The vertebrates traditionally include the hagfish, which do not have proper vertebrae, though their closest living relatives, the lampreys, do have vertebrae. Hagfish do, however, possess a cranium. For this reason, the vertebrate subphylum is sometimes referred to as "Craniata" when discussing morphology. Molecular analysis since 1992 has suggested that the hagfish are most closely related to lampreys, and so also are vertebrates in a monophyletic sense. Others consider them a sister group of vertebrates in the common taxon of Craniata. Vertebrates are smart. Some of them are very smart. We mean you. Most vertebrates have very advanced nervous systems. While a goldfish might not compare to your intelligence, when you compare a goldfish to a sea anemone, a goldfish is like Einstein. Octopi are probably the smartest invertebrates and may equal or be smarter than some vertebrates. Octopi are the exception in the invertebrate category. More cool traits about vertebrates are that they have muscles and skeletons. While the materials may vary, muscles allow vertebrates to move around very efficiently and perform complex moves. That ability to move and the intelligence to go with it gives vertebrates such as reptiles and birds an advantage in the natural world. This book presents a thorough and accessible account of comparative anatomy of vertebrates and is designed to be useful and effective for the students of zoology, life sciences and other allied fields. The subject matter is as such that it facilitates the students at the graduate and postgraduate level.