animal clades

Phylum Porifera

A group of sedentary animals known as sponges, characterized by a lack of true tissues and organs.

Sedentary animal

An organism that does not move significantly from one place to another.

Suspension feeders

Organisms that obtain food by filtering suspended matter and food particles from water.

Phylum Cnidaria

A clade that includes animals with true tissues and specialized cells, such as jellyfish, corals, and hydras.

Gastrovascular cavity

The central digestive compartment found in some animals, including cnidarians.

Diploblastic

Organisms that develop from two germ layers: endoderm and ectoderm.

Radial symmetry

A body plan in which body parts are arranged around a central axis.

Anthozoa

A class within Cnidaria that includes organisms like corals and sea anemones that exist primarily as polyps.

Medusozoa

A class within Cnidaria that includes jellies and other forms that have a medusa stage in their life cycle.

Bilateral symmetry

A body plan in which the left and right sides of the body are mirror images.

Phylum Platyhelminthes

A group of flatworms that are acoelomates and characterized by their flat body shape.

Acoelomates

Animals that lack a coelom, or body cavity.

Phylum Mollusca

A diverse group of soft-bodied animals, often protected by a hard shell.

Visceral mass

The part of a mollusk that contains most of its internal organs.

Phylum Annelida

A group of segmented worms characterized by bodies composed of fused rings.

Coelomates

Animals that possess a coelom, a fluid-filled body cavity.

Phylum Arthropoda

The largest phylum of animals, characterized by segmented bodies and jointed appendages.

Tagmosis

The evolutionary process of merging segments into specialized regions of the body.

Chondrichthyes

A class of jawed vertebrates including sharks, rays, and skates with cartilaginous skeletons.

Echinodermata

A phylum of marine animals characterized by radial symmetry in adults and a water vascular system.

Notochord

A flexible rod made of notochord cells that provides skeletal support in chordates.

Tetrapods

Vertebrates that evolved from lobe-finned fish and adapted to land.

Amniotic egg

An egg with membranes that protect the embryo, allowing for reproduction in dry environments.

Mammal

A class of animals characterized by mammary glands, hair, and complex brain structures.

Monotremes

Egg-laying mammals, such as the platypus.

Marsupials

Mammals whose embryos develop in a pouch after being born at an early stage.

Eutherians

Mammals characterized by long gestation periods, completing development in the uterus.