PBS Eons has another episode.  This one is about the origins of pterosaurs.  Although the evidence is pretty sparse, we aren’t sure of their ancestors.  Scleromochlus, or something like it, is a likely candidate.  Watch the episode for more details…

When pterosaurs first took flight, you could say that it marked the beginning of the end for the winged reptiles. Because, strangely enough, the power of flight — and the changes that it led to — may have ultimately led to their downfall.