The longnecks of course didn't save the world. It was just a solar eclipse. One can assume that such a natural even would be quite confusing and scary for dinosaurs who know nothing about its real origins. Maybe the whole thing can be compared with some elements of human religion.
I found it rather strange that a common dream brought all these longnecks there, but it were certainly not all. Where was Ali's herd? Where was Bron's herd? Where was Doc? etc.
