Two, Large Devil Horned Cyphaspis Trilobites - One Ventral

This is a really cool piece, featuring a pair of devil-horned Cyphaspis (Cyphaspis walteri) trilobites. One is preserved dorsally while the other is ventral. There is also the head of a third specimen present on the rock.

This species was finally formally described in 2014. A link to the paper can be found below.

“Devil horned” Cyphaspis (Trilobita, Otarioninae): examples from the Middle
Devonian of the Ardennes (Belgium), Eifel (Germany) and Ma’der (Morocco)