Sphaerosyllis levantina is a species belonging to the phylum Annelida, a group known as the segmented worms.

The authors then re-examined material of Sphaerosyllis hystrix from previous finds, which revealed some individuals possessed a subdistal spine on the blades of anterior falcigers and also in posterior chaetigers.

To clarify the relationship between the new specimens and the 2 described species possessing falcigers with a subdistal spine, the scientists conducted a morphometric analysis.

Its prostomium is wider than long, with 4 coalescent lensed eyes arranged trapezoidally; anterior eyespots are absent.

All of these species differ from Sphaerosyllis levantina by lacking a subdistal spine on the falcigers' blades.

S. boeroi, in turn, differs from S. levantina in having significantly longer falciger blades, which simultaneously show more pronounced dorso-ventral gradation.

S. hystrix can be distinguished from S. levantina by showing smooth or finely serrated posterior falcigers, even when the spine is present.

[1] S. levantina was found in fine to medium sands in Haifa Bay, at a depth of 10.5 metres (34 ft).