Complex sentence: It was originally classified as a plutino with a 2:3 mean-motion resonance with Neptune, but further observations have established that it is a "cubewano"--a member of the classical Kuiper Belt.
Split into simpler sentences: It was originally classified as a plutino with a 2:3 mean-motion resonance with Neptune. However, later studies have shown that it is infact not a plutino at all, rather, it is a "cubewano"-a member of the classical Kuiper Belt.