Carboniferous- Permian fishes for ID

[D.N.FossilmanLithuania 458]

Good morning everyone!

I have collected many vertebrate fossils from Tournaisien dolomites, Carboniferous marls and Early Carboniferous- Permian carbonated sandstones.

I tried to identify the age of the erratics for a very long time and I think that all three types of erratics are from Carboniferous or Permian periods. 

There are many rhizodonts, megalichthyids, lungfish dental plates, one ganoid scale, small shark tooth and even one big ptyctodontid placoderm tooth 

(I have doubt if it is more famennian like or could be Tournaisien). In the same Tournaisien dolomites I have found many crinoids, brachiopods and molluscs.

From brachiopods the Productids, spiriferids, rhynchonellids are very numerous, there are also some athyridids and Orthotetes specimens. 

In the marls the clam shrimp remains are often, plant (like horsetail) remains are very rare, the majority of fishes are rhizodonts and there is also one specimen

of two skull bones from small amphibian. Please help to confirm vertebrate fragments (especially Sagenodus lower jaw and Ctenodus upper jaw plates), for the age

confirmation I also will show invertebrates if it is needed.

 

Best Regards

Domas

      

[D.N.FossilmanLithuania 458]

Here are three onychodont teeth and one ptyctodont tooth:

Productid brachiopods:

[D.N.FossilmanLithuania 458]

Rhynchonellid brachiopods:

 

The last two rhynchonellids and Orthotetes.

[D.N.FossilmanLithuania 458]

Spiriferid brachiopods. 

Athyririd brachiopods.

[D.N.FossilmanLithuania 458]

Bivalve fossils. 

And the last- some crinoids.

[D.N.FossilmanLithuania 458]

Any ideas, is the age determination and fossil identifications correct?

Regards

Domas

[D.N.FossilmanLithuania 458]

I am sorry that I forgot to mentioned the first vertebrate names as I think. 

1. I think, it is rhizodont gnathal plate. Length is 1,5 cm.

 

2. Megalichthys (?) scale, the length is 5 mm.

3. Small rhizodont scale, 2 mm diameter. 

[D.N.FossilmanLithuania 458]

4. Megalichthyid (?) head bone, 4 mm diameter.

5. Megalichthyid scale, 4 mm length. 

6. Small lepospondyl skull plates, the are 2 mm diameter. 

[D.N.FossilmanLithuania 458]

7. Lugfish dental plate, 3mm length. 

8. Lungfish dental plate, 3 mm length. 

[D.N.FossilmanLithuania 458]

9. a- Ctenodus, b- Sagenodus dental plates.  The both are 5 mm length.  

 

10. Ganoid scale of Moythomasia, 3 mm length.  

11. Insect leg segment (?), 2 mm length.  

[D.N.FossilmanLithuania 458]

12. Unidentified, probably rhizodont, bone. 13 mm length.  

[westcoast 391]

Nice variety of fossils. I really like the skull plates. I probably would have missed those.. I can't help but it seems like you already have good ID's

[D.N.FossilmanLithuania 458]

Dear Guys, 

I show to you the link in Ctenodus lugfish toothplate, please confirm if you could.

http://tetrapods.org/public-outreach/publications/Lungfish-toothplates-paper-2015.html

Best Regards

Domas 

 

And my fossil picture, too :

[jdp 693]

These might be scientifically important. I'm not seeing Sagenodus, but some of the lungfish tooth plates are intriguing.

 

What makes you think this is Tournasian? Which formation is this?

 

I'd be happy to discuss this in more detail in a direct message.

[D.N.FossilmanLithuania 458]

Dear jdp, 

 

Thank you for inviting to discuss, of course I can tell my arguments why I think it is beginning of Carboniferous:

1. Brachiopod fauna. Orthotetes is well known in Carboniferous, Composita- Late Devonian/ Carboniferous, from rhynchonellids the genus Leiorhynchus I identified 

is even found in Pennsylvanian, spiriferids in Early Carboniferous were quite similar to Late Devonian and my specimens are Spirifer like, sometimes quite big.

