Like many other Moroccan trilobites, this is named after a European trilobite. This may be a different species from the European S. buchii or it may be that something in the water made the Moroccan S. buchii get extra large. This Moroccan Selenopeltis is so far as I know the largest species within the order Ondontopleurida. Note the family resemblance to the tiny Meadowtownella trentonensis.

This is one of the most faked of trilobites. Many large "Moroccan Selenopeltis trilobites" are sold on ebay, few if any of them are real. This one is real, the shell isn't perfect but it's there.