| a•nat•o•my
[əˈnatəmē] the branch of science concerned with the bodily structure of humans, animals, and other living organisms, especially as revealed by dissection and the separation of parts; the bodily structure of an organism. phys•i•ol•o•gy [fizēˈäləjē] the branch of biology that deals with the normal functions of living organisms and their parts; the way in which a living organism or bodily part functions. ========== Rodents are the largest group of mammals and include rats, mice, voles, muskrats, nutria, guinea pigs, chinchillas, lemmings, hamsters, gerbils, beavers, capybaras, muskrats, porcupines, woodchucks, chipmunks, squirrels, prairie dogs, marmots, chinchillas, voles and lemmings. Rabbits and hares are closely related to rodents, but are lagomorphs (lagomorphs possess an extra pair of incisors in the upper jaw; are caecotrophagic (they ingest soft faecal pellets taken directly from the anus at night and stored in the stomach to be mixed with food taken during the day); do not possess a baculum; and the scrotum is situated forward of the penis. Shrews, moles and hedgehogs are insectivores, not rodents.
 X-ray image of southern flying squirrel (image courtesy J. Vecoli) |