Here is a nearly compleate Dalmanitina socialis that shows some nice details. This trilobite shows for example also the single lenses of the Phacopid eye.
Location:
Beroun, Barrandian area, Czech Republic
Size trilobite:
about 70 mm long
Age:
Middle Ordovician, Llandeilo, Letná Formation (About 464 mill. Years old)