Figure 13. Area plot of the mammalian families represented in the biostratigraphic survey data, based on proportion of specimens that could be identified at least to family (NISPF).  Surveys are arranged from oldest to youngest, left to right.  “Other” includes aardvark, carnivore, chalicothere, rodent, and primate.  Equidae includes only species of the genus Hipparion.  Data in Table 7.