They are mainly reported from the mid-Devonian Hamilton Group of upstate New York and southwestern Ontario.

In the Hamilton Group of New York, they are found with Eldredgeops, Dipleura and Bellacartwrightia, a trilobite that resembles Greenops but has much larger pygidial spines.

While it is rare to find a complete disarticulated body, segments and tails are fairly common.

Greenops was a small, yet charmingly beautiful trilobite, like its close companion Eldredgeops.

[1] Fossils of Greenops have been found in France, the Floresta Formation of the Altiplano Cundiboyacense, Colombia,[2] Libya, Spain, United States (Illinois, Indiana, Iowa, New York, Pennsylvania), Canada (Arkona, Ontario) and the Caño del Oeste Formation of Venezuela.