This allows for the study of the transition between dinosaurs and ancient mammals; research is ongoing.
Mongolia's ancient mammals are under stress from prolonged drought.
The site is especially important as a source of fossils of ancient mammals which, at that time, were small creatures living in a world dominated by dinosaurs.
In the war for the future of the black rhinoceros, one of the planet's most ancient and endangered mammals, Zimbabwe has been an embarrassing rout.
"On Earth we believe that men evolved from a protohominid, which in turn derived from an ancient mammal; and so on back to the first cells."
My people, I believe, are descended from the ancient winged mammals who used to live on Zylor.
It's an ancient mammal.
A large proportion of the brain is the olfactory bulb in these ancient mammals, according to the text of this article.
This ancient mammal was probably something like our modern shrews.
Elasmotherium (meaning "thin plate beast") was an ancient plant-eating mammal that lived during the Pleistocene epoch.