Via: TVtropes.org
Trope Codifier – does not claim originality, but is the template that all later uses of this trope follow.
In other words, if in tracing the history of a trope, one example stands out as the template that many, many other examples follow, that’s the Trope Codifier.
Aladdin is the Trope Codifier in Western Animation for the value of star power in casting voice actors.
And, as expected, TV tropes as a whole lexicon of these terms beyond Trope Codifier and Ur-Example including Trope Maker and The Most Triumphant Example.