More than 4,000 specimens of fruits and seeds were extracted
from the matrix removed from inside the skulls of sabre-tooth cats
excavated from various pits in the Rancho La Brea deposits. Of this
number, spproximately 1,445 specimens are involved in this study.
Many comparisons with modern fruits and seeds made it possible to
make identification of this material. There are 15 families comprising
20 genera and 30 species recorded in this report of the
Rancho La Brea Pleistocene flora. Of this number, four species
and four varieties are new to the Pleistocene floras. Eleven of the
30 species occur in the flora of the area today, eleven now occur in
areas so remote from the Rancho La Brea site that they could not
have been carried by flood waters into the areas of deposition, and
therefore, must have been living near to the asphalt beds in order
that entrapment could occur. Eight of the species are now extinct.
Based on the requirements of their modern counterparts,
ecologically, many of the species live in riparian situations or more
moist locations than prevail today in the area of deposition. The
average rainfall for the range of a number of the modern representatives
of the fossils was correlated. From these data it appears that
the climate may have been cooler and more moist during the period
of deposition, and the species occurring in southern California at
that time would have required 2- to 25 inches for their continued existence.
It may be assumed that when this average dropped below
20 inches for long periods of time, the species either receded to
areas with suitable rainfall or became extinct.