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Of or pertaining to rocks or strata older than the Paleozoic, in many of which the eozoön has been found.

Like or belonging to the earliest forms of animal life.

Pertaining to, or including, similar forms or kinds of life; as, homoeozoic belts on the earth's surface. E. Forbes.

More recent than the Paleozoic, -- that is, including the Mesozoic and Cenozoic.

Of or pertaining to, or designating, the older division of geological time during which life is known to have existed, including the Silurian, Devonian, and Carboniferous ages, and also to the life or rocks of those ages. See Chart of Geology.

The Paleozoic time or strata.

Having tissued composed of cells.

A native of Acadie. Acadian epoch (Geol.), an epoch at the beginning of the American paleozoic time, and including the oldest American rocks known to be fossiliferous. See Geology. -- Acadian owl (Zoöl.), a small North American owl (Nyctule Acadica); the saw-whet.

nited States Geological Survey and some other authorities, between the Archæan and the Paleozoic, from both of which it is generally separated in the record by unconformities. Algonkian rocks are both sedimentary and igneous. Although fossils are rare, life certainly existed in this period. -- n.

the Lower Silurian. It includes an Azoic age, previous to the appearance of life, and an Eozoic age, including the earliest forms of life.

Azoic age (Geol.), the age preceding the existence of animal life, or anterior to the paleozoic tome. Azoic is also used as a noun, age being understood. See Archæan, and Eozoic.

genus of fossil univalve shells, believed to belong to the Heteropoda, peculiar to the Paleozoic age.

One of the divisions of Crinoidea found fossil in paleozoic rocks; pentremites. They are so named on account of their budlike form.

d families belonging to the group Rugosa; -- also called cup corals. Thay are found in paleozoic rocks.

An order of Crinoidea, mostly fossils of the Paleozoic rocks. They were usually roundish or egg-shaped, and often unsymmetrical; some were sessile, others had short stems.

rder of Merostomata, of which the genus Eurypterus is the type. They are found only in Paleozoic rocks. [Written also Eurypterida.]

Belonging, or relating, to the secondary or reptilian age, or the era between the Paleozoic and Cenozoic. See Chart of Geology.

the latest period of the Silurian age. Oriskany period, a subdivision of the American Paleozoic system intermediate or translational in character between the Silurian and Devonian ages. See Chart of Geology.

An extinct genus of Brachiopoda, abundant in the Paleozoic rocks.

An extinct genus of Paleozoic Cephalopoda, having a long, straight, conical shell. The interior is divided into numerous chambers by transverse septa.