ACtually, the Karaites took after the SAdducees/Zadokim.
Karaites are Jews.
Interestingly, the Nazis did NOT consider Karaites they encountered in the Russian Caucasus to be Jews. If you're not following the Oral Torah, you're not a Jew, you're a
minim. And what separates Jews from every one else is the belief God gave Moses a separate set of teachings to explain what the Written Torah meant.
(Denny Crane: "Sometimes you can only look for answers from God and failing that... and Fox News".)