palaeencephalon vs paleoencephalon

palaeencephalon and paleoencephalon both are nouns.

Word	Noun	Adjective	Verb	Adverb
palaeencephalon	Yes	No	No	No
paleoencephalon	Yes	No	No	No

As nouns, palaeencephalon and paleoencephalon are synonyms defined as:

palaeencephalon and paleoencephalon: the more primitive parts of the brain phylogenetically; most structures other than the cerebral cortex

Other synonyms of palaeencephalon include paleencephalon.

palaeencephalon (noun)	paleoencephalon (noun)
the more primitive parts of the brain phylogenetically; most structures other than the cerebral cortex	the more primitive parts of the brain phylogenetically; most structures other than the cerebral cortex