Animal Diversity

Multicellular

Groups of similar cells work together in groups called tissues.

Heterotroph

Animals digest food internally instead of producing their own basic organic molecules (plants) or digesting food externally (fungi).

Eukaryotes

Nucleus and membrane bound organelles in each cell.

Tissues

Undergo cell cleavage- cell division without growth- resulting in a blastula or ball of cells that develops tissues from germ layers.

Diploblastic

Animals with two germ layers: the ectoderm and endoderm.

Mesoderm

Animals with a mesoderm are called triploblastic. The mesoderm fills the space between the ectoderm and endoderm, giving rise to muscles and most organs.

Coelom

Cavities fully contained by the mesoderm

Hemocoel

A cavity between the mesoderm and endoderm

Cambrian Explosion

An event 535-525 M years ago that resulted in over half of animal phyla being created.

Metazoa

All animals

Eumetazoa

Animals with tissues (All except porifera)

Bilateria

All animals except cnidaria, ctenophora, or porifera. These have bilateral symmetry.

Deuterostomia

A clade of Bilateria that includes echnioderms and chordates. These have distinct early blastula development from others, including how cells divide, how coelom/mesoderm form, and how the digestive tube forms.

Lophotrochozoa

A group that includes tape worms, snails, and earth worms. United by genetic characteristics, though lophophore tentacles and trochophore larvae are found in some, but not all phyla.

Ecdysozoa

Contains Arthropods and Nematodes. They have an exoskeleton that can be shed via ecdysis.