Scale remains from Lithuania: How to separate Kenichthyids from Osteolepids and Canowindrids from other tetrapodomorphs?

[D.N.FossilmanLithuania]

Dear Guys,

 

I would like to show you one part of my tetrapodomorph finds- scales of "Kenichthyidae" (the lower edges of dentin area are wave like and somewhere the growths in lower sides are visible), 

scales of Canowindridae (quite thin, not sharp-angled and have shorter internal rigde than osteolepids) and osteolepid scales (they have quite smooth, not wave likey edges of cenmtral dentin area and sometimes are much more oblong, the side around dentin area is usually narrow as I have seen).

The remains are collected in glacial erratics of Lithuania, the age of them is Pragian- Famennian. Although Kenichthys is found in China and Canowindrids are still known only in Australia, here are many scales in Devonian erratics that have almost the same features! Some canowindrid scales are very thin and have the canal system very similar to Marsdenichthys tetrapodomorph fish. 

Here are two links.

1. Kenichthys scale (F):

 https://www.researchgate.net/figure/Anteroventral-process-of-scales-A-C-Powichthys-spitsbergensis-sp-nov-Wood-Bay_fig11_213770139

2. Marsdenichthys scales (A-E):  

 https://www.researchgate.net/figure/Scales-of-tetrapodomorph-fishes-A-E-Scales-of-Marsdenichthys-longioccipitus-A_fig5_213771854

 

I have seen in  wikipedia that Marsdenichthys has been tried to assign to Rhizodopsids and Canowindrids but Rhizodopsids are known only from Mid Carboniferous so they could not live in Emsian and it is more likely that the genus is canowindrid relative.  Please tell your ideas- how to separate these three similar taxons of tetrapodomorphs by scales? Could my methods be correct?

 

Best Regards

Domas

 

1. Kenichthyidae remains (2- 6 mm length)

[D.N.FossilmanLithuania]

2. Canowindrid scales (3-6 mm length)

[D.N.FossilmanLithuania]

3. Typical osteolepidid scales (4- 6 mm length). And ther last question- Did osteolepids live from Eifelian or from Emsian? 

As I know the Middle Old Red sanstone begins in Emsian age but I am not sure if they appear from the lower stage boundary.

Any help will be appreciated!

 

Best Regards

Domas 

[Plax]

very interesting and nice pics. Hopefully there is some literature available on this specific topic. My apologies for commenting without any constructive comments.