Hello,
this is a fragment of a large acanthodian spine. Length about 16 cm, width up to 2,4 cm. All I know is that it's from the devonian of the Maider area in Marocco (scale = match = 45 mm).
Does anyone know more about that material from Marocco? (Genus, more precise data about the stratigraphic age?).
I think it's probably Machaeracanthus, but I'm not sure.
Thanks,
araucaria1959