Today's penguins represent 60 million years of evolution that produced what are arguably the strangest birds of all time. In the November issue of Scientific American, paleontologists Ewan Fordyce of the University of Otago in New Zealand and Daniel Ksepka of North Carolina State University in Raleigh describe recent fossil discoveries that have, at last, allowed scientists to reconstruct the evolutionary history of these endearing creatures—spanning their origin from a flying ancestor to their spread across the Southern Hemisphere into some of the most forbidding environments on Earth. The slide show below highlights a representative sample of modern penguin species. As varied as they are, modern-day penguins represent but a fraction of the group's past diversity.

» View a slide show of some modern-day penguin species.