Quasillites is distinguished from other ostracodes by the presence of a "medial spot" on each valve. The ribs and
spines on the
carapace are in front of the posterior margin, and are similar to those of other ostracods such as
Bufina,
Parabufina, and
Healdia. In fact, this comparison can also be drawn for all Quasillitids to other Healdiids. The muscle scars on each valve is circular in shape, and some specimens have smaller secondary scars. ==Distribution==