Productids are very specific.. I have found here Productella (thrived in Late Devonian- Mississippian), Strophalosia (In majority it is Carboniferous- Permian age), Neochonetes (Carboniferous- Permian) 

and some very strange Productus like brachiopod remains that look quite primitive, not very similar to late Productids.

2. Of course, lungfishes. Ctenodus is known only in Carboniferous, Sagenodus in Pennsylvanian- Early Triassic. Talking about Sagenodus I have to mention as the best version the lower jaw toothplate, although there are usually little more lines of pseudo teeth in that genus:

http://www.ctoz.nl/cgi/t/text/text-idx?c=ctz;sid=120b00083747e424be5463d71e8a3dc9;idno=m6701a02;view=text;rgn=div2;cc=ctz;node=m6701a02%3A9.1

(Fig. 44, a, lower toothplate called as Sagenodus serratus). I may be wrong, it also could be some other sagenodontid or even Gnathorhiza but the Gnathoriza pseudo teeth in toothplate are more protuberant and sharper:

https://www.fossilera.com/fossils/pennsylvanian-lungfish-gnathorhiza-mouthplate-texas

The other lungfishes in these quite melting dolomites do not look like simple dipterids that thrived in Devonian- Some pseudo teeth look like in rare and new species of Tournaisien lungfishes of British Isles. So, there are some similarities in Lungfishes between Devonian and Carboniferous but we have to know that the majority of species have been changed in that boundary.

3. Crinoids also. The stems are quite thin but they look Taxocrinid and tiny dendrocrinid like. 

4. Bivalves. In the upper picture bivalve looks similar to Bakewellid, the lower Edmondia is found in Mazon Creek of Pennsylvanian:

5. The differences between similar rock types. In all Lithuanian territory harder dolomites (not so melting) are used by rubble in roads and they are dark grey and very hard (Frasnian) and greenish grey and quite hard (from Zagare quarry, Northern Lithuania, Late Famennian). But my rocks with specific Brachiopods, vertebrates and other fossils are quite melting, sometimes even soft, little clayey or carbonated and sometimes there also can be found limestones with the same brachiopod genera as in another melting rocks. Talking about lungfish differences, I found Dipterus and Conchodus in the rubble of Zagare quarry but not in these rocks I showed!

6. Situation in Lithuania and Latvia. The Tournaisien rock layers are known in the Northwestern Lithuania and Southwestern Latvia, they are soft and in majority consist of sandstones, but there are also known marls, dolomites and in one literature I saw that even limestones... So, it could be little possible their origin from our region, but there is another point- in Carboniferous there are found only fishes and algae.

7. Prequarternary surface in neigboring regions. Tournaisien is known in Belgium and British Isles, Lithuania as we know belong to Baltic States in Eastern Europe. But in the northeast, there are also something interesting... A big row of Carboniferous- Permian prequarternary surface around Ural, Novaya Zemlya and near Archangelsk (the White Sea region). 

So, there are very many possibilities of Carboniferous in Lithuanian erratics although it is still not identified and local scientist have big doubts about it.

 

Best Regards

Domas   

 

    

    

[jdp 693]

As far as age is concerned, if this is Fammenian or Tournaisian, that would need to be confirmed with conodont ages. The inverts you list are pretty long-ranging and you would need species-level identifications to pin down an exact age, and even then it would be difficult. 

 

I am not certain about some of the fish and ?tetrapod IDs. I think the pair of bones you ID as lepospondyl likely are not. I am not seeing anything particularly tetrapod-y about those, but they're tiny and there's very little there to indicate anything in particular about what sort of animal they came from. This is something that would require further study by a professional. I think the element identified as ptyctodont is likely some sort of holocephalan tooth plate, and I'm unsure of some of the megalichthyid, rhizodont, and onychodont IDs. If there is an onychodont and a ptyctodont, that would argue unequivocally for a Devonian age, but there may be other possible IDs.

