Kimmeridgean is a coordinate term of oxfordian.
As a noun oxfordian is
a native or resident of oxford.
As a proper noun oxfordian is
(geology) the age from 1635±10 ma to 1573±10 ma or the stage of rocks (chiefly coral-derived limestones) deposited during it.
As an adjective oxfordian is
of or pertaining to oxford or its residents.