Palaeos		Pterosauria
The Vertebrates		Overview

Pterosauria

ARCHOSAURIA
|--CROCODYLOMORPHA
`--+--DINOSAUROMORPHA
   |
   `--PTEROSAURIA 
      |--Dimorphodontidae 
      `--+--Campylognathoidea 
         `--+--Rhamphorhynchoidea 
            `--Pterodactyloidea 
               |--Ornithocheiroidea 
               `--+--Ctenochasmatoidea 
                  `--+--Dsungaripteroidea 
                     `--Azhdarchoidea

Introduction

The Pterosaurs may or may not belong here, between the crocs and the dinosaurs. There is a strong minority opinion that they are more basal archosauriforms -- or perhaps an even earlier diapsid clan. Like birds, much of the body and its skeleton have been highly modified for flight. Also like birds, the skull has also been reengineered, perhaps to an even greater degree than in birds, but for reasons which are much less easy to determine.  Fortunately, the sequence of events within the pterosaurs is somewhat easier to work out than in modern birds, or even bats. (ATW 020327)