Vertebrate Classification Flashcards

Class Agnatha: Includes jawless fish such as lampreys and hagfish.
Class Chondrichthyes: Comprises cartilaginous fish like sharks, rays, and skates.
Class Osteichthyes: Consists of bony fish, including catfish, bass, goldfish, and features ray-finned (salmon, eels) and lobe-finned types.
Class Amphibia: Encompasses frogs, toads, salamanders, and newts, requiring moist environments for reproduction.
Class Reptilia: Contains turtles, snakes, lizards, alligators, and crocodiles, characterized by scales and leathery-shelled eggs.
Class Aves: Represents birds, most of which are capable of flight and lay shelled eggs.
Class Mammalia: Includes mammals such as humans, bats, dolphins, and whales, known for feeding young with milk and possessing hair.

Digestive systems are predominantly one-way, with instances of cloacas in sharks and birds.
All classes possess a brain and spinal cord in their nervous systems.
Reproductive methods vary: external in Agnatha, Osteichthyes, Chondrichthyes, and Amphibia; internal in Reptilia, Aves, and Mammalia.
Circulatory systems vary by class:
- Agnatha, Chondrichthyes, Osteichthyes: 2 chambers
- Amphibia, Reptilia: 3 chambers
- Aves, Mammalia: 4 chambers

Aves employ a unique respiratory system with air sacs and continual airflow in lungs due to air-filled bones.
Excretory systems in Reptilia primarily utilize lungs; Amphibia utilize both gills/lungs and kidneys.

Agnatha: Lack scales and swim bladders.
Chondrichthyes: No swim bladders, possess cartilaginous structures, ventral mouths, and scales.
Osteichthyes: Have operculum, scales, and swim bladders.
Amphibia: Require moist habitats for reproduction and have thin skin.
Reptilia: Characterized by their scales and leathery-shelled eggs.
Aves: Features feathers and the ability for most species to fly.
Mammalia: Notable for milk-feeding young and the presence of hair.