76 
Indiana University Studies 
Phylogenetic History 
Epoch 
Time estimate, 
millions of 
years 
Geologic events 
History of Cynips 
Upper Cre- 
taceous 
80-60 
Rise of flowering plants 
Origin of oak 
First rise of Rockies 
and Sierras 
Ancestral Cynipidae 
Eocene 
60-35 
Alaskan - Siberian con 
nection maintained, 
climate mild, oak in 
the area 
Differentiation of main 
groups in the family 
Oligocene 
35-20 
Alaskan - Siberian con- 
nection maintained, 
climate mild, oak in 
the area 
Great Plains forming 
Cynips and other mod- 
ern genera in exist- 
ence 
Eastern and western 
subgenera separ- 
ated 
Miocene 
20-7 
Alaskan - Siberian con- 
nection continuous, 
climate more severe 
Rockies elevating, des- 
erts forming in the 
area 
Finally Alaskan land 
connections broken 
Subgenus Cynips moves 
into Eurasia 
Antron and Besbicus 
species differentiate 
on Pacific Coast 
Acraspis, Atrusca and 
Philo nix specific 
stocks arise in south- 
ern Rockies 
Pliocene 
7-1 
Great Valley of Calif. 
in part an inland sea 
Rockies elevated and 
Great Plains become 
semi-arid 
Sierras elevated and 
Great Basin becomes 
more arid 
Specific stocks of east- 
ern subgenera move 
across Great Plains 
Modern species and 
varieties differenti- 
ated in all groups 
Pleistocene 
1 million to 
20,000 years 
Grand Canyon begun 
Extensive glaciation 
Cold climate south to 
Ohio River 
Moist climate in parts 
of Great Basin and 
north of Gulf of Cali- 
fornia 
Northern varieties 
pushed south to hy- 
bridize with south- 
ern varieties 
Some Calif, species 
migrate back to so. 
Arizona 
