Phacops is a genus of trilobite

Trilobite

Trilobites are a well-known fossil group of extinct marine arthropods that form the class Trilobita. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period , and they flourished throughout the lower Paleozoic era before...

 in the order Phacopida

Phacopida

Phacopida is an order of trilobite that lived from the Ordovician to the Devonian. It is made up of a morphologically diverse group of related suborders....

, family Phacopidae

Phacopidae

Phacopidae is a family of trilobites of the order Phacopida, including the following genera:*Acernaspis*Acuticryphops*Adastocephalum*Afrops*Ainasuella*Altaesajania*Ananaspis*Angulophacops*Arduennops...

 that lived in Europe and North American in the Silurian

Silurian

The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...

 and Devonian

Devonian

The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...

 periods. It was a rounded animal, with a globosa head and large eyes, and probably fed on detritus

Detritus

Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...

. Phacops, also commonly known by the synonym Eldredgeops, is often found enrolled, a biological defense mechanism widespread among smaller trilobites but nearly perfected by this genus.