Species affinis

Species affinis (commonly abbreviated to: sp., aff., or affin.)

In open nomenclature it indicates that available material or evidence suggests that the proposed species is related to, has an affinity to, but is not identical to, the species with the binomial name it comes after.

[1] The Latin word affinis can be translated as "closely related to", or "akin to".

alone, implies that the specimen differs suggestively from the holotype but that further progress is necessary to confirm that it is a novel species.

In a suitable context it also may suggest the possibility that the shell belongs to a species that has not yet been described.