 

As for the lungfishes themselves, the many-rowed toothplate is vaguely Ctenodus-like, Ctenodus is a complex of many species (some possibly not related closely to each other) that spans from the latest Devonian to the lower Permian. As with the marine invertebrates, the exact species would be required to say anything about the age of the rocks, and this toothplate may in fact be a new species. It is quite small as a representative of the genus. The toothplate IDed as Sagenodus definitely does not belong to that genus. It is also definitely not Gnathorhiza (and incidentally, the toothplate you linked to which is IDed as Gnathorhiza is actually Sagenodus. Gnathorhiza have a reduced number of extremely blade-like ridges). Although it looks vaguely post-Devonian, it isn't convincingly so. It looks vaguely like some toothplates from the Fammenian of North America referred to Dipterus (but which probably do not belong to that genus). It also looks vaguely like toothplates of Rhinodipterus. Again, though, I would need a closer look.

 

You said this material comes from glacial erratics?

 

 

[D.N.FossilmanLithuania 458]

Dear jdp, 

 

Of course this material is from glacial erratics, I collected them in Varena town, South Lithuania.

But I also would like to tell something about onychodonts and ptyctodonts- they both dissappeared in Late Carboniferous as it is visible in fossilworks.org  

I think Late Famennian ptyctodont can be also very similar to Early Mississippian survived specie- we have to know that Devonian extinction did not happen in Late Famennian 

but bit happened in Late Frasnian. Only some species were not adapted to survive in the beginning of Carboniferous.

Of course, the species would be very helpful and I am very intrigued about the possible new species of Ctenodus you mentioned!

 

Best Regards

Domas

[jdp 693]

Onychodonts and ptyctodonts are both limited to the Devonian. The only sarcopt lineages which survive the end-Devonian extinction were tetrapods, rhizodonts, megalichthyids, coelacanths, and lungfishes. To our currentl knowledge, archaic forms like onychodonts and porolepiforms definitely went extinct at or before the boundary. At one time people thought there might be placoderms in the Tournaisian, but that was due to uncertainty of where the Fammenian-Tournaisian boundary might be. Now that we've got a better handle on true Tournaisian localities and a better sense of where the boundary is, we're not seeing quite the same level of mixing for these archaic lineages.

 

I'll note that the Fossilworks/PBDB database is good as an aggregate resource for paleoecological analysis, but many of the individual records are actually incorrect or out of date. My experience working with these databases (as a professional) is that specific occurrences do need to be carefully validated. I would not trust those ages without validating them directly and ensuring that the IDs and locality ages represent the current state of knowledge.

[D.N.FossilmanLithuania 458]

Dear jdp, 

Thank you very much for the note, that means only the some part of my erratics are Tournaisian. So, we could say the dolomites, limestones and sandstones belong to Devonian- Carboniferous boundary.  Today I made the pictures of Ctenodus tooth plate and "possible sagenodontid" from different sides, maybe these pics will be helpful.

 

Best Regards, Domas 

[jdp 693]

Hi Domas,

 

Yes, the first toothplate is very Ctenodus-like. There are a range of genera with specifically Ctenodus-like teeth, and this could potentially be Ctenodus sensu stricto or it could be one of those similar taxa. That unfortunately does not narrow down the age much.

 

I've given that second toothplate a lot of thought but I'm still not sure I've got an ID for you. It looks vaguely like a prearticular toothplate from something in the Orlovichthys part of the tree but I've never really seen this specific tooth morphology before. I'll give it a bit more thought and check out a few references from the Russian literature and get back to you. I am convinced it's not Sagenodus though.

[D.N.FossilmanLithuania 458]

Dear jdp,

thank you very much for the comment and possible Orlovichthys identification!

What do you think about these two tooth plates below?

Maybe they are dentary or something similar? 

 

Best Regards

Domas