahomensis. 

(Whoever did the label was possibly drunk.) 

After prep, the pedicle valve:

And brachial valve; 

Anterior detail:

Posterior detail :

 

 

[Tidgy's Dad]

Anyone who is really sharp-eyed will have spotted a tiny brachiopod shell preserved on the bottom edge of the Atrypa oklahomensis specimen shown in the second photo in the post above. I love these little bonuses. 

Perhaps the less well known of all the orders of rhynchonellate brachiopods are the Protorthida. This group were once though to be ancestral to the Orthida, but older orthids have now been found, though there may be many other species of both groups undiscovered. The first rhynchonelliform brachiopods to appear in the Early Cambrian were the orders Orthida, Protorthida and Kutorginata. The Kutorginata may be ancestral to the orthids and protorthids, but the protorthids may have evolved from another group of stem group rhynchonelliforms. 

Protorthids are often overlooked because of their small, often tiny, size and can be confused with various similar looking orthids in some formations. But they existed in many places until the Kellwasser event at the Frasnian-Famennian boundary in the Late Devonian when they became extinct like so many other groups. They actually had a burst of evolution in the Lower Devonian and reached their peak of numbers and diversity at that time. 

This one is brachial valve of Skenidium insigne and represents the last known genus of the whole order to disappear in the Upper Devonian.  As well as here in the Haragan Formation of Oklahoma, the species can be found in the Kalkberg Formation of New York.  

The specimen is 3.5 mm wide. 

 

[Tidgy's Dad]

The last brachiopod I have from the Haragan Formation of Black Cat Mountain is this athyrid, Meristella atoka. 

 

[Tidgy's Dad]

The Bois d'Arc Formation of Oklahoma sometimes seems to interlink with the Haragan Formation and other times overlies it. 

The brachiopod fauna seems to be almost identical. 

So here's a couple of Meristella atoka from there:

  

The second specimen:

[Tidgy's Dad]

This is Orthostrophia strophomenoides parva from the Bois d'Arc Formation. I also have this species from the Haragan Formation which you can see posted earlier on this page. 

The specimen is 2.2 mm across at its widest point. 

Some nasty gloop, but one can see where the ribs bifurcate: 

Edited September 5, 2022 by Tidgy's Dad

[Tidgy's Dad]

The final specimen that I have from the Bois d'Arc Formaion of Oklahoma is this gorgeous Levenea subacrinata pumilis.

So thanks again to Ralph @Nimravis for his beauty and all the other Bois d'Arc and Harrigan Formation fossil posted above. 

 

 

[Tidgy's Dad]

This next collection of brachiopods and epibionts came in one of the amazing parcels I received from the marvelous @Herb.

They are all from the Birdsong Member of the Ross Formation of Parsons, Tennessee and are also Lochkovian in age, roughly the same time as the Haragan and Bois d'Arc Formations of Oklahoma and the New Scotland Shale of New York and a great number of the brachiopod species are common throughout all these beds. The Kalkberg of New York is very slightly younger and so has some of the same species, some of the same genera but different species and some types not found in the other formations and vice versa. 

It's amazing to know this huge ocean with many of the same species extended half way across what is now the USA from East to West and South to North. Wonderful. 

 

These first couple are Discomyorthis oblata. Or not. 

This species has a rather confusing taxonomic history, starting out as Orthis oblata Hall, 1857, but in 1862 Hall and Clarke erected the genus Rhipidomella and placed the species there, so it was Rhipidomella oblata. Schuchert then placed it in his new family Rhipidomellidae and subfamily Rhipidomellinae in 1913. All well and good. But it was then decided that Rhipidomella first appears in the Middle Devonian (Eifelian) so it became  Rhipidomelloides oblata according to Amsden 1958. But this genus was a synonym of Dalejina which had precedence as it had been created by Havlicek in 1953. So, confusingly, it is often referred to as genus Dalejina, species Rhipidomelloides oblata, which may be the correct designation, but is also called Dalejina oblata sometimes. When Johnson created the genus Discomyorthis in 1970 it was suggested that the species was placed therein creating Discomyorthis oblata which seems to be the most commonly used form today, though the genus is now restricted to the Pragian, so who knows? 

 

Many of the lumps on the shells are epibionts. Both are pedicle valves.

The beautiful flabellate muscle attachment scars separated by a short in front of the adductor scar. Not a great photo, but a clearer one will be shown later. 

The other specimen shows the shell interior better. 

The second specimen :

 

 

Edited September 10, 2022 by Tidgy's Dad

[Tidgy's Dad]

This encrusting bryozoan is on the anterior margin of the first of the Discomyothis oblata specimens shown in the post above. 

