Given the strong interest in ants from a
range of biological disciplines, it is especially
important that we understand the unique
evolutionary history of this group. Fortunately,
during the last decade, a solid foundation
has been established for ant systematics
and, indeed, for ant biology in general
by Ho¨lldobler and Wilson (4) (exhaustive
biological overview), Bolton (7, 8) (taxonomic
catalog and genus-level keys), Ward
et al. (9) (exhaustive bibliographic database),
and Agosti et al. (10) (manual for
using ants as bioindicators). During this
same time period, partial progress toward
reconstructing the subfamily-level phylogeny
of ants has been achieved in studies
using extant species (11–13), but these studies
have been impeded by the lack of critically
informative paleontological data.