Greenops

Greenops is a mid-sized Devonian trilobite of the order Phacopida, subfamily Asteropyginae.
They are mainly reported from the mid-Devonian Hamilton Group of upstate New York and southwestern Ontario. A similar-looking trilobite from Morocco is often mis-labelled "Greenops". "Greenops" had schizocroidal eyes (resembling compound eyes in insects), large genal spines and short, sharp spines at the tip of each segment of the pygidium ("tail"). "Greenops" lived in warm, fairly deep water. In the Hamilton Group of New York, they are found with "Phacops", "Dipleura" and "Bellacartwrightia", a trilobite that resembles "Greenops" but has much larger pygidial spines. In Ontario, they are found in the Widder Formation, which outcrops at Arkona, where they are, by far, the dominant trilobite.
"Greenops"' average size is about . They were fairly common trilobites, and are easily identified. While it is rare to find a complete disarticulated body, segments and tails are fairly common. They are fairly common finds in Late Devonian limestones, especially storm deposits. They are identified by their tails, which sport several spines. They were medium to small sized trilobites, which were most likely preyed upon by ammonoids, straight cephalopods, sharks, and small placoderms, hence the defensive spines. All of these animals have been found in close association with this trilobite. "Greenops" can also be found in deep marine deposits, but there it is fairly rare. "Greenops" was a small, yet charmingly beautiful trilobite, like its close companion "Phacops".
Taxonomy.
Species previously assigned to "Greenops".
Some species originally described under this genus have since been reassigned to other genera.
Distribution.
Fossils of "Greenops" have been found in France, the Floresta Formation of the Altiplano Cundiboyacense, Colombia, Libya, Spain, United States (Illinois, Indiana, Iowa, New York, Pennsylvania), Canada (Arkona, Ontario) and the Caño del Oeste Formation of Venezuela.