The proposal for this book was chosen by the Open SUNY Textbook program in March 2014. The book represents nine months of writing and research. Three students helped me immensely during the project. Tyler Blank spent an entire semester researching new discoveries and editing and indexing the manuscript. Keenan Taylor spent a semester researching relevant ecology and anatomy in order to produce his beautiful illustrations that greatly enrich the book. Finally, Blain Shinkle had the daunting task of bringing order to the references that I cited. Many thanks to the external reviewer, Dr. Kristi Lewton, a biological anthropologist and evolutionary anatomist at Boston University. She expertly edited the manuscript and greatly improved it. Many times I was so caught up in thinking and writing that I neglected grammar and forgot the reader; Kristi consistently and gracefully put me back on track.