Bargain "Devil Horned" Cyphaspis Walteri Trilobite Cluster

This is a cluster of four Cyphaspis walteri trilobites collected from the Bou Dib Formation near Mrakib, Morocco.
This species is sometimes referred to as the "Devil Horn" Cyphaspis for obvious reasons. Three of the specimens are dorsal and one is preserved ventrally. The largest one measures about 1 1/2" long including its spines. The spines and horns have been left partially embedded in the limestone and not prepared free-standing.

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)