Complex sentence: In 1986, he proposed a classification system of seed plants, spermatophytes, and divided the Spermatophyta into 10 subdivisions, including the flowering plants Phanerogamophytina.
Split into simpler sentences: In 1986, he proposed a classification system of seed plants, spermatophytes. He divided the Spermatophyta into 10 subdivisions, including the flowering plants Phanerogamophytina.