The oldest know hominid, or human-like species is a little over 6 million years old and Homo sapiens have only been around for a couple hundred thousand years.  Dinosaurs may have lived a really long time ago, but they were around for even longer than the time difference between their existence and ours.

Also, there was way too much information for one comic here.  Obviously there were way more types of animals than the archosaurs and there were more before their time.  They were just an example because they were fairly dominant and are the ancestors of a lot of today’s animals.  The archosaurs actually evolved from the archosauromorpha’s.