Devonian
The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...
trilobite
Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most succ ...
of the order
Phacopida
Phacopida ("lens-face") is an order of trilobites that lived from the Late Cambrian to the Late Devonian. It is made up of a morphologically diverse assemblage of taxa in three related suborders.
Characteristics
Phacopida had 8 to 19 thoraci ...
, 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 ''
Eldredgeops
''Eldredgeops'' is a genus of trilobites in the order Phacopida, family Phacopidae, known from the late Middle and earliest Upper Devonian of Morocco and the USA.
Description
Like in all sighted Phacopina, the eyes of ''Eldredgeops'' are com ...
'', ''
Dipleura
''Dipleura'' is a genus of trilobites in the order Phacopida. It was described by Green in 1832, and the type species is ''Dipleura dekayi''. The type locality was in the Hamilton Group in New York.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
placoderm
Placoderms (from Ancient Greek πλάξ 'plax'', ''plakos'''Plate (animal anatomy), plate' and δέρμα 'derma'''skin') are vertebrate animals of the class (biology), class Placodermi, an extinct group of prehistoric fish known from Pal ...
s, 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 ''Eldredgeops''.
Fossils of ''Greenops'' have been found in France, the
Floresta Formation
The Floresta Formation (, Df) is a geological formation of the Altiplano Cundiboyacense in the Eastern Ranges of the Colombian Andes. The sequence of siltstones, shales, coquinas and sandstone beds dates to the Devonian period; Late Emsian, Eif ...
of the
Altiplano Cundiboyacense
The Altiplano Cundiboyacense () is a high plateau located in the Eastern Cordillera of the Colombian Andes covering parts of the departments of Cundinamarca and Boyacá. (Do not confuse with The Altiplano or the Altiplano Nariñense, both fur ...
, Colombia,Morzadec et al., 2015, p.348 Libya, Spain, United States (Illinois, Indiana, Iowa, New York, Pennsylvania), Canada (Arkona, Ontario) and the
Caño del Oeste Formation
Caño is a barrio in the municipality of Guánica, Puerto Rico. Its population in 2010 was 1,788.
See also
* List of communities in Puerto Rico
In the archipelago and island of Puerto Rico, there are 78 municipalities serving as second-level ...
Fossilworks
Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world.
History
Fossilworks was cr ...