The incredible diversity of pterosaurs is perhaps best expressed in one of the prehistoric flying reptile’s most intriguing and mysterious features: the head crest.
Scientists have many theories about why crests evolved. Theories include recognizing one's own species, cooling, and steering. Without living descendants for comparison and because pterosaur fossils are so rare, it's impossible to say for sure. Researchers would have to find thousands more fossils in different growth stages to answer the question.