Excerpt:
Major mammal groups appeared before dinosaurs died out, study says
NEW YORK (AP) Maybe you learned it in school: Mammals waited until the
dinosaurs died out before they started diversifying into the variety of
major groups seen today.
That's what the fossils say. But a new [molecular clock] study says it isn't
so. Most of the modern groups, or "orders," of mammals apparently began
before the dinosaurs met their doom 65 million years ago, researchers
conclude.
The work suggests at least five major lineages, which today include such
creatures as rodents, elephants and armadillos, might have appeared more
than 100 million years ago.
....