Complex sentence: The dugong (UK:; US:), "Dugong dugon", a large marine mammal, is one of four living species of the order Sirenia, which also includes three species of manatees.
Split into simpler sentences: The dugong (UK:; US:, "Dugong dugon") is a large marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees.