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

The second of the earth's three major geologic eras of Phanerozoic time and the interval during which the continental landmasses as known today were separated from the supercontinents Laurasia (North America and Eurasia) and Gondwana by continental drift.

It occurred before the Cenozoic and after the Palaeozoic periods and was marked by the development of the ancestors of the major plant and animal groups that exist today and the extinction of the dinosaur, suddenly at the end of the Cretaceous period.

It lasted from about 245 to 66.4 million years ago and included, in order, the Triassic Period, the Jurassic Period, and the Cretaceous Period.

The Mesozoic is divided into three time periods: the Triassic (245-208 Million Years Ago), the Jurassic (208-146 Million Years Ago), and the Cretaceous (146-65 Million Years Ago).

Mesozoic means "middle animals", and is the time during which the world fauna changed drastically from that which had been seen in the Paleozoic.

Dinosaurs, which are perhaps the most popular organisms of the Mesozoic, evolved in the Triassic, but were not very diverse until the Jurassic.

Except for birds, dinosaurs became extinct at the end of the Cretaceous period. Some of the last dinosaurs to have lived are found in the late Cretaceous deposits of Montana in the United States.

The Mesozoic was also a time of great change with terrestrial vegetation. The early Mesozoic was dominated by ferns, cycads, ginkgophytes, bennettitaleans, and other unusual plants.

Modern gymnosperms; such as, conifers, first appeared in their current recognizable forms in the early Triassic. By the middle of the Cretaceous period, the earliest angiosperms had appeared and began to diversify, largely taking over from the other plant groups.

Animals are a major group of organisms, classified as the kingdom Animalia or Metazoa.

In general they are multicellular, capable of locomotion and responsive to their environment, and feed by consuming other organisms.

A multicellular animal.

A microscopic animal.

In biology, pollinated by small animals.

A term used to distinguish those tapeworms the body of which is not divided into proglottids (one of the segments of a tapeworm, containing both male and female reproductive organs).

An order of rhizopod protozoans that includes the slime molds when they are regarded as animals.

Slime molds are peculiar protists that normally take the form of amoebae, but under certain conditions develop fruiting bodies that release spores, superficially similar to the sporangia of fungi.

They should not be confused with true molds, which are actually fungi. Although cosmopolitan in distribution, they are usually small and rarely noticed. There are several different groups.

1. A dwarf zooid (an individual forming part of a colony; a polyp).
2. A bryozoan heterozooid that has only one tentacle. Bryozoan are members of the phylum Bryozoa: the moss animals, a phylum of minute, mosslike marine and freshwater creatures, with distinct alimentary canals, that form permanent colonies and reproduce by budding.

Those animals that inhabit the middle depths of the sea; neither benthos (animals and plants living on the bottom of a sea or lake) nor plankton (animal and plant life, mostly microscopic, which generally floats and drifts near the surface of a lake, river, or sea).

A defensive zooid in a hydroid or siphohonophore, bearing many stinging cells.

Siphohonophore belong to the Siphonophora which is an order of marine hydrozoan coelentrates, both medusoid and polypoid individuals joining to form free-swimming colonies, often large and brightly colored, with highly toxic stings; this includes the Portuguese man-of-war.

The period of geological time from the end of the Mesozoic to the present.

1. Any individual developed from an egg.
2. A zooid or individual unit of a colonial organism, developing from an ovum, as distinct from a blatozooid which develops by budding.

The terms are used with reference to colonies of tunicates (e.g. sea-squirts) or similar organisms.

A geologic era exending from the end of the Precambrian to the beginning of the Mesozoic, dating from about 600 to 230 million years ago.

The study of the distribution of fossil animal remains.