Dear Guys,
Several years ago I found this piece of fin spine that is 3.5 mm width and by me it looks more similar to primitive shark like Onchus problematic fossils.
Here is visible vertical groove texture and also oblique area of little oblong tubercles.
The fossil is found in Late Silurian limestone erratic, the location was Varena town, South Lithuania.
Please help me to know, is it more like acanthodian or Onchus chondrichthyan?
Best Regards
Domas