| A | B |
|---|
| placoderms | Members of an extinct class of fishlike vertebrates that had jaws and were enclosed in a tough, outer armor. |
| Class Chondrichthyes | The vertebrate class of cartilaginous fishes, represented by sharks and their relatives. |
| Lateral Line System | A mechanoreceptor system consisting of a series of pores and receptor units(neuromats) along the sides of the body of fishes and aquatic amphibians; detects water movements made by an animal itself and by other moving objects. |
| Oviparous | Referring to a type of development in which young hatch from eggs laid outside the mother's body. |
| Ovoviviparous | Referring to a type of development in which young hatch from eggs that are retained in the mother's uterus. |
| viviparous | Referring to a type of development in which the young are born alive after having been nourished in the uterus by blood from the placenta. |
| Cloaca | A common opening for the digestive, urinary, and reproductive tracts in all vertebrates except most mammals. |
| Class Osteichthyes | The vertebrate class of bony fishes, characterized by a skeleton reinforced by calcium phosphate; the most abundant and diverse vertebrates |
| swim bladder | An adaptation, derived from a lung, that enables bony fishes to adjust their density and thereby control their buoyancy. |
| Class Amphibia | The vertebrate class of amphibians, represented by frogs, salamanders, and caelcilians. |
| extraembryonic membranes | Four membranse, (yok sac, amnion, chorion, allantois) that support the developing embryo in reptiles, birds, and mammals. |
| Class Reptilia | The vertebrate class of reptiles, represented by lizards, snakes, turtles, and crocodilian. |
| ectotherms | Animals, such a a reptile, fish, or amphibian, that must use environmental energy and behavioral adaptations to regulates its body temperature. |