Due to the size and round to oval nature of the well spaced zooecia and the multitude of tiny mesopores, I think this is the cystoporate  Fistulipora sp. common in the Birdsong Formation of Tennessee. Four species are present. 

 

Edited September 12, 2022 by Tidgy's Dad

[Tidgy's Dad]

This interesting epibiont on a Discomyorthis oblata pedicle valve would seem to be what is described as the bryozoan Ptylodictya tenuis. 

It appears to be the holdfast / base of a ramose bryozoan colony. 

Hmmm. 

Ptylodictya seems to have been replaced by Ptilodictya well over a hundred years ago and no listing for the species or the genus Ptylodictya occurs in Bryozoa.net, Mindat or Fossilworks. There are only a few mentions of it at all. that I can find on the web.  Looks more like a crinoid holdfast to me, in the specimens I've seen sometimes standing alone and other times surrounded by a bryozoan colony. But who am I to disagree? 

[Tidgy's Dad]

I think the following encrusters on both Discomyorthis oblata specimens are microconchids. 

Most of the literature still has them listed as Spirorbis laxus, but it is now clear that Spirorbis doesn't appear until the Miocene, and the serpulids bot until the end of the Permian, only becoming common as fossils in the Late Jurassic. All spiral forms before then are microconchids, part of the class Tentaculita, so not 'worms' at all. 

No one has reclassified the Lochkovian microconchids of the USA yet (someone needs to sort out several species in these formations, not just the Birdsong), but it is likely this will prove to be Palaeoconchus and thus possibly will end up as Palaeoconchus laxus. 

Actually, these following specimens might have ribs which would mean they are more likely Microconchus sp. Maybe two types present? 

 

Edited September 13, 2022 by Tidgy's Dad

[FossilNerd]

I love epibionts!  

 

 

On 9/10/2022 at 5:54 PM, Tidgy's Dad said:

The beautiful flabellate muscle attachment scars separated by a short in front of the adductor scar.

Is it weird that I like looking at muscles scars on many brachiopod valves more so than plications? These are just gorgeous! 

[Tidgy's Dad]

On 9/15/2022 at 9:59 PM, FossilNerd said:

These are just gorgeous! 

Thank you, Wayne. 

Yes, internal details such as muscle scarring, articulation processes and pseudopuctate bumps can be very beautiful and interesting. And, of course, often diagnostic or of at least some help in identifying the specimens. 

 

For rhynchonellids, though, you usually have to do rib counts and look at size and shape to determine the id, as only very rarely are the interior details visible on a fossil. 

This is true for the rhynchonellids found in the Birdsong Shale of Tennessee. 

The following specimen came to me labelled as Sphaerirhynchia lindensis, but as mentioned in my post regarding this species from the Haragan Formation of Oklahoma earlier on this page, this specimen is quite different, particularly regarding the shape of the tongue and the number of costae on the fold, sulcus and flanks. 

It is interesting to note that the Middle to late Ordovician brachiopods in my collection are almost entirely from the family Rhynchotrematoidea, then in the Silurian there is a mix of that superfamily and members on the Uncinuloidea but in the Early Devonian most specimens seem to belong to this latter clade. (there are still some others present, but less common). All from different families, in the Birdsong we find Sphaerirhynchia, Eatonia and Uncinulus. 

 

Uncinulus is named for the Latin word for 'staple'   .

And is quite suitable to describe the tongue of this genus. 

Three species seem to occur in the Birdsong Shale member of the Ross Formation, U.

vellicatus, which is about 2 cm or more across, U. mutabilis, teardrop shaped with a pointed beak and U. swaynensis, quite small and very 'squared-off'. 

I think my one is a lovely specimen of Uncinulus swaynensis.' 

   

[Tidgy's Dad]

Atrypa 'reticularis' from the Birdsong Shale of Parsons, Tennessee. 

This species sensu stricta is now limited to the Silurian of Gotland, Sweden, (Copper 2004), but is still seen all over the shop, as nobody has reclassified most of them. 

The genus Atrypa is still correct for the Ross Formation and Birdsong Shale Member, but, for now, it should be listed as Atrypa sp. 

[Tidgy's Dad]

And the beautiful athyrid, Rhynchospirina globosa, also from the Birdsong of Parsons, Tennessee. 

Rhynchospirina formosa also occurs in the Birdsong Shale, but is much smaller, broad rather than elongate, has fewer costae and doesn't have the prominent overhang of the beak of the pedicle valve over the brachial valve. 

Both species also occur in the Heidelberg Group of New York.