1947] 
Early Insect Life 
71 
This brief survey gives an idea of the extent of the early 
insect life. The fauna was obviously a complex one — 
probably more so than we fully realize, for our present 
roster of the orders existing at the time is surely far from 
complete. Nevertheless, the variety of insect types proba- 
bly fell far short of that which exists now, their biological 
environment being relatively simple. The plants of the 
time were largely seed-ferns and other gymnosperms ; 
angio sperms were entirely absent, and, incidentally, did 
not arise for many millions of years later. It is difficult 
for us, living at a time when angiosperms dominate the 
plant world, to imagine a time of their complete absence ; 
and equally difficult to imagine an extensive insect fauna 
without them. Also, there was a complete absence of 
birds and of mammals. Insects were then the only flying 
creatures on earth; they could readily escape by flight 
from their amphibian and reptilian enemies without 
danger of pursuit. Certainly the life of the insects must 
have been very different then from what it is now — with 
birds, bats, man, and DDT. 
Our knowledge of the habits, life histories, and food of 
these early insects is necessarily slight, but certain infer- 
ences can be made from their structure, as we now know 
it. Let us see what this was like and what conclusions 
can be reached. 
The order Pakeodictyoptera, which existed during the 
Upper Carboniferous and Permian, is a negative and ill- 
defined group. Attempts to divide it into two or more 
orders have not proven successful, because some species 
seem to merge into the Ephemerida, and others into the 
Orthopteroids. Nevertheless, I believe that most of the 
one hundred fifty species which have been described are 
members of one order. Their closest living relatives are 
the Ephemerida and, to a lesser extent, the Odonata. The 
fact that all complete specimens are preserved with their 
wings outspread shows that, like the Ephemerida and 
Odonata, they were palaeopterous, i.e., unable to fold their 
wings back over the abdomen at rest. They had nearly 
similar fore and hind wings and were apparently weak 
fliers. Although they are mostly preserved as isolated 
