'paleopallial' originates from New Latin/Greek, specifically the combination of Greek 'palaios' and Latin 'pallium', where 'palaios' meant 'ancient' and 'pallium' meant 'mantle'.

'paleopallial' changed from the New Latin term 'palaeopallium' used in anatomical and comparative neuroanatomy in the 19th–20th centuries and eventually formed the adjectival 'paleopallial' in modern scientific English.

Initially it meant the literal 'ancient mantle' (a descriptive, literal formation), but over time it evolved into the current specialized meaning of 'relating to the paleopallium (paleocortex) in vertebrate brains'.