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 has schizocroidal eyes (resembling compound eyes in insects), large genal spines and short, sharp spines at the tip of each segment of the pydgidium ("tail"). Greenops lived in warm, fairly deep water. In the Hamiltin 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 1 to 1.5 inches.Greenops are fairly common trilobites, and are very easily identified. While it is rare to find a complete Greenops disarticulated body segments and tails are fairly common. They are fairly common finds in late Devonian limestone, especially storm deposits. They are easily 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.

References

Ludvigsen, Rolf, Fossils of Ontario, Part 1: The Trilobites. Toronto: Royal Ontario Museum Press, 1983