zoo-, zoa-, zo-, -zoic, -zoid, -zoite, -zoal, -zonal, -zooid, -zoon, -zoa, -zoan +

1. A geologic era extending from the end of the Precambrian to the beginning of the Mesozoic, dating from about 600 to 230 million years ago.
2. The rock strata formed during this era.

1. The study of fossil animals and their evolution.
2. Animal life of the geological past.
3. Prehistoric animals.

A pandemic (wide-spread, universal) disease of animals.

A rarely used taxon of the animal kingdom at one time erected to contain the phylum Porifera, in distinction from the Eumetazoa containing all other metazoan animals.

Any of the sponges.

An animal, or animals, feeding on disintegrating or dead tissue.

The present eon of geologic time, beginning 570 million years ago, that consists of the Paleozoic, Mesozoic, and Cenozoic eras which marked by an abundance of fossil evidence of life, especially higher forms, in the corresponding rocks.

An exoerythrocytic tissue stage of malaria infection other than the primary exoerythrocytic stages (cryptozoite and metacryptozoite generations); consists chiefly of reinfection of the liver by merozoites produced by a blood infection (not found in falciparum [tropical parasitic disease] malaria).

1. A zooid that attaches itself to the back of its parent, at the same time carrying and nourishing another type called the gonozooid which subsequently breaks free to reproduce sexually.
2. The nonsexual phase or generation of an organism is which an alternation of generations or sequence of reproductive modes is involved.

Free-swimming larva of certain crustaceans including the spiny lobster and sea-crayfish.

A reference to minute water animals that form branching, mosslike colonies, and reproduce by budding.

A description of tapeworms in which the body is typically divided into proglottids; as opposed to monozoic forms.

The older Paleozoic faunal epoch, the age of primitive invertebrates.

The subkingdom which comprises all unicellular animals (by some regarded as non-cellular).

Included in the group are some which may also be classified as plants, the distinction being that these possess chlorophyll.

The killing of protozoans.