Comprehensive A-Z list of animals for easy identification. Lists include vertebrates, invertebrates, mammals, birds, reptiles, amphibians. Additional lists cover fish, arthropods, mollusks, and echinoderms
Rodents are the largest mammal group with over 2,050 species. They possess constantly growing rootless incisors with sharp chisel edges. Body size ranges from 5-7g swamp mouse to 3,000g marmot. Powerful masseter muscles enable chewing and gnawing
Vertebrates are animals with backbones and muscular systems. Approximately 45,000 living species exist worldwide. Range in size from tiny fishes to elephants and whales. Found from Arctic to tropics, absent from Antarctic interior
Vertebrates possess a vertebral column and skull, making up the largest group in Chordata. They possess a notochord, hollow nerve cord, endostyle, and paired pharyngeal gills. Vertebrates are mirror-symmetrical and move using muscles along the back
Segmentation divides body plans into linear repetitive segments. Segmentation allows free movement and development of body parts. Different taxa use different segmentation mechanisms
Rodents are small to medium-sized mammals with continuously growing incisors. They comprise about 40% of all mammalian species. Size ranges from 3.5 oz to 146 lbs, with males sometimes larger than females. Have cheek pouches, five digits on forelimbs, and well-developed sensory organs