Except that this then opens up the far more interesting question of what
complex ecological factors actually killed most pterosaurs.
Competition with birds?
That's one possibility. Why did the ichthyosaurs disappear in the
Cenomanian? Probably some kind of competition, but we're not sure.
Likewise, why were the trilobites in decline long before they
vanished at the end of the Permian.
It's hard to pin down an agreement on competition even when we know
that a new large predator appeared on the scene just at the time of
the decline. Look at the long-running debate over the Pleistocene
megafauna extinction in the Americas, although we've long known that
people showed up shortly before they vanished. -- Jeff Hecht