Flight has evolved three times among vertebrates: Pterosaurs, Birds and Bats. In all three cases it is an example of convergent evolution; all evolved independently of one another. While all three are completely unrelated, they do share some similar morphological features. The reason for this is that the requirements of an aerial existence are high and demand very specific adaptations. Pterosaurs are reptiles and therefore have had to undergo extensive modification of their morphology. The most obvious modification is the change of the forelimbs into wings. There are many modifications and the following pages will discuss some of the more obvious ones. |
The Wings |
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Pterosaur wing. |
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© Patrick Lyons 1998. |