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 ...

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in ...

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 -- ...

Plates accompanied by guard sheets with descriptive letterpress. https://siris-libraries.si.edu/ipac20/ipac.jsp?&profile=liball&source=~!silibraries&uri=full=3100001 ...