Cerebral Hemispheres / Cerebrum

agnathans

barely noticeable; cavities (lateral ventricles) are rudimentary

elasmobranchs

better developed

consists of basal ganglionic mass (corpus striatum) and a thin dorsal epithelial layer (palium) 

composed of non-nervous tissue

bony fishes

better developed

roof is thin and non nervous; not equivalent to the pallium of other animals

thick corpus striatum + undivided lateral ventricles

amphibians

pallium is invaded by nerve cells --> becomes enlarged with more complex activities

corpus striata form a thick floor of the cerebrum

reptiles

increased in size due to the invasion of pallium

greater thickness and enlargement of corpora striata

cerebrum nerve center

birds

very large → covers the diencephalon and optic lobes

Large due to the enlargement of corpus striatum → makes lateral ventricles small

mammals

dominant in the brain; coordinating centers

presence of corpus callosum

prototheria

in mammals, this is small and smooth

metatheria

in mammals: large and smooth

eutherians

mammals: divided into lobes that have gyri (ridges) and sulci (depressions); projects above the olfactory lobes and the diencephalon + midbrain