The phylum whose members have a notochord, a nerve cord, and slits in their throat area at some point in their lives.
A flexible rod that supports a chordate's back.
The bones that make up the backbone of an animal.
An animal whose body does not produce much internal heat.
An animal whose body regulates its own temperature by controlling the internal heat it produces.
An ectothermic vertebrate that lives in the water and has fins.
A tissue that is more flexible than bone.
An internal gas-filled organ that helps a bony fish stabilize its body at different water depths.
An ectothermic vertebrate that spends its early life in water and its adult life on land.
The larval form of a frog or toad.
An organ found in air-breathing vertebrates that exchanges oxygen and carbon dioxide with the blood.
An upper chamber of the heart that receives blood.
A lower chamber of the heart that pumps blood out to the lungs and body.
The specific environment in which an animal lives.
An ectothermic vertebrate that lays eggs and has lungs and scaly skin.
An organ that filters wastes from the blood.
A watery fluid produced by the kidneys that contains wastes.
An egg with a shell and internal membranes that keep the embryo moist; a major adaptation to life on land characteristic of reptiles, birds, and egg-laying mammals.
The hardened remains or other evidence of a living thing that existed a long time ago.
Rock formed of hardened layers of sediments.
A scientist who studies extinct organisms, examines fossil structure, and makes comparisons to present-day organisms.