Craniate with well-defined heads, thus excluding members of the chordate subphyla Tunicata (tunicates) and Cephalochordata (lancelets), but including Myxini, which have cartilaginous skulls and tooth-like structures composed of keratin. Craniata also includes all lampreys and armoured jawless fishes, armoured fish, sharks, skates, and rays, and teleostomians: spiny sharks, bony fish, lissamphibians, temnospondyls and protoreptiles, sauropsids and mammals. The craniate head consists of a brain, sense organs, including eyes, and a skull. In addition to distinct crania (sing. "cranium"), craniates possess many derived characteristics, which have allowed for more complexity to follow. Molecular-genetic analysis of craniates reveals that, compared to less complex
An Introduction to Animals and Political Theory normative political theory asking to what extent animals should be included in the domain of justice. States can and do regulate human-animal relationships, whether the animals in question are used in agriculture, as companions, or in some other way. Cochrane's focus is not on why laws are passed or on comparing laws, but in exploring what kind of laws "should" be passed. As his focus is on political theory, he is less concerned with questions about individual moral obligations than he is with institutional arrangements. He notes, however, that questions about animals have been neglected in political theory. In the