If you accidentally hit one of them and an entire swarm chases after you, the easiest way to deal with it is to use a pteranodon and barrel roll through the swarm. This will deal damage to every dimorphodon in the swarm and if your pteranodon has enough melee damage (700%+) you should be able to one hit kill most of them. Pteranodon also speed up drastically while doing the barrel roll so the dimorphodons can’t really hit it as it yeets past them.

More Dimorphodon Encountering Tips