<Ol> <Li> The archipallium or primitive ("reptilian") brain, comprising the structures of the brain stem--medulla, pons, cerebellum, mesencephalon, the oldest basal nuclei--the globus pallidus and the olfactory bulbs . </Li> <Li> The paleopallium or intermediate ("old mammalian") brain, comprising the structures of the limbic system . </Li> <Li> The neopallium, also known as the superior or rational ("new mammalian") brain, comprises almost the whole of the hemispheres (made up of a more recent type of cortex, called neocortex) and some subcortical neuronal groups . It corresponds to the brain of the superior mammals, thus including the primates and, as a consequence, the human species . It should be noted that similar development of the neocortex in mammalian species unrelated to humans and primates has also occurred, for example in cetaceans and elephants; thus the designation of "superior mammals" is not an evolutionary one, as it has occurred independently in different species . The evolution of higher degrees of intelligence is an example of convergent evolution, and is also seen in non-mammals such as birds . </Li> </Ol> <Li> The archipallium or primitive ("reptilian") brain, comprising the structures of the brain stem--medulla, pons, cerebellum, mesencephalon, the oldest basal nuclei--the globus pallidus and the olfactory bulbs . </Li> <Li> The paleopallium or intermediate ("old mammalian") brain, comprising the structures of the limbic system . </Li> <Li> The neopallium, also known as the superior or rational ("new mammalian") brain, comprises almost the whole of the hemispheres (made up of a more recent type of cortex, called neocortex) and some subcortical neuronal groups . It corresponds to the brain of the superior mammals, thus including the primates and, as a consequence, the human species . It should be noted that similar development of the neocortex in mammalian species unrelated to humans and primates has also occurred, for example in cetaceans and elephants; thus the designation of "superior mammals" is not an evolutionary one, as it has occurred independently in different species . The evolution of higher degrees of intelligence is an example of convergent evolution, and is also seen in non-mammals such as birds . </Li>

Which brain region is not part of the limbic system