Characteristics of Chordates and Their Groups

These flashcards cover the key vocabulary related to the distinguishing characteristics of chordates and their various groups.

Chordata

A phylum characterized by having a dorsal nerve cord, a dorsal notochord, pharyngeal slits, and a postanal tail.

Somites

Segments of mesoderm that develop into body structures in chordates.

Dorsal nerve cord

A hollow tube lying along the dorsal side of chordates that develops into the central nervous system.

Notochord

A flexible rod that provides support and is present in the embryonic stage of chordates.

Amphibians

A class of animals that typically have legs, lungs, and undergo metamorphosis, including frogs and salamanders.

Vertebral column

A series of vertebrae extending from the head to the tail in vertebrates, providing structural support.

Watertight amniotic eggs

Eggs that have protective membranes and fluids for development, characteristic of reptiles and birds.

Endothermy

The ability of an organism to regulate its body temperature through internal means, found in mammals.

Prototheria

A group of monotremes, such as the platypus, laying eggs instead of giving live birth.

Theria

A clade consisting of marsupials and placental mammals that give live birth.

Urochordata

A subphylum of chordates that includes tunicates.

Cephalochordata

A subphylum of chordates that includes lancelets.

Agnatha

A superclass of jawless fish, including lampreys and hagfish.

Chondrichthyes

A class of fish characterized by a cartilaginous skeleton, including sharks and rays.

Osteichthyes

A class of fish with a bony skeleton, including both Actinopterygii and Sarcopterygii.

Anura

An order of amphibians that includes frogs and toads.

Caudata

An order of amphibians that includes salamanders.

Apoda

An order of amphibians that includes caecilians.

Chelonia

An order of reptiles that includes turtles.

Rhynchocephalia

An order of reptiles represented by the tuatara.

Squamata

An order of reptiles that includes lizards and snakes.

Crocodylia

An order of reptiles that includes crocodiles and alligators.

Mammary glands

Glands in female mammals that produce milk to nourish young.

Specialized teeth

Teeth adapted for specific diets, such as herbivory or carnivory, seen in some mammals.