paleopallium

noun

pa·​leo·​pal·​li·​um

variants or British palaeopallium

-ˈpal-ē-əm 

plural paleopallia -ē-ə  or paleopalliums

: a phylogenetically old part of the cerebral cortex that develops along the lateral aspect of the hemispheres and gives rise to the olfactory lobes in higher forms