While reading that the cranial crest of the pterosaur Thalassodromeus helped regulate body temperature, I pondered another potential use. While gliding near the water, its crested head might act as a rudder for the large-wingspan animal. Perhaps the crest also included nerves that allowed Thalassodromeus to sense fleeing fish.

Steve M. Adams
Plano, Texas

Perhaps the large crest was for maintaining level flight when catching a fish.