Christopher Sloan is Senior Editor for Art at "National Geographic magazine, where he guides the work of artists on projects ranging from dinosaurs to the frontiers of space. He is also the magazine's specialist for paleobiology. Sloan is the author of several children's books.
Francis Latreille is a celebrated photojournalist and world traveler. He helped create three award-winning magazines before leaving in 1995 to travel across the Arctic and Antarctic. His work has been exhibited in museums and has been featured in magazines worldwide. He lives in France.