Hello Matija;

The radiating ridges on the specimen reminds me of the osteoderms in the skin of crocodilians. Is the specimen thin or does it extend straight through the slab? If it goes straight through, that suggests that it is wood. What does the other side of the slab look like?

Best regards, Jim Des Lauriers

Hello Jim,

The specimen is just like on photos, it's oval shape, with just small elevation in center. It is imprint/impression so the thickness is problematic, but it was probable 4-5 mm (calculated on the basis of the depth of the specimen). Yes, this radiation ridges are visible, and it meke me think, that are plant-made, but still.

Hello Matija;

Well! if it is thin and plate-like as you describe, I like the osteoderm idea. Look for some images of crocodilian osteoderms and see what you think.

Cheers, Jim

Hi, Jim

thanks for your idea. All best, Matija

To me it looks like a thin bone of a labyrinthodontian or an osteoderm of a phytosaur

Acho que pode ser uma escama de peixe...

Thanks for help. I will check all options, thanks. All best, Matija

Obrigado pela ajuda ou assistência. Matija

The sediment is sandstone, probable from semi-marine environment (?). Thanks for help.

superficially it looks like a huge scale, but I would also say reptile osteoderm.

Looks a bit like dipnoan scale, for me.

Yes, this is good idea, I will look this too. Thanks, Dawid.

I agree with Dawid. On this photographs it looks like a cycloid scale, possibly dipnoan. However it might be labyrinthodontian or even reptilian. Searching for fish comparison look for work of A. Kemp (e. g. J. of Morph. 273:530–540), P. Skrzycki (in polish: Ewolucja, 4: 42-51) or my and A. Bodzioch (Pal. Res. 22, no. 1, pp. 91–100 -> I can send you some additional photograps privately if it would help).

Mateusz, thanks for you ideas. For any literature and photos, you could send me on my mail - [email protected]. Thanks again.