Sea turtles are among the most ancient vertebrates on Earth, having existed for more than 120 million years. They are a monophyletic group, comprised of two families and seven extant species. Despite the close phylogenetic relationships sea turtles share, there are significant differences in life history traits and reproductive strategies between the species, including migration, reproductive output, and neonatal behavior. Understanding these differences may be critical to reversing the declining population trends seen in most sea turtle populations.