Complex sentence: Morningside College teams, nicknamed athletically as the Mustangs (formerly known as the "Chiefs"), are part of the National Association of Intercollegiate Athletics (NAIA), primarily competing in the Great Plains Athletic Conference (GPAC).
Split into simpler sentences: Morningside College teams are known as the Mustangs (formerly known as the "Chiefs"). The college is a member of the National Association of Intercollegiate Athletics (NAIA), competing in the Great Plains Athletic Conference (GPAC).