Sciurognathi is a suborder of rodents that includes squirrels, chipmunks, beavers, and many types of mice. Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria Placozoa Subregnum Bilateria  Acoelomorpha  Orthonectida  Rhombozoa  Myxozoa  Superphylum Deuterostomia     Chordata (vertebrates, etc. ... Typical Classes Subphylum Urochordata - Tunicates Ascideiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Orders Subclass Monotremata Monotremata Subclass Marsupialia Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Subclass Placentalia Xenarthra Dermoptera Desmostylia Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia The mammals are the class of vertebrate animals characterized by the presence of mammary glands... Eutheria is a classification system nearly synonymous with Placentalia. ... Families Many, see text The order Rodentia is the most numerous of all the branches on the mammal family tree. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... Superfamilies Dipodoidea (2 families) Muroidea (6 families) Myodonta is an infraorder of rodents that includes Jerboas, hamsters, and many types of mice and rats. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... Genera Many, see the article Sciuridae. ... Species Genus: Tamias Tamias alpinus (Alpine Chipmunk) Tamias amoenus (Yellow pine Chipmunk) Tamias canipes (Gray-footed Chipmunk) Tamias cinereicollis (Gray-Collared Chipmunk) Tamias dorsalis (Cliff Chipmunk) Tamias merriami (Merriams Chipmunk) Tamias minimus (Least Chipmunk) Tamias obscurus (California Chipmunk) Tamias ohrogenys (Yellow-cheeked Chipmunk) Tamias palmeri (Palmers Chipmunk) Tamias... Species C. canadensis C. fiber Beavers are semi-aquatic rodents native to North America and Europe. ... For the input device, see computer mouse. ...