<Table> <Tr> <Td> Rodentia Chiroptera Soricomorpha Primates Carnivora Artiodactyla Diprotodontia Lagomorpha Didelphimorphia Cetacea Dasyuromorphia </Td> <Td> Afrosoricida Erinaceomorpha Cingulata Peramelemorphia Scandentia Perissodactyla Macroscelidea Pilosa Monotremata Proboscidea </Td> </Tr> </Table> <Tr> <Td> Rodentia Chiroptera Soricomorpha Primates Carnivora Artiodactyla Diprotodontia Lagomorpha Didelphimorphia Cetacea Dasyuromorphia </Td> <Td> Afrosoricida Erinaceomorpha Cingulata Peramelemorphia Scandentia Perissodactyla Macroscelidea Pilosa Monotremata Proboscidea </Td> </Tr> <P> Mammalia is a class of animal within the Phylum Chordata . Mammal classification has been through several iterations since Carl Linnaeus initially defined the class . No classification system is universally accepted; McKenna & Bell (1997) and Wilson & Reader (2005) provide useful recent compendiums . Many earlier ideas from Linnaeus et al have been completely abandoned by modern taxonomists, among these are the idea that bats are related to birds or that humans represent a group outside of other living things . Competing ideas about the relationships of mammal orders do persist and are currently in development . Most significantly in recent years, cladistic thinking has led to an effort to ensure that all taxonomic designations represent monophyletic groups . The field has also seen a recent surge in interest and modification due to the results of molecular phylogenetics . </P> <P> George Gaylord Simpson's classic "Principles of Classification and a Classification of Mammals" (Simpson, 1945) taxonomy text laid out a systematics of mammal origins and relationships that was universally taught until the end of the 20th century . </P>

Where do mammals fit in the classification of animals