One of any number of species of
extinct flying
Mesozoic vertebrates. Although these creatures are frequently thought of as "flying
dinosaurs", they actually belong to a unique taxonomic order, Pterosauria. Another popular misconception is that they gave rise to modern
birds, which is not the case. Even the most basic comparison of pterosaur and bird
anatomy shows that birds evolved from a different lineage, probably stemming from the
dinosaurs' order, Dinosauria, to create their own order, Aves.
In many ways the anatomy of pterosaurs resembled that of the modern bat. Pterosaur wings were supported by an extended digit and were made rigid and tear resistant by fibers called actinofibrillae. Fossil evidence also suggests that pterosaurs had fur and unlike most birds most had a mouth full of teeth. Although a large and diverse group of animals, it is believed that most species fed on fish.
A good deal of controversy persists about how pterosaur locomotion occured on the ground. Some palentologists believe pterosaurs walked on all fours with their wings folded. Others suggest that they were bipedal, like modern birds. Although the evidence is inconclusive, skeletal anatomy and recently discovered tracks suggest the former is a more likely possibility.
A good reference on these animals is:
Wellnhofer, Peter. (1991). The illustrated encyclopedia of pterosaurs. New York, NY: Crescent Books
A rather lengthy FAQ is available at:
http://www.geocities.com/CapeCanaveral/Hangar/9020/pterosaur/index.htm
Despite the Webster's definition, the term "pterosaur" is not synonomous with "pterodactyl", a particular species of pterosaur. Such a definition is analogous to saying the term "mammal" means "elephant". Of course subjectivism would suggest that just such a definition of mammal might be found in Webster's had it been written by pterodactyls. Of course, that such a flaws exist in a descriptive dictionary is evidence of the futility of producing such a reference.
A name that PlatyBowiePus and I use to describe belligerent drunks, joking that they are about to go on a disemboweling frenzy.