brachycephalic vs brachycranic

brachycephalic is a noun but brachycranic is not a noun.

Word	Noun	Adjective	Verb	Adverb
brachycephalic	Yes	Yes	No	No
brachycranic	No	Yes	No	No

As adjectives, brachycephalic and brachycranic are synonyms defined as:

brachycephalic and brachycranic: having a short broad head with a cephalic index of over 80

Other synonyms of brachycephalic include brachycranial.

brachycephalic (noun)	brachycranic (noun)
an adult with a short broad head

brachycephalic (adjective)	brachycranic (adjective)
having a short broad head with a cephalic index of over 80	having a short broad head with a cephalic index of over 80