Diacalymene

Diacalymene is a genus of trilobites from the order Phacopida, suborder Calymenina. This genus is large compared to most other Calymenina; 10 centimeter (4 in) long specimens are common.

Fossils are found in nodules, usually outstretched. They are from the Ordovician of Morocco and are heavily mined. These fossils may be one of the most common trilobites on the market today.