Complex sentence: The family is closely related to the Anomiidae (saddle oysters), one of the main differences being that the Placunidae do not attach themselves to a hard surface-instead they are a mud-living family.
Split into simpler sentences: The family is closely related to the Anomiidae (saddle oysters). One of the main differences is that the Placunidae do not attach themselves to a hard surface-instead they are a mud-living family.