from wikipedia: "Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups."

• the independent development of flight in birds, mammals (bats), and insects
• carcinization - crustaceans which are not crabs evolving into the form of a crab, happens often enough that this unique name was coined for it
• peregrine falcons, despite also being birds of prey and sharing similar characteristics with hawks and eagles, are much more closely related to parrots
• the independent development of gliding in flying squirrels and sugar gliders
• the independent development of stingers in stinging insects (wasps, bees, etc.), cone snails, stingrays, stinging nettles, etc.
• the independent development of echolocation in bats and whales