Trimerocephalus is a genus of trilobites from the order Phacopida, family Phacopidae. This genus is from the late Devonian and can be found in Morocco, Germany and occasionally in other European countries. These trilobites look similar to Ductina, but differ in that on the cephalon there are destinguishable remains of where eyes used to be, unlike in Dunctina where-as the eyes and any sign of the genus having eyes is not apparent. Some Known Species and Locations.