Abstract:
Fossil closed-cone pines similar to Californian species that
now inhabit maritime and interior areas were alreadv established
as distinct adaptive groups in Miocene time. Th~ir fossil associates
suggest that floristically the closed-cone pine forests
are part of the Madro-Tertiary Geoflora. Species ancestral to the
pines and their associated endemics evidently represented members
of a highly temperate phase of the geoflora that reached the
coastal strip in Oligocene time. The pines and their associates
probably did not evolve in insular isolation, but in the temperate
uplands in the interior. As more extreme climates developed
there, the pine forests migrated coastward to survive under mild
maritime climate, and also southward where related species persist
in the uplands of Mexico under highly temperate climate.