These are the most frequently used words in this book.
1987
1990
1991
1992
1993
1994
1995
1997
1999
al
although
america
ancient
angiosperms
appear
approximately
areas
atmospheric
between
biome
cells
changes
climate
co2
conditions
conifers
cretaceous
diversity
dna
during
earliest
early
et
events
evidence
evolution
evolutionary
example
extant
extinction
families
ferns
figure
first
floras
forest
form
formation
fossil
geological
global
groups
hemisphere
high
however
including
increased
indicate
land
late
leaf
leaves
ma
major
mass
may
million
north
number
occurred
part
periods
plant
pollen
present
process
record
redrawn
regions
seed
southern
species
stem
structure
studies
suggested
suggests
taylor
temperate
temperatures
therefore
thus
time
trees
tropical
two
vascular
vegetation
warm
years