The quagga, who is seen here reading about mammalian phylogeny, is a recently extinct mammal generally related to horses and zebras. It was a yellowish-brown zebra with stripes only on its head, neck and forebody. The quagga was native to desert areas of the African continient until it was exterminated in the 1880's. As an extinct animal, the quagga is well qualified to act as a tour guide for a paleontological museum. As an animal that was living during historical times, the quagga is symbolic of the continuity between the living and extinct.
Placental mammals are one of three major groups of living mammals.
Marsupials , or Metatheria, form another. This group includes all of the pouched animals, such as oppossums, kangaroos, and Tasmanian devils. The third group, the monotremes , are far less diverse and less well known. They are warm-blooded, have hair, and produce milk just like other mammals, but they lay eggs and do not give live birth like marsupials and placentals. A fourth major group, the Multituberculata , are entirely extinct, though they were once widespread and successful.