Eldredgeia is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 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...

s 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....

, suborder Phacopina

Phacopina

Phacopina is a suborder including many trilobites.-External links:* - various photos, some of Phacopina...

, family Calmoniidae

Calmoniidae

Calmoniidae is a family of trilobites from the order Phacopida, suborder Phacopina, superfamily Acastoidea.It contains the following genera:*Anchiopella*Andinacaste*Australocaste*Australops*Awaria*Bainella*Belenops...

. This genus comes from the 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...

 of South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

, usually found in nodules. The trilobite Eldredgeia venustus, from Bolivia

Bolivia

Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

, is the most common South American trilobite on today's fossil market, and even then it is not all that common. This genus has a spiny pygidium

Pygidium

The pygidium is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. It contains the anus and, in females, the ovipositor...

and usually the eye facets are well preserved.

Species

• Eldredgeia venustus from the Pimenteira Formation
• Eldredgeia cf. E. venustus from South Africa
• Eldredgeia paituna Hartt and Rathbun, 1875 from Erere Sandstone, Para, Brazil.