A System of World Mammal Faunal Regions. I. Logical and Statistical Derivation of the Regions

Philosophies underlying past classifications of world faunal regions have fostered the view that such units can have little more than heuristic value. Contributing to this feeling is the difficulty attending assessment of rank relationships among the regional elements of a particular system. In the present study, logical constraints upon the meaning of a satisfactorily efficient hier- archical faunal classification are identified and operationalized into a system of world mammal faunal regions via an iterative procedure involving multi- dimensional scaling. The result is a classification consisting of four regions and ten subregions, each of the latter of which is as unique as it can be with respect to all other subregions while still contributing to logical hierarchical order rela- tionships within the system. The classification is compared to the Sclater-Wallace system and is shown to be both more efficient and more internally consistent. Summary data and statistics pertaining to the new classification are presented and briefly discussed.