This species is characterized by the presence of unci, which are paired sclerites often possessing teeth. These unci are located ventroapical to the rami and are proximally articulated with the manubria, forming functional units known as mallei. Unlike Gnathostomulida, unci are present in L. maerski and all jawed rotifers analyzed, including S. nebaliae. In most species, the unci teeth exhibit either a distinct pore or a deep cleft, referred to as the jugal line, located on the external surface of each tooth. However, S. nebaliae and L. maerski lack these structures. Among bdelloids, there is typically a pore present in the distal part of each uncus tooth, while monogononts feature jugal lines.