Tupandactylus imperator
"Emperor Tupan finger "

 Tupandactylus (named for Tupan, god of the Brazillian Tupi people--pterosaurologists love using Amerindian gods as genus names) was one of several American pterosaur species with large or elaborate crests. There are two species of Tupandactylus. T. navigans (which was featured in the series Walking With Dinosaurs) had a tall, rounded crest, while T. imperator, pictured here, took the smaller crests of earlier tapejarids to an elaborate extreme. These were both originally classified in the genus Tapejara, but more recent studies show that they belong in a seperate genus, and some suggest splitting them even further, removing T. navigans from Tupandactylus. It was included within the genus Ingridia, but due to a real taxonomic tangle, Ingridia is invalid and if re-classified, T. navigans will need a new name. As you can see, the emperor tupan had a bony crest similar to Tapejara, with a large crest above it's beak and a long prong on the back of the skull. The snout crest here developed an extremely long protrusion, and fossils show that these two struts supported a "sail" of keratin. It is usually thought that such crests were used for display. An even more extreme example of this comes in the form of the preposterously large crest of Nyctosaurus.

  The wingspan of the emperor tupan is unknown, as only the skull has been found for both species, but it was probably a medium sized pterosaur of around fifteen feet. It lived in the middle of the Cretaceous period (Aptian age) in what is now Brazil.