Although they came into their own only after the extinction of the dinosaurs some 65 million years ago, mammals had maintained a low-profile existence for some 150 million years before that. New ...

DR. G. D. H. CARPENTER (NATURE, March 20, p. 46) asks why we should suppose that the occurrence of tsetse-flies (Glossina) in the Miocene of Colorado might have had anything to do with the extinction ...

THE White River formation of western North America contains numerous well-preserved fossil skeletons of mammals which date back to Oligoeene times when some present-day families were beginning to ...

This is a preview. Log in through your library . Abstract The epochs of a period in the Tertiary time scale are, supposedly, convenient terms of expression, and Lyell's original designations have been ...

The Changing Globe -- The Changing Face of the Earth -- Vendian Times -- Early Cambrian Times -- Late Cambrian Times -- Ordovician Times -- Silurian Times -- Devonian Times -- Carboniferous Times -- ...

Fossil seal remains from Richmond, Virginia, first reported by Wyman in 1850, and named Phoca wymani by Leidy in 1853, have been neglected and unjustifiably regarded as cetacean by most subsequent ...