The principal structural feature of the adult Odonates are there adaption for
flight; basically their wings. Adults have two pairs of narrow typically
transparent wings and a long, slender abdomen consisting of 10 segments. The
head has prominent eyes and an inconspicuous antenna; the thorax is tilted to
accommodate the large wing muscles and sets the legs forward. This is so they
can grasp prey, however, they are unable to walk due to this
positioning.
The Odonates have large compound eyes, because of this it is
thought that they have excellent vision. Their eyes are acutely responsive to
movement and form (like T-Rex). The eyes play a key role in capturing food and
interacting with others. In the dragonflies (Anisoptera suborder) the compound
eyes meet at the top of the head and consists of 30,000 optical units. This
gives the Anisopterans a view of 360 degrees. Damselflies (Zygoptera suborder)
have there eyes well separated. Odonates also have three tiny, simple eyes
called ocelli.
Another structural difference occurs at the other end of
the body between the two suborders. Male damselflies have four tail appendages,
whereas dragonflies only have three.