Chordates

Chordata

A phylum of deuterostome coelomates, whose nearest relatives are echinoderms.

Deuterostome

An animal whose mouth develops from the second opening in the embryo, a characteristic of chordates and echinoderms.

Coelomate

An animal with a true coelom, a fluid-filled body cavity entirely surrounded by mesoderm.

Nerve cord

A hollow structure that runs along the back of chordates, part of the central nervous system.

Notochord

A flexible rod made of cartilage that supports the body of a chordate during its development.

Pharyngeal slits

Openings in the pharynx that appear during the development of all chordates, used for filter-feeding in some species.

Postanal tail

An extension of the body past the anal opening, characteristic of all chordates at some stage of development.

Urochordata

A subphylum of Chordata that includes tunicates, which are marine animals.

Cephalochordata

A subphylum of Chordata that includes lancelets, which are small, fish-like marine animals.

Vertebrata

A subphylum of Chordata that includes animals with a backbone, such as fishes, amphibians, reptiles, birds, and mammals.

Tunicates

Marine animals in the Urochordata subphylum, characterized by a larval stage that is tadpole-like.

Sessile filter-feeders

Organisms that remain attached to a substrate and filter small particles from the water for food.